Fruits and fructose: 75 foods rated

Apple is the reference case for excess fructose: it carries roughly twice as much fructose as glucose, and it is the ratio that decides, not the total. Glucose ferries fructose across the gut wall, so a fruit that runs short of glucose leaves fructose behind to ferment. Muir names it in the measurement rather than by reputation: apple, pear, mango, clingstone peach and watermelon were the five that came out with fructose in excess of glucose across 41 fruits analysed by HPLC-ELSD. Being on that list of five is what this level means. The sugars here were separated and measured rather than looked up: across the four fruits in that study - peach, apple, watermelon and cherry - fructose ran 5.79 to 104.01 mg per gram, glucose 9.25 to 99.62 and sucrose 15.82 to 106.39. Those are RANGES across four fruits, not a value for this one, which is the honest limit of what an abstract gives.

• Muir J et al., J Agric Food Chem 57 (2009) 554-565, short-chain carbohydrates measured by HPLC-ELSD in 45 vegetables and 41 fruits
• Ma C. et al., Food Chem 145 (2014) 784-788, fructose, sorbitol, glucose and sucrose in fruits by HPLC-ELSD

Fresh fig runs fructose-dominant, and the fruit is eaten whole and quickly - two or three figs is an easy portion and already past what most people absorb.

Guava carries excess fructose and a lot of it - the fruit is unusually sugary for its size. Juiced or made into paste it concentrates further, and the fibre that would have slowed it is gone.

Mango is fructose-dominant, and ripeness makes it more so - starch converts to sugar as it softens. A firm mango is easier than a soft one, which is the opposite of how most people choose them. Muir names the mango among five fruits of 41 measured with more fructose than glucose, which is what this axis turns on rather than total sugar.

• Muir J. et al., J Agric Food Chem 57 (2009) 554-565, short-chain carbohydrates in 45 vegetables and 41 fruits

Pear carries more fructose than glucose and adds sorbitol on top - two poorly absorbed sugars in one fruit. That combination is why pear is usually the first thing removed and the last thing reintroduced. Muir puts the pear among the five fruits of 41 with fructose in excess of glucose; the same study measured sorbitol in fifteen fruits at 0.53 to 5.99 grams per hundred without saying which fifteen. Two mechanisms in one fruit is why it sits where it does.

• Muir J et al., J Agric Food Chem 57 (2009) 554-565, short-chain carbohydrates measured by HPLC-ELSD in 45 vegetables and 41 fruits

Watermelon is mostly water, which misleads people - but what sugar it has runs fructose-heavy, and nobody eats a small portion of watermelon. The volume is the problem, not the concentration. The sugars here were separated and measured rather than looked up: across the four fruits in that study - peach, apple, watermelon and cherry - fructose ran 5.79 to 104.01 mg per gram, glucose 9.25 to 99.62 and sucrose 15.82 to 106.39. Those are RANGES across four fruits, not a value for this one, which is the honest limit of what an abstract gives. Muir names the watermelon among five fruits of 41 measured with more fructose than glucose; the study publishes no figure for it, only that it belongs to that group.

• Ma C. et al., Food Chem 145 (2014) 784-788, fructose, sorbitol, glucose and sucrose in fruits by HPLC-ELSD
• Muir J. et al., J Agric Food Chem 57 (2009) 554-565, short-chain carbohydrates in 45 vegetables and 41 fruits

Blackcurrant carries excess fructose, and it is rarely eaten fresh - it arrives as coulis, syrup or jam, where the sugar is concentrated and more is added on top.

A dried peach concentrates what the fresh one carries, and Muir measured the peach as carrying more fructose than glucose. Drying removes water and not sugar, so the dried form cannot sit below the fresh one — that part is a derivation rather than a second measurement, and it is worth saying so.

• Muir J.G. et al., J Agric Food Chem 55 (2007) 6619–27 and 57 (2009) 554–65, fructans and short-chain carbohydrates measured in Australian vegetables and fruit

Jackfruit is fructose-dominant but eaten in pieces rather than whole, and the unripe fruit used as a meat substitute is a different thing again - it is starchy and barely sweet.

The longan is a sweet tropical fruit, and sweetness on this axis is a question of the fructose-glucose balance rather than of total sugar — a balance not measured for it.

Peach is one of the five fruits Muir measured as carrying more fructose than glucose, alongside apple, pear, mango and watermelon. The paper publishes no figure for the peach, and it names the CLINGSTONE peach specifically, where this covers every kind. The sorbitol is the other half of the answer, and it is the heavier half. The sugars here were separated and measured rather than looked up: across the four fruits in that study - peach, apple, watermelon and cherry - fructose ran 5.79 to 104.01 mg per gram, glucose 9.25 to 99.62 and sucrose 15.82 to 106.39. Those are RANGES across four fruits, not a value for this one, which is the honest limit of what an abstract gives.

• Muir J.G. et al., J Agric Food Chem 55 (2007) 6619–27 and 57 (2009) 554–65, fructans and short-chain carbohydrates measured in Australian vegetables and fruit
• Ma C. et al., Food Chem 145 (2014) 784-788, fructose, sorbitol, glucose and sucrose in fruits by HPLC-ELSD

Persimmon is fructose-bearing and gets sweeter as it ripens to the point of collapse - the astringent stage that precedes it is lower in free sugar as well as unpleasant.

Sun-dried tomato concentrates the fruit's fructose several times over as the water leaves. Tomato is mild fresh; dried it is a different order, though the portion is small.

• USDA FoodData Central, the national nutrient database, queried for the sugar profile

Tamarind pulp is fructose-bearing and intensely sour, which hides how sugary it is - the acidity masks the sweetness rather than replacing it.

Acorn squash is starchy rather than sugary, and its fructose is balanced by glucose. Roasting caramelises some starch into sugar, which changes the taste more than the ratio.

Canned apricots sit lower than fresh ones for a mechanical reason: the syrup they are packed in is usually sucrose or glucose, which adds glucose to the fruit's own fructose and helps rather than hinders.

Banana is low on this axis because of glucose and fructose in step, and the starch that has not yet converted. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

Bell pepper is botanically a fruit and carries a little fructose, balanced by glucose. Red peppers are riper and sweeter than green, but neither reaches a level that matters.

Blood orange: what matters on this axis is not how much fructose a fruit holds but whether it holds more fructose than glucose, because glucose carries fructose across the gut wall with it. An orange is close to even, which is why it sits low here while fruits with the same sugar content sit high. The blood orange is an orange in this respect as in every other.

Blueberry is low on this axis because of glucose slightly ahead of fructose. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

Cantaloupe is low on this axis because of sucrose first, then glucose and fructose in balance. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

Cherry carries fructose. It was one of four fruits measured by HPLC, and fructose was found in all four, from 5.79 to 104.01 mg per gram. The abstract gives that range across the four and no value for any single one.

• Ma C. et al., Food Chem 145 (2014) 784-788, fructose, sorbitol, glucose and sucrose in fruits by HPLC-ELSD

Glucose and fructose are the dominant sugars of chokeberry, as they are of berries generally, and neither is in excess of the other — which is what this axis counts.

• Mikulic-Petkovsek M et al., J Food Sci 77:10 (2012) C1064-C1070, sugars, organic acids and total phenolics in 25 berry species

Cranberry is low on this axis because of more glucose than fructose, unusually for a berry. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

Dragon fruit is low on this axis because of little total sugar and no fructose excess. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

Dried apricots concentrate the fruit but the apricot is glucose-balanced to begin with, so concentrating it does not create a fructose excess. The sulphites used to keep them orange are a separate question.

Glucose and fructose are the dominant sugars of elderberry, as they are of berries generally, and neither is in excess of the other.

• Mikulic-Petkovsek M et al., J Food Sci 77:10 (2012) C1064-C1070, sugars, organic acids and total phenolics in 25 berry species

Galia melon is low on this axis because of the same balanced profile as the other melons. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

Kiwi carries free fructose, though less of it than its sweetness suggests: a measurement of the kiwi's sugars put sucrose at 71.9 per cent of the total, which leaves glucose and fructose to share roughly the remaining quarter between them. Sucrose is itself a glucose joined to a fructose and is split into the two during digestion, so what a kiwi finally delivers is more than its free fructose alone. A ripe kiwi is sweeter than a firm one for the same reason any fruit is, so the state it is eaten in moves the figure.

• Mikulic-Petkovsek M. et al., Journal of Food Science 77 (2012) C1064–C1070 — the share of sucrose in the kiwi's total sugars, with no milligram figure per 100 g for fructose or for any other sugar

The lingonberry is a berry, and berries carry free fructose, but no analysis of this one is published.

Mulberry is low on this axis because of glucose keeping pace with fructose. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

Orange is low on this axis because of balanced sugars, with sucrose making up much of the total. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

Passion fruit is low on this axis because of small seeds and pulp, with the sugars roughly matched. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

Pineapple is low on this axis because of sucrose-dominant rather than fructose-dominant. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

Plantain is low on this axis because of mostly starch rather than sugar until it blackens. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.

The syrup is where most people meet the rose hip, and a syrup concentrates whatever fructose the fruit had.

Strawberry is low on this axis because of an even split of the two sugars. Fructose only causes trouble when it outruns glucose - glucose is what carries it across the gut wall, so a balanced fruit is absorbed even when it tastes sweet.