Should we be crying with joy at t
he arrival of tearless onions? A new variety known as Sunions, guaranteed to keep us dry-eyed when chopped, will go on sale in UK soon. Hailed by some as a culinary game changer, I shed a little inward tear of frustration at the news. Why? Because it’s important to cry when you chop onions – and let me explain why.

Sunions were launched in the US four years ago after decades of research and development. As the brand’s website explains, the volatile compounds responsible for the pungent flavour and teariness in standard onions remain the same or increase over time. But in Sunions, these compounds do the opposite and grow sweeter by the day.

Robert Oldershaw, director of the Oldershaw Group, the Lincolnshire-based company supplying Waitrose with Sunions, has said that the new variety rated low on the pyruvate scale, which measures pungency. “But if it’s not pungent, it’s not an onion, is it?” he was asked. “Well, you’ve still got that onion flavour,” Oldershaw countered.

I’m not convinced. The compound that causes us to well up when we chop onions, and the one responsible for the burning sensation when we eat them raw, is propanethial-S-oxide (PSO). Research shows that when you heat chopped onions, PSO turns into a new compound called 3-Mercapto-2-methylpentan-1-ol (MMP). This compound tastes deeply savoury, like meat broth, which is why chopped onions cooked low and slow provide that vital flavour base that make many dishes so delicious.

“The pungent molecules formed when you chop an onion, break down into meaty aroma molecules,” says Nik Sharma, a molecular biologist, cook and author of The Flavour Equation. In other words, if you remove the pungency in onions, you also remove flavour.

The tearless onion is just the latest chapter in the long-running ‘blandification’ and ‘sweetification’ of our food. Like most food writers – and many consumers – I’ve noticed that increasing numbers of ingredients have lost their bite and are missing the vibrant flavours for which we once prized them. Varieties of grapefruit sold in supermarkets, for example, no longer have that mouth-puckering bitterness. So-called ‘easy peelers’ mostly deliver tasteless disappointment rather than a citrus punch. Cucumbers are watery and insipid; tomatoes either taste of nothing or are just sweet.

In his 2015 book The Dorito Effect, Mark Schatzker argues that for almost 100 years, industrialised food production and intensive farming methods have focused on yield, pest resistance and appearance, at the expense of flavour. “The food we eat today still seems like food, but it tastes very different than it used to,” noted Schatzker.

Bitterness, in particular, is one flavour disappearing from our dinner tables. “It’s being bred out of many foods like grapefruit and aubergine,” says Jennifer McLagan, the award-winning author of Bitter. “I grew up on white, bitter grapefruit, but they are almost impossible to find, replaced by sweet pink ones, which are much less interesting to eat. Most lettuces began life as bitter weeds and celery was once the bitter plant called smallage.”

Chefs love cooking with strong robust flavours; bitterness, acidity, sourness, and other pungent notes deployed in the right balance can make your taste buds dance. Even fruit that’s supposed to be sweet – tomatoes, for example – are best when they have some sharpness and acidity, too. Foods without bitterness, pungency or acidity lack depth and complexity.

It is true that such flavours don’t appeal to everyone. some don’t like radicchio – the bitter leaves from northern Italy, for instance.

Although humans are naturally wired to love sweet flavours – breast milk is sweet, after all – the rise of ultra-processed foods, often laden with added sugar, has contributed to our ever-growing cravings. Fruit and vegetable growers have responded to meet demand. Seedless Grapes have been deliberately bred to taste like the fun fair confection. Red delicious apples are widely acknowledged to be bland. And aubergines no longer need salting and draining prior to cooking because the bitterness this process is intended to eliminate has been completely bred out of them.

Does any of this matter? Is the nuance of flavour something only foodies and chefs need to concern themselves with? Does it matter if onions are sweet? The answer is yes, because flavour often delivers nutrients. McLagan explains that grapefruit’s bitterness comes from a flavonoid (or plant compound) called naringin; a powerful antioxidant. “But what remains of this bitter-tasting chemical in grapefruit is [being] filtered out of grapefruit juice,” she says.

Compounds called glucosinolates, which impart bitterness in cruciferous vegetables (broccoli, Brussels sprouts, cabbage, kale, and rocket), are also responsible for their health benefits. These include improving the liver’s ability to process toxins, encouraging the growth of healthy gut bacteria, aiding digestion – and quelling cravings for sweets.

It’s true that science can play a valuable role in developing new varieties of fruits and vegetables. “I suspect down the road, we will move into more genetic engineering to be able to feed larger populations and provide as many nutrients as possible,” says Sharma. But flavour should not be left out of the equation. Shedding a tear or two while chopping an onion is surely a small price to pay for something that not only tastes delicious, but is good for us too.

Ingredients with a bitter bite

Rocket: These peppery leaves make a punchy addition to salads. Mix them with other milder leaves if you find them too strong. (Rocket also works well with other ingredients that tame its harshness). Whizz the leaves into a pesto with herbs including basil and parsley, or use as a garnish for pizza and pasta.

Radicchio: This Italian relative of chicory has purple and white leaves with a pronounced bitter flavour. It’s mainly used in salads but the leaves are fantastic cooked on a griddle. Try countering the bitterness with a dressing spiked with a spoonful of honey. The leaves also pair well with sweet vegetables such as roast squash or pumpkin.

The Daily Telegraph

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