These notes are a look at the fruits that are commercially available that we Westerners eat, but from a hunter-gatherer evolutionary perspective. It is a ‘guided tour’, not of the diversity of fruits in the natural environment we evolved in, but rather the fruits that are now commercially available to eat, and how it is we came to be eating only these fruits.
Evolution has forced us to become vitamin C junkies – unlike most animals, we can’t synthesize it ourselves, we have to obtain it from the food we eat. Fruit and vegetables, and to a lesser extent, organ meats, are the prime source.
Only some of the wild fruits that were all around our ancestors have been domesticated. So the number of species available to us now is less – at first glance. But because commerce provides us with fruit from all the continents of the world, our actual daily possible selection range is probably as good as was available to our ancestors. And the fruits we now have available have much fewer unpleasant tannins and glycosides than some of the wild fruits. The fleshy part is larger, and the seediness in some cases reduced or eliminated.
Most people in the West today do not eat enough fruit and vegetables for good health. Those who eat a natural diet, particularly if they have additional supplies from their home orchard, get more than enough, and may need to limit their fruit consumption. But today, such circumstances apply to only the tiniest minority .
The sweet calories of fruit compete with the sweet calories of all manner of ‘junk food’. The difference is that fruit has the soluble fiber, the minerals, the vitamins, the antioxidant chemicals, where ‘junk food’ has few of these – yet demands vitamins and minerals stored from other foods to allow the body to enzymatically process them.
Fruit growers tread a fine line between oversupply of fruit, low prices and resultant penury, and short supply, high prices, and consumer resistance. In the same way, supermarkets value fruit sales as one of the most important ‘profit centers’, and must also tread the line between ‘profit maximization’ and consumer resistance. The commercial availability of a wide variety of fruit at a price affordable to all depends on these tensions not becoming excessive in any one party’s favor.
The urban hunter-gatherer can only look for ‘loss leaders’ at the supermarkets, and seek out subsidized, and therefore cheaper, lines as they become available. In general, canned fruit are nearly as nutritionally valuable as fresh fruit, so they become part of the urban hunter-gatherer’s fruit collection strategy.
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“In the foothills of the mountain areas of…Turkestan, there are also forests of fruit trees. In some regions walnuts (Juglansregia), as well as apples, form the entire woods…The area of wild apples is extensive. In the Caucasus the fruits of the wild apple are fairly small, but those in Turkestan are comparatively large. Individual trees there bear fruit which is not inferior in quality to that of cultivated forms. Some are of astonishingly large size, and the trees are exceptionally productive. The whole spectrum of transition from the typically small, sour apple to the cultivated, perfectly edible type is found. Among wild apples, Malus pumila with purple-red coloring of the flesh occurs. Here, the whole process of development from wild apples to [human] acceptable forms, by hybridization between the species accompanied by mutation, took place without the intervention of man.” – F. Roach, ‘Cultivated Fruits of Britain’
The origin of the cultivated apple is not definitely known, but the center of origin is probably in the area containing the Caucasus, Central Asia and the Himalayas. The modern cultivated varieties probably derive from the central Asian
As our African ancestors radiated out of Africa through the middle East and up through modern day Turkey and South West Asia they, like the bears, will have eaten wild apples of all kinds – some of the 30 or so species being more palatable than others. Our ancestors radiated straight into woodlands of apple, pear, grape, berry and nut tree (and bears!). Even today, the people of the Northern Caucasus go into the woods to gather wild apples to eat, in spite of the ready availability of commercial apples.
Charred apple remains of have been found inside the prehistoric lake dwellings of Switzerland. It is quite likely that fruit collected from the best trees would have a better chance of survival – spread by humans in their faeces, and if the core was thrown aside near the camp better forms would spring up near habitation. These would in turn be more likely to be eaten, being close at hand, and be further spread to other camps. Until the technique of grafting was invented-very recently, relatively speaking-the best types could only ever be spread by sowing seed. But the process of selecting bigger, sweeter, less acid and astringent apples was probably accelerated even further when the fruit forests of the Caucasus and Turkestan were cleared for growing grains as man became an agriculturist. The local tribespeople left the very best fruiting trees in place – naturally – and any further natural seed distribution by humans would again have been weighted in favor of these better forms. By 4000 BC these tribespeople of the Caucasus had invaded present day Iraq to the east, and southern Europe to the West. No doubt they took supplies of dried fruit, perhaps including shriveled apples, with them. Both bears and man have been responsible for dispersing apple seeds into within South West Asia and Europe, but man has tended to spread improved kinds. Apples were well established in Greece by at least 800 BC, and in Italy presumably as well. Apple trees were introduced to Britain in Roman times and from there to North America by settlers about 1630.
Today, apples are of course grown throughout the temperate, warm temperate, and to small degree, subtropical world.
Apples are an unique fruit in that they have a variety of flavors, degrees of sugar and acid, different flesh textures, and differing juiciness. The number of varieties is legion, but only a very few are produced commercially. Some of the less commercially acceptable varieties are smaller, less juicy, more acid, have very ‘hard’ dense flesh, and probably have a great deal more fiber than more ‘melting’ fine fleshed commercial cultivars. They may perhaps be more like the wild apples our ancestors ate. These connoisseur varieties can be found sold ‘at the gate’ at specialist orchards. Unfortunately, there is a trend to produce and market fruit which are too large, especially for children. And some fruit is picked not fully tree ripened, which can be disappointing. New varieties may alleviate these problems.
Apples vary from a ‘fairly good’ to a ‘very good’ source of vitamin C, as there are significant differences between the varieties. ‘Crab apples’, possibly Malus sylvestris, are listed as having very little vitamin C content (compared weight for weight to modern apples). Given the great number of selections of ornamental crab apples, this measurement may not necessarily apply to wild crab apples, or all species of wild crab apples, at least. Apples are a good source of the B vitamin ‘biotin’. Apples are also a good source of a variety of minerals-magnesium, iron, chromium, and manganese. Apples ( as distinct from the expressed juice) are a good source of soluble fiber, which has been shown to slow the release of sugars in the blood and also slightly drop blood cholesterol levels.
Apples have from about 27mg to 300mg per 100 grams fresh weight of of ‘polyphenols’ -substances in plants hypothesised to confer reduced cancer risk benefits ( tests with apple skin extract have been shown to inhibit various cancer cell lines in laboratory bench top tests. Whether ther is a significant effect in humans has not been shown, but it is at least suggestive. For perspective, of the data I have seen, one variety of plum analysed at 4mg/100grams fresh weight at the low end, and a particular variety of grape analysed at nearly 500mg per 100 grams fresh weight at the high end. Further investigations of the total anti-oxidant capacity ( a sum of it’s vitamin C content and other phytochemicals, such as phenols-that turn the flesh brown when left in air- and flavenoids) Eating 100 grams of fresh red delicious apple with the skin on provides the total anti-oxidant activity equal to 1,500 milligrams of vitamin C. The phenolic component of the protective phytochemicals varies from season to season, and it would be reasonable to suppose it varies between different varieties.
Apricot Prunus armeniaca
The apricot is native to Central Asia, with it’s place of first origin thought to be in the hills of Western China. The wild population in the hills of South West Asia, (including Armenia, for which Western botanists named the species) is regarded as a secondary center of diversity. Whatever, the apricot’s wild range is all of Central Asia and parts of South West Asia. The apricot is found semi-wild and wild in the northern hills of China, and in a broad belt across the hills, mountains, and plateaus of Central Asia as far as the Caucasus mountains, between the Caspian and Black seas. Wild apricots are very similar to cultivated varieties, except that the fruit are smaller, as are the stones, with the amount of flesh relative to the stone also being less favorable. Most, but not all, have bitter kernels within the stone. Many parts of the range of the apricot are very dry, and dried apricots may have been a part of the human diet for almost as long as we have been in these regions. The first record of the domestication of apricots is an account of it’s cultivation in China, attributed to Emperor Yu, about 4,000 years ago. We can guess that the tribespeople of Central Asia would have developed ‘traditional rights’ to harvest ‘their’ parts of the apricot forests for millennia before this time. In China, selection by humans was for fruit with non-bitter stones, as well as good fruit. In some of the isolated valleys of the Central Asian Pamir mountains, apricot oil has been the primary oil for cooking, and in China the ‘sweet’ kernels are a valued food item, as well, of course, as the fruit.
Apricots were late coming to the West. It was supposed to have been brought to Greece following Alexander the Great’s invasion of Central Asia. From Greece, the apricot went to Italy, where Pliny referred to it as ‘the Armenian plum’, and eventually arrived in English ‘noblemen’s’ gardens around 1540. From England, the tree was exported with the colonists to the ‘new colonies’ of the British Empire – America, Australia, South Africa and New Zealand.
Modern production has given us larger, brighter fruit, probably with higher vitamin A content. The need to pick and ship firm fruit has also given us fruit that very often have less sweetness, and much firmer flesh than a home tree matured fruit. Curiously, no effort has been made to select for ‘sweet’ kernels in the West, so ‘waste’ stones from canning and drying fruit are presumably used for oil extraction, at best. New techniques in plant breeding are starting to produce some very interesting hybrids between apricots and plums. Some of these are very good eating, but whether their nutritional value – primarily vitamin A content – matches apricots, I don’t know.
Apricot flowers are easily damaged by frost, and the plant really needs a hot, relatively dry growing season. This limits the areas in which apricots can be grown, and in addition, unlike apples, they can’t be stored for months and months and months. This means that apricot production will always be limited.
Dried and canned fruit from areas near their natural range are good value, and their nutritional worth is still very high.
Apricots can’t be regarded as a significant source of vitamin C, but are a good source of vitamin A (as carotene)- one 35 gram apricot has 914 International Units of vitamin A, making them the third richest source of vitamin A of all the common commercial fruit listed on this page. Canned apricots are also good source of Vitamin A, with one canned apricot having very approximately half the content of a fresh fruit.
Apricots are also high in potassium.
Nutritional analysis of a commercial apricot cultivar can be found at the Cape fruits website.
Asian Pear Pyrus pyrifolia ( syn. serotina)
Pears originated in the mountains, foothills, and plateau of Central and South West Asia, in the company of apples, apricots, grapes (in some parts), and various minor fruit not commercially available today. The Asian pear probably originated in the hills of Western China. While this fruit has been familiar to the larger part of humanity for millennia, it has only recently arrived in the west.
Pyrus pyrifolia is thought to be a major contributor to the make-up of the ‘European’ (actually, Central Asian) pear. So, genetically, we are well familiar with this fruit. Pear species in general abounded in the woods and forests of South West Asia as we came out of the Levantine coastal corridor into the wide, wide world of South West Asia and beyond. The pear species seem able to cross with each other without too much difficulty, and some Asian pears are actually complex hybrids between P. pyrifolia, P. ussuriensis, and P. bretschneideri.
‘Asian Pears’ are still something of a novel fruit in the west, and most introductions are from East Asia , and quite recent. Europeans, at least, having been aculturated to ‘European pears’, find Asian Pears don’t have the same depth of flavor. Some varieties of Asian Pear have an extraordinary sweet caramel flavor when fully tree ripened, but these are too ripe to be successfully commercially marketed.
In an attempt to ‘popularise’ Asian pears, they have been crossed with ‘European’ pears to try to create a finer textured flesh, more depth of flavor, and an attractive skin color. Only time will tell whether or not these efforts will bring us a new fruit.
Asian pears can’t be regarded as a significant source of vitamin C, but, as with all fruit, are important for soluble dietary fiber.
Avocado Persea americana
The Avocado is probably descended from a very primitive wild form now limited to a small lowland area of Honduras and a small part of Costa Rica. There are three distinct ‘races’ of avocado (previously regarded as three closely related species) that arose from selection by the early colonizers of South America of better forms from the local wild populations. Primitive wild forms of the Mexican race have been found (guess where?) in Southern Mexico, primitive wild forms of the ‘Guatemalan’ race (the commercially important knobbly skinned ‘Hass’ variety is derived from this race) have been found in isolated parts of Mexico, Guatemala, and Honduras. Similarly, primitive wild forms of the ‘West Indian’ race (the typical thin-skinned tropical avocados are very often derived from this race) have been found in Colombia. The wild avocado in it’s natural range has small fruit, a large stone, and little flesh. Hunter gatherers appreciated this most nutritious of fruits from earliest times- the earliest evidence of human’s association with avocados is from cave deposits in the Tehuacan Valley, near Puebla, Mexico. These deposits have been dated to more than 12,000 years ago. There is some suggestion from archaeological sites that avocados may have been selected for larger fruit size as long ago as 6,000 years ago. Selection by the native inhabitants continued up until their decimation by Spanish and Portuguese tribepeople. In fact, today’s varieties are little improved over the varieties that were being grown by Native South Americans at the time of the European invasion of South America. Avocado fruits are a dream fruit for the human animal – heavy bearing, easily digestible, fruiting all year round (in tropical areas), no toxicity, they store ‘on the tree’ for months, nearly twice the amount of protein as rice, for example, and with a similar calorific value to sustain daily activity.
Native South Americans had introduced the fruit as far south as Peru, and the Spanish continued it’s spread into their colonies in Chile, the West Indies, and their Island colonies off West Africa – Madeira and the Canaries. From there it spread to all the regions where the climate and soil suited it. In recent times, avocado varieties spread mainly from Western USA (California) to former British colonies such as Australia, New Zealand, and South Africa.
It is now grown in virtually all tropical, subtropical, and warm temperate areas with well drained soils and relative frost freedom. In most parts of Europe it is still something of a luxury, whereas in the local areas of production it has become an everyday commodity. In parts of rural South America, and in many poor Pacific Islands, it is an extremely important food.
The more subtropical rather than tropical varieties of avocado have a higher oil content (largely monounsaturated), with a valuable 124 calories per 100 grams. In addition, avocados have up to 4% protein.
Avocados have the highest potassium content of any common domestic fruit (at about 600mg/100gms). While most meats are as high in potassium as fruit, they are accompanied by more sodium (and we add far more in cooking). In hunter gatherer (=natural) times, potassium to sodium ratios were skewed very much more toward high potassium and low sodium than our standard Western urban ‘diet’. High potassium fruits help partially restore the evolutionary balance, and avocados are top performers in the potassium stakes.
While avocados are only a fairly good source of vitamin C, they are rich in many vitamins; avocados have appreciable levels of the B vitamin thiamin (about the same as lamb muscle meat, and better than beef muscle meat.); they also have useful levels of riboflavin (B2), with half an avocado providing about 6% of an adults recommended minimum daily intake. Half an avocado also supplies about 10% of an adults recommended minimum intake of Niacin (B3), and about 15% of an adults daily Pantothenic acid (B5) and pyridoxine (B6) needs. The recommended daily intake of folate is 200mcg ( pregnant women may need more), and half an avocado will fill about a quarter of this required minimum daily quota. Your half an avocado also has around 600 International Units of vitamin A – quite a useful amount.
All in all, avocados are an excellent food for the human animal.
Banana Musa x paradisiaca
Of the 30 or so species of ‘banana’ only two may be regarded as edible, and neither are in our African homeland. There is a wild banana that grows just above the Tropic of Capricorn in sub-equatorial Africa, in rainforests from the west coast across to the East. This species, Ensete ventricosum (previously Musa ventricosum), produces bunches of dry seedy fruit with a small amount of dry and insipid flesh that is eaten only in times of famine.
Wild banana fruits of the two edible species are full of hard, small-pea-sized black seeds embedded in the starchy, sweet/acidulous pulp. The size of the fruit varies according to how many seeds (i.e. how well pollinated the flower was) are present. The more seeds, the larger the fruit. Unpollinated flowers remain as small, empty shells. Within some parts of the wild populations of one of the parents of the modern banana (Musa acuminata), there are genes that result in the plant being able to form fruit (seedless) from an unpollinated flower. Only those flowers in the bunch that are pollinated form seedy fruit, the rest being seedless. A few individuals within the small population of plants that were able to make edible but seedless fruit from the unpollinated flowers in the bunch developed yet another mutation; the female part of all the flowers in the bunch became sterile. Thus no flower forms seeds, and all flowers formed fat, edible, totally seedless fruit. And when our ancestors migrated out of Africa, down thru’ Myanma (Burma), Vietnam and Malaysia, this is the kind of variation they found in the wild banana plants of the forest. Almost all seedy, the occasional one with seedy and seedless fruit in the same bunch, and the odd rare individual with totally seedless fruit. The bananas found in the northern part of the wild range also included natural hybrids between M. acuminata and the more drought and cool tolerant Musa balbisiana. These hybrids had natural ‘hybrid vigor’, growing faster, and having larger bananas, but are usually sterile.
Our ancestors were onto a good thing with bananas. Bananas are easy to propagate, and as our numbers increased we doubtless deliberately increased those clumps that gave some or all seedless fruit. As we moved camp within our territory it would have been easy to carry a small side-shoot plant of our favorite clump with us for re-planting in the new location. Bananas come into bearing in 15 months or so, so it wouldn’t take a lot of fore-thought.
With the coming of slash and burn agriculture, then rice based culture, selection of best types had high pay-off.
So the predominant type became the faster growing M. acuminata x M. balbisiana hybrids, now collectively known as ‘Musa Xparadisiaca’. And these are the bananas of commerce.
The other species of edible banana arose in New Guinea and nearby Pacific Islands. This ‘Fe’i’ group was probably derived from the New Guinean Musa maclayi, but they are now rare. Introduced acuminata/balbisiana varieties have displaced them.
Bananas were introduced to Africa, probably by Indonesian settlers of Madagascar, before 2,500 years ago, and were carried into the Pacific about a thousand years ago.
The banana was taken from the European colonists’ African ‘territories’, to their tropical South American colonies early on. However, mainly the best varieties were taken, which were seed free, sterile varieties. As a consequence, much of the world’s banana biodiversity was left in Asia, and the commercial crops were established on a very, very, narrow genetic base. The precariousness of this has come home in the last 50 years or so as diseases take a toll on the commercial varieties, with no variation in the plants to select disease resistance from. And of course, the wild, seeded types have been dramatically reduced in number due to de-forestation of the land, and in remote village areas, by replacement with better fruiting but seedless varieties.
The huge banana trade in USA and other Western countries developed when a Cape Cod sea captain, Capt. Lorenzo Baker, brought several bunches to Boston, where he found they made good money sold as individual fruit. The bunches had been given him as a gift from a Jamaican plantation owner. What started as an almost accidental item of cargo soon became a regular part of his normal trade with the Caribbean. After fifteen years he founded a company to import bananas on a large scale. He merged his company with a Costa Rican company that had also involved itself in the same trade, and established the United Fruit Company in the late 1890’s.
Refrigeration was developed about this time, and this proved the key to expansion – by the mid 20’s bananas were distributed by refrigerated ship and refrigerated rail cars right throughout the United States, and then beyond.
Today, the major commercial export production plantations are American owned plantations in South America, and to a lesser degree, the Philippines. Half of the world’s banana crop is (still) grown in Africa, where it is eaten locally, both cooked green bananas as a starchy food, and as a ripe fruit full of fruit sugars. Most tropical countries of Asia and South East Asia and the Pacific produce bananas, but, like Africa, almost all of it is consumed domestically.
Bananas are a good source of vitamin C, altho’ an adult would need to eat 6 in a day to get even the rather conservative ‘Recommended Daily Allowance’ of 60mg ( not that anyone relies on a single type of food for their daily vitamin C needs).
Bananas have the second highest potassium content of any common Western domestic market fruit.
They also have useful levels of riboflavin (B2), with one small banana providing about a sixteenth of an adults recommended minimum daily intake. A medium sized banana supplies about a third of an adults recommended daily intake of pyridoxine (B6).
Bananas are probably the most easily digestible fruit there is; while allergies to some fruits are not unknown, it is extremely rare for someone to be allergic to bananas.
Blackberry Rubus species and complex hybrids
The species of blackberry our distant ancestors would have been familiar with is Rubus pinnatus. It produces it’s small, shiny black fruit at forest margins and in tall grass in tropical East Africa down the East coast to the cooler Cape. Various blackberry species (Rubus laciniatus, R. rusticanus, R. nitoides, R. thrysiger, R. coryfolius and others) are native to an area that stretches right across Europe and Asia (some species are regional within this area). Virtually wherever we radiated to, we found blackberries. And when some of our ancestors reached the North American continent, they found various species of blackberry there, too (Rubus allegheniensis, R. argutus, R. setosus, R. cuneifolius, R. trivialis, R. ursinus, and complex natural hybrids between these species). Blackberries would have formed a useful seasonal adjunct to our diet. The plants are usually associated with forest margins and river flats, and were probably not as widespread as after the coming of agriculture, with it’s destruction of forests and new clearings.
Blackberries have only been domesticated very, very, recently – wild berries were always available in hedgerows and woodland margins, and some species were aggressive weeds of pastures and fields, so the idea of deliberately planting them was regarded as madness. But with increasing urbanization, access to wild berries was much reduced, and in from the late 1860’s onward there was an effort to find bigger and better wild berry plants to bring into the garden, especially in America. It is from natural hybrids in America, and selections and hybridization between wild species in Europe, that most of our commercial blackberries come. It would be fair to say that modern blackberries are not much different from wild berries except in size.
Blackberries have a very short shelf life, they are liable to damage in transport and handling, and the plant can be subject to quite a few diseases. When conditions are good, they are very productive, and well suited to ‘commoditization’ as a frozen or pulp product for use in other manufactured ‘foods’. Fresh market berries are consequently relatively expensive, and have a short season. Frozen berries may give best value for money.
At 21 mg of vitamin C per 100 grams, fresh blackberries are a very good source of vitamin C. So about a quarter of a supermarket 250 gram punnet delivers an adult about a fifth (20%) of their daily minimal needs; at the same time it delivers nearly 10% of an adults daily folate (B complex, folic acid) needs.
Blackberries were ranked fourth in tests to identify the most antioxidant rich fruits and vegetables. The natural antioxidant ‘phenols’ in blackberries have been found to have antioxidant properties comparable to fresh grapes and red wines. Interestingly, further studies have shown that blackberries, while having the fourth highest anti-oxidant concentration, are SECOND in actual chemical effectiveness in preventing oxidation in cells. Most of this anti-oxidant activity is in the juicy portion
Laboratory tests also suggest some berries may reduce the buildup of LDL (low-density lipoprotein) cholesterol, a contributor to heart disease, stroke and atherosclerosis. And blackberries were tested as having the highest LDL inhibitory effect. Whether frozen berries have the same protective effect has not been studied – but it would be reasonable to suppose they do. The question of whether frozen berries would give the same effect is as yet unanswered. The phenolic composition of the same berries before and after freezing would have to be tested, as well as testing for the antioxidant activities of frozen berries. But if the antioxidants are still active, it would mean the outstanding power of blackberries’ antioxidants are available year round, not just in it’s normal brief summer season of fresh fruit.
Blueberry Vaccinium angustifolium, V. corymbosum, V. asheii
There is a blueberry native to Africa – Vaccinium exul – but it is limited to the mountains of the eastern part of the Tranvaal province of South Africa, so unless it was more widely distributed in ancestral times, it would not have been a common food item. The 90 or so species of Vaccinium are distributed widely across from Northern Mediterranean, Southern Europe, Central Europe, Northern Europe, North Asia, South Asia, Central Asia, and East Asia. And this includes the 50 or so species native to North America (three of which species have become the blueberries of commerce) and also several South American species.. In other words, wherever we radiated, the bogs, the damp forests, whether temperate or subtropical, broadleaf or conifer, there were blueberries of varying degrees of edibility, productivity and density of population. This is a species with a very long association with the part of the human race that radiated out of Africa.
In the forest-tundra belt of north Europe and North Asia berries of Vaccinium vitis-idaea, and V. uliginosum are still gathered from the wild; in a similar way wild ‘huckleberries’ as well as wild blueberries are gathered by bears and humans alike in North America. Lingonberries (Vaccinium vitis-idaea) are found in the temperate boreal forests from Europe’s North Atlantic shoreline to Eastern Siberia; and down as far as Southern Europe, Albania, and some of the Dalmatian (former Yugoslavia) countries. It too, has been regarded as an important food item, especially in the North, and the bright red berries are still gathered in the wild. One of the advantages of blueberries in general is that they can be dried for use in Autumn and Winter. The indigenous tribes of North America certainly capitalized on this resource in this way, and no doubt other tribal peoples did the same
American species have been cultivated since around 1840, as have some of the European Vacciniums. But it is the North American species that have been perhaps most actively selected and improved, and blueberry culture has not only become relatively extensive in USA, but the North American species have also been imported into other temperate countries of the world to start local industries. In Europe, the lingon berry is commercially produced, and bigger and better varieties are coming on stream.
Blueberries require very particular kinds of soil and moisture conditions, the fruit don’t have a very long shelf life, and are easy to damage in transit. Therefore, the fresh berries will always be relatively expensive. Blueberry plants are very productive, and the fruit are well suited for freezing for use as an ingredient in industrial food. The best value, therefore, is in buying frozen blueberries.
At about 14 mg vitamin C per 100 grams, fresh blueberries can at best be described as a fairly good source for this essential vitamin.
Blueberries were ranked third overall in tests to identify the most antioxidant rich fruits and vegetables. Interestingly, further studies have shown that blueberries, while having the third highest anti-oxidant concentration, are FIRST in actual chemical effectiveness in preventing oxidation in cells. Most of this anti-oxidant activity is in the juicy portion
Laboratory tests suggest some berries may reduce the buildup of LDL (low-density lipoprotein) cholesterol, a contributor to heart disease, stroke and artherosclerosis. In this study, blueberries were tested as having the fourth highest LDL inhibitory effect of all the berries investigated. Whether the powerful antioxidant effect is present in frozen blueberries hasn’t been studied. Commonsense tells us that it is likely that there will be similar levels in frozen fruit as are in fresh fruit.
Recent studies on rats have shown that blueberry extract have actually reversed some of the effects of aging – particularly, loss of balance and co-ordination, a ‘normal’ feature of advancing age. Strawberries and spinach, both with a high antioxidant capacity, improved short term memory-as did blueberry extract; but only blueberry extract reversed the normal decline in motor skills. Whether blueberries will show the same effect in humans has not yet been tested.
While there are specific compounds and combinations of compounds in fruit and vegetable which have either specific or general health benefits, one measurable attribute is the ‘oxygen radical absorbance capacity’ of a fruit or vegetable. This measures the protective effect against oxidative processes suspected to be responsible in part for heart disease and cancers, and particularly responsible for aging – without trying to figure out which natural plant chemical or combination is actually responsible for the protective effect. The ‘ORAC’ for blueberries is not just high, it is astoundingly high, with a quarter of a cup having 800 ‘ORAC units’.(To put it in context, ‘about’ five servings of fruit and vegetables a day yeild a total of 1,600 units.) Blueberries have, on average, 20 ‘ORAC units’ per gram. The average size individual blueberry fruit has 30 ORACs, and large fruited varieties have 40 ORACs per fruit; if all varieties were counted as having the same ORAC levels. But in fact, there are differences between varieties – with the poorest variety and stage of ripeness measuring 15 ORACs/gram, and the best a whopping 40 ORAC units per gram. But, on average, 4 blueberry fruits yeild a massive 100 ORACs!
Generalizing, the highbush types (V. corymbosum) – specifically the commercial varieties ‘Bladen’ (42 ORACs/gram), ‘Rubel’ (37 ORACs/gram), and ‘Rancocas’ (32 ORACs/gram) – and some late harvested rabbiteye types (V. asheii) -specifically the varieties ‘Tifblue’ (38 ORACs/gram) and ‘Brightwell’ (34 ORACs/gram) – have the highest ORAC scores. Wild lowbush (Vaccinium angustifolium) blueberries varied in ORAC by local population – one major area had a mean score of 42 ORACs/gram, another area had a mean of 28 ORAC’s/gram. (Note: all fractions of an ORAC rounded to the nearest whole number).
Ripest berries have the highest ORAC score. Mature berries from ‘Brightwell’ and ‘Tifblue’ had from one and a half to two times higher ORAC score than those picked seven weeks earlier from the same bush. Berries are picked early to secure a better price, or to avoid bruising in transit. Overall, the highest ORAC score comes with the highest anthocyanin content, which comes with the longest time left on the bush to ripe. Pick your own, or grow your own, is generally best.
Blueberries have from about 135mg to 280mg per 100 grams fresh weight of of ‘polyphenols’ -flavenoid substances in plants hypothesised to confer reduced cancer risk benefits. For perspective, of the data I have seen, one variety of plum analysed at 4mg/100grams fresh weight at the low end, and a particular variety of grape analysed at nearly 500mg per 100 grams fresh weight at the high end. This makes them the (commonly available) fresh fruit with the highest polyphenol content.
Vaccinium Antioxidant and Nutraceutical News – JJJ A page at the North American Blueberry Council site which reports and references the studies into the antioxidant effect of blueberries, as well as specific activities against Urinary tract infections, and assistance with eyesight.
Blueberries for health JJ A nice, short, easy read page summing up the health benefits of eating blueberries. At Norris Blueberry Farm site.
Carambola Averrhoa carambola
The carambola originated in Sri Lanka (Ceylon) and the Maluku islands (Moluccas) of the Indonesian archipelago of South East Asia. Human populations radiating into South East Asia would have been familiar with this fruit. Wild plants tend to have fairly acidulous, if refreshing fruits. Carambola is in the family Oxalidaceae, and contains some oxalic acid, which is said to be injurious in large amounts. Judging by it’s use by present day tribal people, our African ancestors almost certainly ate the bulbs and occasionally the leaves of the Oxalis herb that grows wild in parts of Sub Saharan Africa. Our human physiology has been exposed to small amounts of oxalic acid for countless millennia, so on this basis the relatively low amounts in carambola are unlikely to do harm.
It has been carried to China, India, the Philippines, Africa, and virtually all other tropical countries. It was introduced to Florida, USA around 1887. The USDA’s Subtropical Horticultural Research Unit and some Research stations in South East Asia have developed larger and sweeter varieties.
Most Carambola are consumed in the country of origin, and the fruit are something of a luxury item in the supermarkets as a result. Most varieties in Western Supermarkets are low oxalic acid ‘sweet’ types.
One fruit has about a third of the recommended daily requirement of vitamin C, with about 20 mg, so are rated as a good source of Vitamin C; carambolas are also a good source of potassium, and a relatively good source of Vitamin A.
Cherimoya Annona cherimola& Atemoya Annona cherimola x A. squamosa
The Cherimoya and Atemoya of Western commerce have an African relative – the ‘wild custard apple’, Annona senegalensis. This fruit grows throughout tropical Africa, and also the eastern part of Southern Africa. Like a miniature, deep orange skinned, sugar apple (A. squamosa) in appearance, it is said to have a pineapple fragrance and apricot flavored flesh. Unsurprisingly, it is “considered to be one of the best of tropical African fruits”. Another species, A. stenophylla, grows in central Southern Africa, in Botswana and Zimbabwe. This dwarf species has “large, very pleasant tasting fruits”. So Annonaceous fruits are part of the human animals environmental background.
Wild African Annonas have never become an article of commerce. But the two South American species, Annona squamosa (a tropical Annona) and Annona cherimola ( a subtropical to warm temperate species), did. The tropical ‘sugar apple’ is almost impossible to market because it becomes soft to the point of falling apart when very ripe. The ‘cherimoya’ is much larger and has a much better shelf life. Accordingly, the two were deliberately crossed to produce the ‘Atemoya’, a large ‘cherimoya-like’ fruit that grows well in the tropics and subtropics and has a reasonable shelf life.
‘Reasonable’ in the case of cherimoyas and atemoyas is still quite short. The trees require fairly specific soil and climate conditions, which limits their possible range. And so the fruit can only be a luxury item. Given the superb sweetness and flavor characteristics of most of these seasonal fruits, they are a treat worth paying for.
Cherimoyas are a fairly good source of vitamin C . They have useful levels of riboflavin (B2), with a serving sized slice providing about a sixteenth of an adults recommended minimum daily intake, as well as about 5% of an adults minimum daily Niacin (B3) needs.
Wild Annona species- from the Center for New Crops & Plant Products, at Purdue University Site, an extract from Julia Morton’s Book ‘Fruits of warm climates’. Discusses and describes Annona senegalensis, with a little on Annona montana. Also covers origin and distribution, uses. Concise, informative. 1 good photos of A. montana fruit
Cherry Prunus avium
The first ancestral Prunus species probably arose in Central Asia, and gave rise to plums, apricots, peaches, almonds, and cherries. The Center of origin of cherries is probably the western part of Central Asia, and a secondary center of origin is Europe. Sour cherries (often called ‘morello’, or ‘pie’ cherries), Prunus cerasus, evolved from the sweet cherry, perhaps with infusion of genes from another Central Asian Prunus species. There are around a hundred odd of species wild cherry in the temperate zone of Europe and Asia, with most in Asia. Most are bitter, or have very little flesh, although some, such as the Nanking Cherry (Prunus tomentosa), are not bad. The certain fact is, once we radiated out of Africa into Eurasia, our distant ancestors were in cherry territory, and, if we could beat the birds to them (Prunus avium means ‘bird’ prunus), we certainly would have eaten them.
Cherries were probably domesticated around 2,500 years ago in Southern Turkey or Greece. The Romans knew and valued numerous types of better quality cherry, and they spread these forms throughout their empire. With the decline and fall of the Roman Empire, cherries faded from attention, and by the thirteenth century only the general types ‘sweet’ and ‘sour’ were recognized by the writers of the day. However, interest revived, and by the the sixteenth century, they were extensively planted in Europe. European settlers took them to North America, where sweet cherries were favored in the Pacific west coast, and sour types for pies were favored in the east.
Cultivated cherries have a fairly narrow genetic base, especially the sour cherries, and the varieties within a particular group are all fairly similar to each other. In the sweet cherry, there are various ‘Heart’ types and ‘Bigarreau’ types, hearts being softer and juicier than the firmer Biggarreaus. Sour cherries are not so much sour as acid. ‘Morellos’ have colored juice, ‘Amarelles’ have colorless juice. The ‘Duke’ types are crosses between sweet and sour cherries.
Cherries have a relatively short season, a short shelf life, are liable to split in rain, can be wiped out by hail at the wrong time, are liable to be damaged by birds, bruise easily, and can be expensive to pick. No wonder fresh cherries tend to be expensive! But nothing else tastes like a cherry! Fresh cherries are a delightful treat in season, but best value may come from buying frozen or canned dark cherries for addition to fruit salads and meat patties.
At 10 mg per 100 grams of flesh, both fresh sweet cherries and fresh sour cherries rank as a good source of vitamin C. But even frozen sour cherries have useful amounts-5mg/100gram. When it comes to vitamin A, sour cherries are a standout – they have almost ten times (1,000 International Units per 100 grams) more vitamin A than sweet cherries (110 I.U. per 100 grams). There will almost certainly be differences between varieties – light colored varieties probably have less vitamin A and anthocyanins than dark skinned and fleshed varieties. 20 sour cherries contain 12-25 milligrams of active compounds called anthocyanins, which at that concentration were found to prevent oxidative damage about as well as the commercial antioxidants added to many foodstuffs to prevent rancidity. Curiously, the same dosage was also observed to have an anti-inflammatory effect. Interestingly, recent tests on the anti-oxidant effectiveness of various commercial fruit put fresh cherries at number seven in anti-oxidant effectiveness against damaging oxidative processes in cells. The research didn’t reveal if they were dark or light cherries.
Laboratory tests suggest some fruit may reduce the buildup of LDL (low-density lipoprotein) cholesterol, a contributor to heart disease, stroke and atherosclerosis. Sweet cherries were tested as having the third highest LDL inhibitory effect, of those species and varieties of fruits tested (it is likely dark cherries and sour cherries would test even higher).
Cherries have from about 60mg to 90mg per 100 grams fresh weight of of ‘polyphenols’ -substances in plants hypothesised to confer reduced cancer risk benefits. For perspective, of the data I have seen, one variety of plum analysed at 4mg/100grams fresh weight at the low end, and a particular variety of grape analysed at nearly 500mg per 100 grams fresh weight at the high end.
Feijoa Feijoa sellowiana
The Feijoas is native to Southern Brazil, Paraguay, and Uruguay. It is a member of the Myrtaceae family, and the related Syzigium genus is present in Africa; the Syzigium berries of one species, at least, are still collected for food. Wild feijoa fruits are quite variable in sugar content, acidity and size, but all are pulpy, and edible. Feijoas are a forest margin plant, and the fruits are most acceptable. Apart from being highly favored by fruit fly maggots in their native range (which cause them to drop prematurely and destroy the pulp) where edible fruit could be found, they would have been a favored food of the humans expanding down into South America in ancient times.
Feijoas are a good source of vitamin C. Six average sized fruits fill an adults daily vitamin C needs. They are also a good source of folate (B complex, folic acid), with one fruit delivering about 10% of an adults minimum daily needs.
Feijoa flesh (not pulp) tends to ‘go brown’ fairly quickly after being cut (the degree varying with the variety). Altho’ it has never been investigated, this may be an indication that the fruit is particularly high in phenols.
Fig Ficus carica
The fig is native to Southern Arabia. If our distant ancestors used a route across the mouth of the Red Sea (at the present Straits of Bab el Mandeb) they would have come upon trees of the wild fig. They would have recognized it immediately, for there are quite a few Ficus species in Africa that are edible. F. vogelii is a species of tropical Africa as well as eastern Southern Africa. It produces it’s small, yellow fruit in coastal forests, on dune lands, as well as swampy sites. There are the insipid yellowish green fruits of F. soldanella of Southern Africa, the small, reddish and “remarkably appetizing for a wild fig” fruits of F. stuhlmannii in Central and East Africa, the edible “when not insect infested” F. salicifolia, and many others.
Another species of fig, the ‘sycamore fig’, F. sycomorus, is grown in Egypt and the countries of the East Mediterranean. The pear-shaped fruit are sweet and slightly aromatic, but they are inferior to the common fig.
Domestication dates aren’t known; fig seeds have been found in bronze age settlements in the Mediterranean, but it’s impossible to say whether they were from wild or domestic trees.
Figs are very soft when they are ripe, so they are particularly difficult to market as a fresh fruit. Most of the fruit is dried.
Extracts from the fruits of F. sycomorus and another wild fig with even poorer fruit, F. benjamina, have shown both “significant antibacterial activity” as well as “possible antitumor activity”. The common fig has relatively high levels (.5% of dry weight) of a phytochemical class called ‘coumarins’. These compounds have been used in the treatment of prostate cancer, and one form of this phytochemical is being investigated for its activity against skin cancer. The other possibly anti-tumour compound is benzaldehyde, which has shown significant activity against cancers in at least one test tube study. These results may indicate a possible preventative effect at the level found naturally in the fruit.
Commercially dried figs (treated with sulfur dioxide and potassium sorbate) have one of the highest contents of ‘polyphenols’ -substances in plants hypothesised to confer reduced cancer risk benefits – of commonly consumed foods, at around 1,000mg per 100grams of dried fig. Only some seeds have similarly high amounts.
While it doesn’t rate as a source of vitamin C, figs have one of the highest amount of calcium of any common fruit (35 mg per 100 grams), and dried figs have genuinely useful amounts – 146 mg/100grams. (the RDA for calcium for an adult is 800 grams).
Grape Vitis vinifera, V. species
While I have been able to find no species of Vitis recorded in our ancestral African homeland, there are several species of the genus Rhoicissus in Africa which bears a strong resemblance to the grape, and are in the same family (Vitaceae). The fruit are deep purple, same size as grapes, and grow in forested lands. They are very acid, but native people eat them – although one account associated them with a case of “severe colic and diarrhea” in three children, with one subsequently dying.
The grape is native to mountainous Central Asia, the natural home of so many important fruits. So our ancestors would have run more or less straight into them as they radiated out of Africa. Wild grapes are generally good to eat, occurring as both black and white forms, with the black tending toward high acidity and low sugar, and the white the reverse. No doubt our ancestors made good use of the autumn harvest of these vines – especially as they may well have been climbing wild plum or wild pear trees. As the deciduous forests in the region were chopped down to make way for agriculture, the best vines – and the trees they grew on – were kept. The grape extends as far west as hills bordering the southern shores of the Black and Caspian seas; and it is probably from here that they spread west as humans became village people and started protecting and cultivating nice fruits. The grape had been domesticated in the western part of South West Asia for about 6,000 years before present. Cultivation reached Greece maybe around 3,000 years ago, and then was spread throughout the Mediterranean along the Phoenician sea routes. Vine culture went with the Romans throughout Europe, and monasteries in Europe become one of the repositories of knowledge of culture and varieties. The Spanish and Portuguese took the vine with them in all their colonization’s of North, Central, and South America.
North America is rich with Vitis species, and when the Asian grape was introduced in the seventeenth Century to the Atlantic seaboard, it set the scene for hybridization with native species, especially as the introduced species was subject to many diseases in it’s new country. Seedlings of these spontaneous hybridisations were appreciated as important having the disease resistance of the native ‘fox’, ‘muscadine’, and ‘riverbank’ grapes, and the superior sweetness and size of the Asian/European grape. The well known ‘Concord’ variety of grape is one example.
The Asian/European grape is now commercially grown throughout the world, with western Europe, the Balkans, California, Australia, South Africa, and Chile being major producers.
Grapes are pretty easy to eat, and by the time you have snacked on 100 grams (around a dozen grapes, depending on size), and adult will have satisfied about 18% of their recommended daily requirement of vitamin C. Grapes have long been known as a ‘health’ food, and it is thought they may contain useful amounts of antioxidant, protective, natural plant chemicals. It is likely that the most darkly colored (black) grapes will have the most protectant phytochemicals in them, although this has not been investigated (except for American ‘scuppernog’ muscadine grape species, where bronze and dark skinned varieties have been shown to be high in resveratrol). Resveratrol, a phenolic compound, is the best known protective compound in grapes, and it is particularly prevalent in darker skinned grape varieties. It is present in red wine, and some suggest that moderate red wine consumption is associated with a decrease in risk of coronary heart disease. Dark grape juice contains the same protective compounds. As do raisins. Recently, the molecular basis of how resveratrol has been worked out. It interferes with an unhelpful bodily process that prevents cancer cells being recognised and destroyed by the bodies natural defends.
“A couple of years ago, a group at the University of Illinois found that Resveratrol has both anti-inflammatory and anti-cancer properties…this is very exciting work because we believe it explains how diet modulates changes at the molecular level; it provides a molecular rationale for the broad chemo-preventive properties of trans-Resveratrol and by extention, grapes and grape products.”
– Dr. Minnie Holmes-McNary, UNC-CH School of Medicine’s Lineberger Comprehensive Cancer Center
Dried grapes (‘raisins’) were ranked second in scientific tests to identify the most antioxidant rich fruits and vegetables. On this basis, raisins have to be an excellent ‘protective-value-for-money’ choice.
Interestingly, recent tests on the anti-oxidant effectiveness of various commercial fruit put fresh red grapes at number six in anti-oxidant effectiveness against damaging oxidative processes in cells.
Nutritional analysis JJJ of commercial white and black grapes can be found at the Cape fruit website
Grapefruit Citrus paradisica
Citrus as a genus are not represented in Africa – although there is one obscure, very Citrus like member of the citrus family present, and that is Citropsis daweana. The Mozambique ‘Cherry Orange’ is a small tree of riverine valleys with citrus smelling leaves, and small, probably edible fruit. So when we radiated to South East Asia, the possible real origin of the grapefruit, we would have been meeting wild citrus not too different from Citropsis, except larger and more edible. Edibility is fairly widespread in the citrus as a group, with quite a few of the 35 or so species being a potential food item.
The commercial grapefruit arose in the eighteenth century in the West Indies. There is still some uncertainty whether it is a true species, or a hybrid of unknown origin, but probably of the South East Asian Pummelo, C. maxima, which it closely resembles.
The main grapefruit producing areas are southern and western United States.
Grapefruit are an excellent source of vitamin C, with an average serving dealing to two thirds of an adults daily minimum requirement.
Grapefruit juice contains citrus flavonoid compounds not in other citrus juices. The most prevalent flavonoid is naringin,
responsible for the characteristic bitter taste of grapefruit juice. Flavonoids in general have shown protective biochemical effects.
Grapefruit have natural plant chemicals (‘phytochemicals’) called ‘monoterpenes’ in their skin that both protect against cells becoming cancerous, and help fight existing cancers. At least, as studied in laboratory mice – but there is no reason to think these chemicals wouldn’t be active in humans. Unless they are certified as ‘organically grown’, commercial citrus may have been dipped/sprayed with anti fungal chemicals to prevent storage rots (they may also be dyed to heighten the color, and waxed with a vegetable derived wax to heighten the appearance). Therefore it is advisable to select only organic fruit to chew on the peel. It is unknown if the tumor fighting chemicals survive heat and processing when marmalade is made.
Guava, tropical Psidium guajava
Native to tropical America, from Mexico to Peru. Remains of guava have been identified in 2,800 year old human settlements in Peru, but whether domesticated or wild harvested is impossible to tell. There are said to be about 150 species of the genus Psidium, but only the ‘tropical’ guava has become a commercial crop – presumably because it is larger, and much firmer than most other species.
Spanish and Portuguese colonizers took the guava back to Europe with them, and then on to their colonies in Africa and South East Asia.
Tropical guavas are very subject to fruit fly infestation, which limits their production in some areas. Most fruit are consumed locally, as the fruit doesn’t have a long shelf life. Guavas are very variable in size, sweetness, skin and flesh color – in some respects it is suprising that they have not been selectively bred for better market characteristics. After all, from the nutritional point of view, they are a quite exceptional fruit.
The tropical guava is the most outstanding fruit for vitamin C content of any commercial fruit listed here. It has an exceptional 165mg of vitamin C per fruit – twice the amount of the second place holder, the kiwifruit – an exceptionally good source itself. Cooked guava products, in the form of ‘guava sauce’ (presumably cooked pulp), is also an exceptional vitamin C source, at 143mg/100 grams. According to the South African canning industry, some pink guava varieties have an astonishing 400 to 450 mg/100 gms of vitamin C!
One guava (90 gram size) supplies about 5% of an adults minimum daily Niacin (B3) needs. A guava of this size also has nearly 800 International Units of vitamin A, a very useful contribution to the daily requirement, and making it the sixth highest source amongst the fruits on this page. Tropical guavas are also high in Potassium, and an excellent source of dietary fiber.
There is one report that of guava fruit consumption results in reduced triglyceride levels in the blood (a risk indicator for heart disease) and reduced hypertension, while increasing the level of high density lipoprotein (‘good’) cholesterol.
Kiwifruit Actinidia deliciosa, A. chinensis, A. arguta
The kiwi is native to East Asia, where there are about 40 species of kiwifruit, some bland, some sweet, some ‘peppery’, some cherry sized, some the size of a smaller grade commercial fruit. These vigorous climbers fruit heavily, and we can be sure humans have used the fruit (that the birds, bears, and monkeys leave) for food from the time ancestral humans first moved into the kiwifruits’ range. People have always harvested these fruit, and in parts of Russia, at least, a cold hardy kiwi, Actinidia kolomikta, is still harvested from the coniferous forests.The amount of vitamin C varies between species, and also between individual plants in a species. Some of the most common wild kiwifruit, particularly Actinidia kolomikta, A. arguta, and A. chinensis, have spectacular amounts of vitamin C.
The commercialization of the green fleshed kiwifruit (A. deliciosa) was slow, in spite of it’s excellent keeping qualities and bruise resistance. British missionaries sent seed to a New Zealand nurseryman, who first fruited the plant in 1910. A selection said to be from this seedling population gave rise to the kiwifruit industry in New Zealand in the 1970’s and 80’s, and it’s success saw the commercial form spread to USA, Chile, South Africa, and parts of Europe.
New hybrids between the various species have been developed in France, Canada, USA, and New Zealand. As these become available, expect to see grape sized kiwifruit, red kiwifruit, yellow fleshed kiwifruit, and perhaps a kiwifruit with a vitamin C content even more magnificent than the present green ‘Hayward’ variety. This is because one wild species, A. eriantha, is said to have 1,000 milligrams of vitamin C per 100 grams of flesh. Unfortunately, A. eriantha is also not very palatable. A new yellow fleshed kiwifruit will be launched worlwide in the year 2000, and this fruit has around 100 mg vitamin C per fruit, which is quite exceptional.
Kiwifruit are one of the most ‘nutritionally dense’ foods – there is a higher concentration of vitamins and minerals per calorie than most other fruits. Most important of all, perhaps, one kiwifruit provides about 115 % of the USRDA for Vitamin C! Kiwifruit are an exceptional source of this vitamin. Vitamin C can greatly improve our bodies ability to absorb and use iron, and one kiwifruit has about 2% of the USRDA for iron.
One fruit also delivers around around 14% of an adults daily folate (B complex, folic acid) requirement. Given that the best sources of folate- green leafy vegetables – typically lose 50% of their folate in cooking, the folate of kiwifruit (usually eaten without cooking) is more valuable than it would first appear.
The potassium content is fourth highest of any domestic fruit (332mg per100grams). The calcium content of a kiwifruit, at 2.25% US Recommended Daily Allowance, is not particularly high, but it is higher than all but a few other fruits. The amount of the micronutrient chromium needed in human nutrition hasn’t been established (chromium has a role in heartbeat and carbohydrate use in the body. It may be one factor in avoiding diabetes and heart disease). Current tentative indications are that between 0.05 mg and 0.2 mg daily is required. One kiwifruit has, on average, 0.17 mg of chromium. This represents 35% of the daily need if it is set at 0.05mg, and 10% of the daily need if it is set at 0.2mg.. While kiwifruit are sometimes touted as having useful amounts of vitamin E, this is in the tiny seeds, which pass through the body undigested.
Interestingly, recent tests on the anti-oxidant effectiveness of various commercial fruit put fresh kiwifruit at number eight in anti-oxidant effectiveness against damaging oxidative processes in cells.
A kiwifruit has around 1.5 grams of ‘crude fiber’, and “several times” that amount of dietary fiber (gums, pectins etc.), which makes it an exceptionally good fiber source – fiber being important in bowel health, and in removing toxins in the intestines.
Lemon Citrus limon
The lemon developed from ancestral plants probably in South east Asia. The cultivated lemon is possibly a natural hybrid of two wild species, most likely lime, C. aurantifolia, and citron, C. medica. Some believe it arose solely from ancestral versions of C. medica. The first written mention of the lemon was in an Sanskrit writing in India from 2,800 years ago. It’s spread with agriculture and settlement was to the East, into south Asia, southwest Asia, and then to the eastern Mediterranean. Lemons went from the Middle East along the shipping routes to Spain and northern Africa in the Middle Ages. The Spanish and Portuguese soon introduced it to their colonies in South America and the Caribbean.
Lemons have natural plant chemicals (‘phytochemicals’) called ‘monoterpenes’ in their skin that both protect against cells becoming cancerous, and help fight existing cancers. At least, as studied in laboratory mice – but there is no reason to think these chemicals wouldn’t be active in humans. Unless they are certified as ‘organically grown’, commercial citrus may have been dipped/sprayed with anti fungal chemicals to prevent storage rots (they may also be dyed to heighten the color, and waxed with a vegetable derived wax to heighten the appearance). Therefore it is advisable to select only organic fruit to chew on the peel. It is unknown if the tumor fighting chemicals survive heat and processing when marmalade is made
Lime Citrus aurantifolia
The Limes developed from ancestral plants probably in Eastern India. It’s spread via human culture pretty much mirrors the lemon, except that it requires a marginally warmer climate. Limes and lemons are obviously not a fruit you would eat like an apple, but it says a great deal about flavoring food that we have valued this fruit for so long.
Limes have natural plant chemicals (‘phytochemicals’) called ‘monoterpenes’ in their skin that both protect against cells becoming cancerous, and help fight existing cancers. At least, as studied in laboratory mice – but there is no reason to think these chemicals wouldn’t be active in humans. Unless they are certified as ‘organically grown’, commercial citrus may have been dipped/sprayed with anti fungal chemicals to prevent storage rots (they may also be waxed with a vegetable derived wax to heighten the appearance). Therefore it is advisable to select only organic fruit to chew on the peel. It is unknown if the tumor fighting chemicals survive heat and processing when marmalade is made
Lychee Litchi chinensis
The Lychee is native to the warmer forests of Southern China and probably Vietnam. It has been cultivated in China for well over a thousand years, and would no doubt have been a keenly sought after forest fruit in subtropical Sino-Vietnamese Asia. However, the human stem population that remained in Africa had fruit in the same family (Sapindaceae) that were quite similar. Fruit of Zanha africana from central Africa has velvety yellowish small fruit with orange colored pleasant pulp. Zanha golungensis, also from central Africa, has edible, bright orange, smooth oval fruit borne in heavy profusion.
Lychees are so delightful it is hardly suprising they have been brought into cultivation. Unfortunately, they don’t have a startlingly long shelf life, and are relatively easily damaged in transport and handling. The trees themselves bear heavily when the conditions suit them, but they are notoriously demanding in climatic conditions. So they will always be a luxury fruit, except as a canned fruit. Lychees can be dried within their skin/shell. Sun or fire dried lychees are known as lychee-nuts and taste a bit like a raisin.
At 72mg of vitamin C per 100 grams of flesh, lychees are a very good source for this essential vitamin. Three lychee fruits would meet a third of an adults daily vitamin C requirement.
Mango Mangifera indica
The mango belongs to a group of species of large forest tree native to an area that stretches from northern eastern India down thru’ South East Asia to New Guinea. Several of the 40 or so species have fruits that are wild harvested (M. caesia, M. quadifera and M. pajang, in Borneo, for example) but only ‘the’ mango, M. indica, has become a domesticated plant.
Mango germplasm in the wild seriously endangered – a short article
Wild mangos have fruit that are very fibrous, with high concentrations of ‘turpentiney’ resin. Some, such as M. quadifera have strong unidentified ‘pungent’ chemicals in the flesh. Some wild species are large, others small, with varying shaped fruit. The low fiber, relatively small stoned and resin free fruit we have today is the result of millennia of human selection. Mango seedlings are highly variable, so there was good opportunity for better sorts to arise as agricultural settlement commenced.
Mangoes need a dry period during fruit set; they also need subtropical to tropical conditions without frost. Spread was therefore mainly to the east, into Myanmar (Burma), Vietnam, and south. It is suspected that Portuguese merchants or travelers took the mango from India to east Africa, West Africa, and then to their colonies in the Americas, probably in the sixteenth century. Mangoes were grown in the West Indies in the eighteen century, and Florida in the nineteenth.
Mangoes have a relatively short shelf life, but the advent of air freight has meant mangoes can be exported from tropical South East Asia, Mexico, India and Africa and arrive in Europe and North America in excellent condition. However, given the cost of air freight, and the lack of extended shelf life, mangoes will always tend toward the luxury end of the market (except in countries where they can be grown locally). Which is a pity, because they are a particularly useful human food.
Not only are mangoes an excellent source of vitamin C (one fruit pretty much fills an adults daily vitamin C requirement), they also have the highest concentration of vitamin A of any commercial fruit listed here (an excellent 3,894 International Units per 100 grams of flesh).
Melon, Cantaloupe Cucumis melo
The melon is, like ourselves, an African. There are quite a few species of the genus Cucumis in Africa, and the wild melon that humans eventually domesticated is a native of sub Saharan eastern tropical Africa. It is believed to have been domesticated fairly late, relative to other crops, but once domesticated many and variable forms arose. It succeeded best in the drier, longer season parts of India and South West Asia; in fact it naturalized in India, and India is regarded as a secondary center of wild germplasm. From South West Asia it spread to Greece and Italy, and all parts of the historic Mediterranean world. It captured the imagination of France not long after it reached there about the fifteenth century, where one intellectual produced a treatise enumerating fifty different ways of eating melons, including in soup, fritters, and served with salt and pepper! The English ‘aristocracy’ prided themselves on the perfect melons their gardeners produced in their glasshouses. From England and the content, the melon went to America and all the colonies of the ‘new world’.
Melons are reasonably priced and seasonably available in countries that span several climatic zones, such as Australia and the USA. While they don’t have a very long shelf life, varieties have been bred with reasonably robust rinds to handle long distant transit. The variety and complexity of flavors, sizes, flesh colors and textures makes the melon one of the most exciting and interesting fruits there is. It is also an important source of some nutrients.
High in Potassium, rock melons/canteloupes are an excellent source of vitamin A – they are the second best source (after mangoes) of all the fruit mentioned on this page, with a very respectable 3,224 International Units per 100 grams. In addition, normal serving meets about half an adults daily vitamin C requirements, making them a very good vitamin C source.
Orange Citrus sinensis
Citrus as a genus are not represented in Africa – although there is one obscure, very Citrus like member of the citrus family present, and that is Citropsis daweana. The Mozambique ‘Cherry Orange’ is a small tree of riverine valleys with citrus smelling leaves, and small, probably edible fruit. So when we radiated to South East Asia, thru Myanmar (Burma) and into Eastern India (the possible place of origin of the sweet orange), we would have been meeting wild citrus not too different from Citropsis, except larger and more edible. The wild ancestral form of the sweet orange hasn’t been found. Edibility is fairly widespread in the citrus as a group, with quite a few of the 35 or so species being a potential food item. But the sweet orange is one of the best. The first historical record of the orange is in Chinese writings from 4,400 years ago.
As with most citrus and other good things, the rise of agricultural settlement and both land and sea trading between Europe, the greater Mediterranean through South West and South Asia to China, resulted in the spread of the orange into all these areas. Small citrus groves and protected ‘orangeries’ of the ‘noble’ courts were well established in suitable European climates from at least 2,000 years ago. Spanish and Portuguese explorers carried the orange to the ‘new world’ colonies in the Caribbean Islands and South America in the fifteenth and sixteenth centuries. Late in the eighteenth century citrus culture was already established in Florida, and just introduced into California. The orange was introduced to Australia by the British colonizers in the nineteenth century, and from Australia to New Zealand shortly after.
Today, of course, orange growing is big business, and carried out on a vast scale. This means reasonably priced fruit for the consumer. Oranges travel well, can be cool stored to extend their availability, and some varieties store ‘on the tree’ in the orchard for quite a while, further extending the season. Most oranges are actually used to make orange juice and other products, with only about 20% of the USA crop, at least, going on the fresh market.
Research into orange growing continues, and one of the more interesting developments, from the nutritional point of view, is the increasing number of ‘blood’ oranges being grown. These have anthocyanins in the juice, giving a red look to the flesh. Although noone appears to have investigated the matter, it would be reasonable to suspect that they would have increased antioxidant value.
One orange will meet about 20% of an adults daily folate needs, as well as being an excellent source of vitamin C – one orange supplying just over the entire US recommended daily intake (60mg for an adult).
Oranges have natural plant chemicals (‘phytochemicals’) called ‘monoterpenes’ in their skin that both protect against cells becoming cancerous, and help fight existing cancers. At least, as studied in laboratory mice – but there is no reason to think these chemicals wouldn’t be active in humans. One monoterpene, d-limonene, comprises more than 90% of the oil in orange peel. Unless they are certified as ‘organically grown’, commercial citrus may have been dipped/sprayed with anti fungal chemicals to prevent storage rots (they may also be dyed to heighten the color, and waxed with a vegetable derived wax to heighten the appearance). Therefore it is advisable to select only organic fruit to chew on the peel. It is unknown if the tumor fighting chemicals survive heat and processing when marmalade is made
Recent tests on the anti-oxidant effectiveness of various commercial fruit put oranges at number five in effectiveness against damaging oxidative processes in cells.
Scientists have recently identified several bioflavonoids from citrus that inhibit certain cytochrome P450 enzymes. One cytochrome enzyme, P450 1B1, can activate cigarette smoke, pesticides and other substances ( ‘procarcinogens’) in the body to become carcinogens. Hesperetin, the most abundant bioflavonoid in the juice of oranges, has been found to inhibit P450 1B1 from metabolizing procarcinogens, significantly reducing the opportunity for them to be converted into carcinogens.
Papaya Carica papaya
While no members of the genus Carica are present in Africa, there are two species of the closely related genus Cylicomorpha, from central Africa. There is no information on whether or not it has edible fruit.
But Caricas definitely do. There are twenty two species of Papaya, of varying plant and fruit size and edibility. Several more cold hardy species, C. pubescens, C. stipulata and natural hybrids between the two, are used as food in South America. C. stipulata tends to be high in the protein digesting enzyme papain, which can cause irritation to the lips; C. pubescens has tough flesh that only yields to cooking (although the seeds are embedded in a soft sweet pulp). Most are canned in syrup these days. Other species are too small, too dry, too flavorless, have odd tastes, and so on. Only Carica papaya seems to have had the sweetness, flavor, and flesh tenderness to be avidly sought after by the indigenous peoples of South and Central Americas.
The ‘tropical papaya’ (called by the English and their colonial descendants ‘pawpaw’) was probably native to the tropical lowlands of eastern Central America. Botanists believe the ancestral fruits were small, probably only 50 or 100 grams or so, and that the present forms are due to millennia of human selection. It spread widely through tropical middle America, from Mexico to Panama. Being easily grown from seed, and having excellent eating qualities, it quickly spread with the Spanish and Portuguese colonizers to the Caribbean, Africa, India, and all places where the climate and soil would allow it to grow.
Papaya are liable to damage in handling, and have only a moderate shelf life. They are reasonably priced in local markets in the tropics, as they grow quickly and easily and produce heavily. Apart from countries with multiple climatic zones, they are otherwise something of a luxury fruit. As a human food, they are of excellent flavor and sweetness, and mix and match with tangy lime juice in a classic combination . And their nutrition value is high.
One serving of papaya will meet about 20% of an adults daily folate needs, and provides about 75% of an adults daily vitamin C needs, an excellent percentage for any food.
Passionfruit, PurplePassiflora edulis
The purple passionfruit is native to an area going from Southern Brazil to Northern Argentina. There are no Passiflora species indigenous to Africa. There are, however, in Asia. I have no information on the edibility or otherwise of the Asian species, but many of the 120 or so species of Passifloras are edible. Some have tiny fruit, some have quite soft leathery skin, one has a rind that can only be opened with a hammer, many are rather small, one, the size of a football, is too big. Even so, there are very nice flavored passionfruit with good handling characteristics, such as P. ligularis, that are never available commercially.
Although passionfruit are – or used to be – prolific fruiting common dooryard fruits in the countries whose climate allows them to grow and fruit, they are quite demanding as to climate and soil conditions. Consequently, the fruit appear on the market more or less as a luxury item.
Purple passionfruits have the third highest potassium level of any domestic fruit on these pages, at 348mg per100 grams.
They have useful amounts of vitamin A, at 700 International Units per 100 grams.
Peach Prunus persica
The ancestral Prunus species which gave rise to both the almond and the peach (they are closely related) was probably native to Central Asia. The peach evolved toward the east of central Asia, toward Western China. The wild peaches of China show enormous variability, with flat fruit, beaked fruit, round fruit, red skin, whites skin, and yellow or white flesh. Our ancestors radiating out of Africa into Central and Western Asia would probably found a much smaller fruit than the one we know today, but it would still be welcome as a summer treat in the hot, dry woodlands of the West Asian interior. Two other species, P. ferganensis of Central Asia and P. mira of West Asia also have edible fruit, but they are inferior to the peach (altho’ P. ferganensis has been domesticated in the former USSR).
With agriculture came domestication, and peaches have been cultivated in China for millennia. Almost all peach seedlings produce worthwhile fruit, and they don’t take long to come into bearing, so villagers selecting larger or better tasting fruit would soon have improved the fruit. Traders on the silk road took the peach from China to Kashmir and over the central Asian mountains to Iraq (known as Persia in early historic times). When it arrived in Persia and adjacent countries isn’t known, but it soon became naturalized there. It is mentioned in Egyptian records about 3,400 years ago, however, so it must have arrived some long time before then. The spread to Europe via South West Asia and the middle East was inevitable. The peach may have been introduced to Greece by Alexander the Great, after his epic wars in Central Asia. The Europeans thought the peach came from Persia, so named this fruit from China ‘persica’, which means ‘Persia’. From Europe, the peach. went to the new world with Spanish and Portuguese explorers and colonizers of the 16th to17th centuries. Interestingly, the Spanish introduced the peach to the Northern Florida/Georgia coast of the USA.
Peaches are a fairly ephemeral fruit of the summer season. They don’t keep well, have to be picked at exactly the right stage if they are to ripen ‘off the tree’ but not bruise in store, and so are worth the price being asked. Firmer fleshed, deep yellow varieties are grown for canning, and these represent excellent value.
One peach ( of around 100 gram size) supplies about 5% of an adults minimum daily Niacin (B3) needs. Fresh and canned peaches have about the same amount of vitamin A, with one medium sized peach having about 530 International Units.
Pear Pyrus communis
Pear species in general abounded in the woods and forests of Central and South West Asia as we came out of the Levantine coastal corridor into the wide, wide world of South West Asia and beyond, so genetically, we are well familiar with this fruit and it’s relatives. The ancestral pear, Pyrus communis, grows wild in the forests of parts of Central and South West Asia. The ‘European’ pears’ origin was therefore certainly in this general region, more or less, but it is not an unaltered descendant of P. communis. In the wild P. communis fruits, like most wild pear species, are barely edible – they are small, gritty, hard, astringent and sour. Other species, P. nivalis, the ‘snow pear’, and P. serotina, the ‘Asian pear’ are thought to have naturally crossed with P. communis to produce the early forms of the pear we know today. Other species may also have been involved, particularly P. ussuriensis. It was likely these natural hybrids that our ancestors and bears alike preferred. Of the 22 odd species of Pyrus, only the ‘European’ (actually ‘Central Asian’), the ‘Asian’ pear and the ‘Ussuri’ pear (P. ussuriensis) have been domesticated.
The pattern of selection and improvement is linked to sparing preferred trees as the forests were cut to make way for agriculture and herding; spreading of seed of selected trees in human manure; and, very recently, learning how to propagate individual plants by grafting twigs to seedlings grown for the purpose.
Pears from South West Asia spread with settlement and trade into Europe, probably fairly late, as they are not mentioned in the bible. They were highly regarded, both for wine making and as a fresh fruit – altho’ even as late as the seventeenth century some writers were claiming raw pears were poisonous! From Europe they went to England, then in the boats of the colonizers to the American eastern seaboard and Australasia.
Today, the people of the North Caucasus mountains still collect wild Pyrus fruit, in spite of having ready access to a range of domestic fruit. And, in an echo from our ancient past, no doubt fathers still show their children where ‘the best pear trees are’.
Pears, like their relative the apple, have a good storage life. Unlike an apple, you can’t pick up a fully colored, ripe, crisp pear and eat it. Pears have to ripen and soften – not too much, or they are floury. This, and the trees susceptibility to a particular bacterial disease, are the limiting factors in consumer acceptance and grower expansion.
Few fruit can match a perfumed, sweet, juicy and fine fleshed, almost buttery, pear. But this marriage of superior variety and exact point of ripeness is not always easy to find. New pears are being bred, using the ‘Asian pear’ as a parent. Hopefully, this will produce a fine fleshed, slightly crisp, perfumed and aromatic fruit that will be edible from the moment we select it from the supermarket display. We shall see.
Persimmon, OrientalDiospyros kaki
The genus Diospyros includes quite a few African plants, and a suprising number have reasonably edible fruit. D. lycoides is a small shrub of Central and Southern Africa with small reddish fruit and translucent flesh. The pulp is “faintly sweet and insipid”. Unlike D. mespiliformis, whose pulp is very sweet. It’s small purple or yellowy fruits are sometimes dried and stored by African tribespeople. D. mespiliformis is common in the gallery forests alongside rivers in Southern Africa. There is increasing evidence that the fruit, fish, and animal resources of such gallery forests constituted one of the major habitats that humans evolved in. D. mespiliformis may, therefore, have been one of our most longstanding dietary items. I have not seen any analysis of this fruit, but another wild Southern African Diospyros. D. dichrophylla, has about 40 mg/100grams of flesh (compare with domestic persimmon fruit, below) Not all wild African Diospyros are small – D. batocana is small apple sized, yellowy orange, with a very acid pulp. The fruit of D. chamaethamnus have already been mentioned. The tropical African D. kirkii has small, sweet mealy fleshed fruit in spring, and is considered by one writer as perhaps being worth domesticating.
Even when a portion of the human species started radiating out of our African homeland, we did not leave ‘persimmons’ behind. There are wild species from central to East Asia, and also down into South East Asia. One of these, D. roxburghii from the northern part of South East Asia and the southernmost part of Central Asia, was possibly the progenitor of D. kaki.
D. kaki has tannins in the flesh which are responsible for the ‘astringency’ ( an unpleasant ‘furry’ feeling in the mouth) of the unripe fruit. Most fruit have a lot of tannins, which do not reduce until the fruit is soft ripe – at which point it absolutely cannot be handled without damage. It is probably for this reason that the fruit was so long to come to the west, apart from it’s need for particular climatic conditions and slowness to fruit from seed. And it is also for this reason that people have seized upon any chance seedlings with less tannin in the flesh.
Some plants, such as peaches, are easy to grow from seed, almost always give a good fruit, and take only three or four years to come into bearing. These kind of fruits soon become widespread along the trade routes. Persimmons are the antithesis, which explains, in part, why reduced tannin fruit have been so slow to ‘arise’.
It wasn’t really until the American and British contact with Japan in the nineteenth century that nurseries in America and Australasia started to obtain varieties of persimmon. They are hard to propagate, the fruit are unfamiliar and difficult to handle, so they had a fairly sparse distribution even then. It is only with the twentieth century identification of types with tannin levels so low they can be eaten when ripe but still firm that the persimmon became a commercial proposition.
And that is where they are today. Persimmons are still climatically demanding, and even in the low tannin fruits, there needs to be a further reduction.
This ancient fruit, whose territory we shared in all the stages of our evolution and radiation, could undoubtedly be improved. Perhaps species from Africa may impart wider adaptation and even lower tannin levels. We will never know; as with all fruits of low commercial ‘penetration’, there is little effort to radically improve the fruit.
Persimmons are an excellent source of vitamin C, with from 25 to 52mg per 100 grams of flesh, depending on the variety. The most common commercial low tannin variety, ‘Fuyu’, has 52mg/100 grams. Interestingly, and similar to apples, persimmons have very high concentrations of ascorbic acid in the skin. ‘Fuyu’ peel, for example, has more than four times the already excellent amount in the flesh.
Lycopene, a carotenoid protective against prostate cancer, is present in some varieties in quite high concentrations, as it is primarily responsible for the bright red color of the skin. How much, if any, is in the flesh, is uncertain. Other varieties have no lycopene at all (the lycopene component of the caretonoids in persimmon fruits varies, depending on the variety, from 0 to 30%). While some very thin skinned home garden varieties can be eaten skin and all, most are peeled before eating. The redder the skin, the higher the lycopene. Commercially, it would be prudent to select ‘no spray’ or ‘organic’ fruit if you wanted to eat the skin as well.
Pineapple Ananus communis
“On the margins of the Campo wild pine-apples also grew in great quantity. The fruit was of the same shape as our cultivated kind, but much small, the size being that of a moderately large apple. We gathered several quite ripe; they were pleasant to the taste, of the true pine-apple flavour, but had an abundance of fully developed seeds, and only a small quantity of eatable pulp”
– Henry Bates, ‘The Naturalist on the Amazons’, 1879.
The pineapple is thought thought by some to be derived from Ananus species native to the tropical Parana-Paraguay basin. The possible wild progenitors, A. bracteatus, A. paraguazensis, and Pseudananas sp. of the tropical Amazon all have edible, but seedy fruit; the more probable wild ancestor, a wild form of A. communis itself, probably indigenous to much drier lowland South Americas forests, has not been found. And because most lowland South Americas forests have been destroyed, it will probably be extinct by now. The native people of the American tropics have grown pineapples by planting offshoots and crowns for a very long time. Propagules of this ‘fruit of kings’ were spread west and north from the tropical Amazon, if that is it’s area of origin. Regardless, related species are seedy, and the odd ‘mutant’ self fertile pineapple will have as many as 3,000 hard seeds. People aren’t stupid – they infinitely preferred the seedless form, and spread it preferentially. In fact, the indigenous peoples of South Americas had selected varieties with different flesh color, different acidity levels, and different flavors.
Maritime trading Indian tribes traded and raided South Americas west coast and river systems. The Carib Indians introduced the pineapple to their Islands in the sea now named after them. The first westerner to see the pineapple was Christopher Columbus, in 1493, at Guadeloupe, one of the Caribbean Islands. His expedition records that the Carib Indians had clearly hastily deserted their village in fear of these strange men, because, apart from vessels of human body parts, they had left behind the dessert of freshly gathered fruit – including the pineapple.
This strange and wondrous fruit was taken back to Spain, from whence it was re-distributed to all suitable Spanish colonies, chiefly in the Pacific.
The world’s first commercial plantation was set up in Oahu, Hawaii in 1885. Hawaii remained the world’s main producer of
pineapples until the 1960’s, when production relocated and expanded in the Philippines. Pineapples are produced in all climatically suitable countries, and South East Asia is the dominant producer.
Pineapples keep fairly well, and, because of mass production methods, are relatively cheap.
Most varieties are a good source of vitamin C with a typical serving having around 13mg (about 20% of the recommended daily intake for an adult). Canned pineapple loses about a third of it’s vitamin C content in processing, but still contains a useful amount. There is some varietal differences in vitamin C content – ‘Queen Victoria’ pineapple has about 24mg/100 grams, and the variety ‘Del Monte Gold™’ has about 53mg/100 grams, making this particular variety an excellent source of vitamin C.
Pineapples contain the enzyme ‘bromelain’. Bromelain tablets (extracted from the pineapple plant stems) are sold in health stores with claims they help combat heart disease, arthritis, and various other illnesses . Scientists testing the tablets on the incidence of mammary gland infection in cows (mastitis) found that on average, they reduced the number of white blood cells (a normal immune system response to chronic infection) by a third. How bromelain does it isn’t certain, but scientists suspect the enzyme interferes with the synthesis of inflammatory substances in the body, such as prostaglandins.
Plum Prunus sp.
There are two main kinds of plum – the European plum, Prunus domestica, generally oval, mellow and often intriguingly flavored fruit (it also includes the prune plums) and the Japanese plums, P. salicina, the main fresh plums of commerce. There is a third type, P. institia, a native of Western Asia, which includes the small, acid, purple damsons and the small yellow mirabelle plums. Neither of these are of any commercial importance.
The plums our ancestors most likely encountered as some left Africa for Central and then South West Asia was a small plum called the cherry plum or bullace, P. cerasifera, a reasonably edible fruit. Other wild plums in the region included P. spinosa, the sloe plum. This plum is pretty much inedible, being very astringent indeed. Our expansion into China found us amongst the wild P. salicina, the ‘Japanese’ plum (correctly, obviously, the ‘Chinese’ plum – it wasn’t introduced to Japan until around 400 years ago).
The advances in fruit quality went hand in hand with the rise of agriculture, as it has (but not always) with most fruit. the ‘Japanese’ plum has probably had the longest human attention; the ‘European’ plum, P. domestica, is a natural hybrid between the edible P. cerasifera and the largely inedible P. spinosa, and it is suspected to have only occurred in the last 2,000 years or so, probably (but perhaps not only) in the Caucasus Mountain region of South West Asia.
From the South of South West Asia it is a short hop to Mediterranean Europe. Accordingly, Spanish missionaries introduced the European plum to west coast North America, and British colonizers took it to the east coast. Similarly, the European plum was taken to temperate and warm temperate climate colonies within the British Empire.
The ‘Japanese’ plum was much slower to reach the west, somewhat curiously – although it does need warmer climatic conditions than the European plum. As the name suggests, it wasn’t until American and British contact with the previously closed society of Japan in the late nineteenth and early twentieth century that nurserymen in the west acquired plants of this ‘novel’ fruit.
The Japanese plums and their hybrids are somewhat susceptible to bacterial disease in humid climates, and this has limited their extensive culture to dry climate areas. Plums, along with peaches, are the archetypal ‘summer fruit’, and the firmer fleshed modern varieties have a good shelf life, store for a while, and handle quite well. Their season is all too short. Plums are good ‘fruit of the season’, and fresh or dried, a valuable contributor to the human animals diet.
Plums have useful levels of riboflavin (B2), with two (66 gram sized) plums providing about a sixteenth of an adults recommended minimum daily intake, and fairly good amounts of vitamin C.
Dried prune plums (‘prunes’) were ranked an outstanding first in tests to identify the most antioxidant rich fruits and vegetables. Studies have shown that fresh plums have the fourth highest chemical effectiveness in preventing oxidation in cells of any other commercial fruit. Most of this anti-oxidant activity is in the juicy portion.
Dried plums (prunes), like dried figs, contribute a useful amount of of calcium toward meeting the recommended daily requirement of 800 mgs.
Raspberry Rubus idaeus
There are several species of wild raspberry in our African evolutionary homeland. Rubus ludwigii, from Southern Africa, has small, white pleasant fruit, and R. rigidus, with it’s glossy purple-black berries, is common from central Africa to the Cape.
As we radiated out into the fruit and nut filled woodlands of South West Asia, we would have come upon the wild form of the red raspberry, R. idaeus (named after Mt.Ida in the Caucasus Mountains), as well as related wild fruits such as Rubus chamaemorus, R. arcticus, R. saxatilis of the forest tundra belt of North Asia. Raspberries are easy to propagate, as plants or seed. They would have been taken to Europe by traders and soldiers, and the Romans, in particular, played their part in spreading them far afield. The British improved the fruit in the middle ages, and like most fruits, plants were sent to it’s colonies, including America (in the late eighteenth century). The red raspberry was already present in America however. A variety of the Southwest Asian raspberry, Rubus idaeus variety strigosus is indigenous to eastern North America. The black raspberry Rubus occidentalis, is found only in North America, and it wasn’t domesticated until the 1800’s.
Raspberries have a very short shelf life, they are liable to damage in transport and handling, and the plant can be subject to quite a few diseases. When conditions are good, they are very productive, and well suited to ‘commoditization’ as a frozen or pulp product for use in other manufactured ‘foods’. Fresh market berries are consequently relatively expensive, and have a short season. Frozen berries may give best value for money.
Laboratory tests suggest some berries may reduce the buildup of LDL (low-density lipoprotein) cholesterol, a contributor to heart disease, stroke and atherosclerosis. Raspberries were tested as having the second highest LDL inhibitory effect. Interestingly, the anthocyanin content (believed to be a protective antioxidant) of raspberries increases in storage, thus increasing their antioxidant value over time.
Strawberry Fragaria ananassa
The forty or so species of strawberry are all more or less edible, and one of the most widespread, F. vesca, the wood strawberry, is found in North Africa. Wherever we roamed in the temperate zone, there were woodland and meadow strawberries to be found. The best of these were F. vesca, F. viridis, and F. moschata (hautbois or musk strawberry). No great improvement seems to have occurred in these species subsequent to the commencement of farming, and while all three species were domesticated to a greater or lesser degree, the strawberry that we know today did not exist.
It wasn’t until seeds of a North American species, F. virgininiana (long used by indigenous Indians) were sent to Europe in the sixteenth century that the stage was set for production of the modern strawberry. The ‘meadow strawberry’, as it was called, was no bigger than the existing cultivated forms of the European woodland strawberry, but had a different flavor and were a different color. Quite a few varieties were selected from this introduction, and they became quite well spread amongst gardens of the day. The Indians of Chile had domesticated another American species, F. chiloensis, and the Spanish, impressed with it’s size and eating quality, spread it to other parts of South America, and mentioned it in documents of the day. A Frenchman was stirred to introduce plants to France in 1714. These proved to be fruitless unless cross pollenized by either F. moschata or
F. virgininiana. The natural cross pollenizing eventually resulted in a chance seedling hybrid between chiloensis and virginiana. This new ‘Pine Strawberry’ (‘pine’ as in ‘pineapple’) was first described in 1759, and was the first ever modern strawberry. And from this beginning breeders have developed the large, firm, red varieties we buy in the shops.
Fruit in general are not good sources of the B vitamin pantothenic acid, with the conspicuous exception of avocados, but strawberries have useful amounts. Half a dozen strawberries will provide almost a third of an adults minimum daily requirement.
Strawberries have very good quantities of vitamin C; five strawberries provide better than half the daily requirement for an adult.
As with tomato consumption, regular strawberry consumption has been significantly associated in one study, at least, with reduced risk of prostate cancer. Strawberries do not contain lycopene (the active carotenoid in tomatoes), so an as yet unidentified natural plant chemical unique to strawberries is responsible for the protective effect.
Strawberries were ranked sixth overall in tests to identify the most antioxidant rich fruits and vegetables. Laboratory tests in another study re-inforce this, suggesting some berries may reduce the buildup of LDL (low-density lipoprotein) cholesterol, a contributor to heart disease, stroke and atherosclerosis. In this last mentioned study, strawberries were tested as having the fifth highest LDL inhibitory effect of all the berries investigated. Interestingly, further studies have shown that strawberries, while having the sixth highest anti-oxidant concentration, are THIRD in actual chemical effectiveness in preventing oxidation in cells. Most of this anti-oxidant activity is in the juicy portion. As with raspberries, the anthocyanin content (believed to be a protective antioxidant) of strawberries increases over time in storage, thus increasing their antioxidant value while on the shelf.
Tamarillo Cyphomandra betaceae
The tamarillo is a short lived small tree grown all along the Andes at 1000 to 3000 Meters altitude. It has been grown for so long by the native peoples that it’s natural range and actual place of origin is now unknown. C. betaceae does require relatively frost free, mild conditions, which has limited it’s spread. The approximately egg shaped fruit are usually yellow or orange, although the commercially available varieties are usually a red skinned form selected in New Zealand. There are several very closely related species found in the wild, and one, from Bolivia (although present in USDA and New Zealand) Cyphomandra maternum, is suspected to be the distant ancestor of this species. Both the tree and the fruit of C. maternum are almost identical to the tamarillo, except that the ripe fruit from the only C. maternum, population that has been examined so far are so laden with ‘hot’ chemicals that humans can’t eat them. Pigs, interestingly, eat them with aplomb. However, Cyphomandras are distant relatives of tomatoes, and they are quite variable. The tamarillo may once have been as inedible as C. maternum – in fact, some varieties have a very slight hint of the chemicals in C. maternum. Humans have a highly discriminating palate, and have always selected sweeter, more pleasant fruit, and millennia of human preference may well have been responsible for the palatable fruit we have today.
In fact, the first commercial tamarillo varieties lacked sweetness, had a tendency to acidity, and had dark orange flesh and darkest purple seeds pulp. Today, most commercial varieties have red or pinkish red skin, but orange or yellow flesh, orange or yellow seed pulp, and are (usually) sweeter.
Today, tamarillos are produced commercially for export by only a few countries – chiefly New Zealand. There is a small domestic market in New Zealand, Australia, India, and some South American countries. However, no country is actively developing new varieties (unusually for a crop plant, there is also no germplasm collection – anywhere in the world), and it is likely to remain a minor fruit in the supermarket, in spite of it’s potential. It is not helped by having relatively poor storage characteristics.
Altho’ I have seen no data, it would be reasonable to assume that tamarillos would have a good vitamin A content, and may have the same kind of health beneficial red and yellow plant pigments that tomatoes have. Some writers describe tamarillos as having a ‘very good’ vitamin C content, which is very likely; however, I have seen no figures. While it is likely to be high in antioxidants – especially the more acid red seeded kinds – it appears not to have been investigated for antioxidant content.
Citrus as a genus are not represented in Africa – although there is one obscure, very Citrus like member of the citrus family present, and that is Citropsis daweana. The Mozambique ‘Cherry Orange’ is a small tree with citrus smelling leaves, and small, probably edible fruit that grows in riverine valleys in Mozambique and Zimbabwe. So when we radiated to Myanmar (Burma), South East Asia, and southern China, the possible origin of the mandarin, we would have been meeting wild citrus not too different from Citropsis, except a bit larger and more edible. The wild ancestral form of the mandarin hasn’t been found; either that or the mandarin is ancestral to both the orange and mandarins.
Edibility is fairly widespread in the citrus as a group, with quite a few of the 35 or so species being a potential food item. But the mandarin is one of the best. As with most citrus and other good things, the rise of agricultural settlement and both land and sea trading between Europe, the greater Mediterranean through South West and South Asia to China, resulted in the spread of the mandarin into all these areas. In time, the mandarin was spread to Spanish, Portuguese, and- eventually – British colonies. The tangerine was introduced to Australia by the British colonizers in the nineteenth century, and from Australia to New Zealand shortly after.
Mandarins don’t travel quite as well as oranges, but they can be cool stored to extend their availability, and the complex hybrids now being produced have better storage and handling characteristics. Hybrids include tangelos (tangerine x grapefruit), tangors (tangerine x orange), and tangtangelos (tangerine x tangelo). Mandarin hybrids, in particular, look set to become a standard market fruit, and excellent nutritional value.
Tangerines are a good source of vitamin A – in fact, they rank number 5 in the list of top sources from commercial fruit, with 920 International Units per 100 grams. They are a very good source of vitamin C – one fruit provides almost half an adults daily requirement.
Tangerines have natural plant chemicals (‘phytochemicals’) called ‘monoterpenes’ in their skin that both protect against cells becoming cancerous, and help fight existing cancers. At least, as studied in laboratory mice – but there is no reason to think these chemicals wouldn’t be active in humans. Unless they are certified as ‘organically grown’, commercial citrus may have been dipped/sprayed with anti fungal chemicals to prevent storage rots (they may also be dyed to heighten the color, and waxed with a vegetable derived wax to heighten the appearance). Therefore it is advisable to select only organic fruit to chew on the peel. It is unknown if the tumor fighting chemicals survive heat and processing when marmalade is made.
Watermelon Citrullus lanatus
The watermelon is native to the Kalahari desert of Southern Africa. One form of the fruit is bitter, due to the presence of a glucoside called ‘cucurbbitacin’. The other form lacks this bitter chemical, and is the progenitor of all domesticated watermelons. Kalahari tribesmen grind the seed for bread, they dry the flesh, and eat the young fruit as a vegetable. The wild form is quite large, crisp and juicy, but it is also tasteless.
Millennia of association with humans and their agriculture has selected for the sweet fruit we know today.
Watermelon is a very good source of vitamin C, with a typical serving supplying an adult with just on half their daily vitamin C requirement.
Wang H, Cao G, Prior RL.1996. ‘Total antioxidant capacity of fruits’.
J Agric Food Chem 1996; 44:701-5.
Joseph, J.A., Shukitt-Hale B., Denisova, N.A. Bielinski D., Martin, A., McEwen, J.J., & Bickford, P.C. 1999 “Reversal of age-related declines in the neuronal signal transduction, cognitive, and motor behavioral deficits with blueberry, spinach, or strawberry dietary supplementation.”
Journal of Neuroscience, September 15, 1999, Vol. 19, No. 18. pages 8114-8121.
Vinson, J. A., Hao, Y., and Zubik, L. 1998 ‘Phenol antioxidant quantity and quality in foods: vegetables.’
J. Agric. Food Chem. 46:3630, l998.
(includes analysis of commercially dried/treated figs)