Ohla, one of whose current positions is director of research and development at the Switzerland-headquartered fragrance and taste company Firmenich, says she “always found Brussels sprouts unbearably bitter”.

But since she constantly heard they were highly nutritious, she experimented to see if she could get used to their taste.

One of many findings by taste researchers like Ohla and Maik Behrens, head of the working group on taste and odour systems reception at the Leibniz Institute for Food Systems Biology at the Technical University of Munich in Germany, is that food preferences can change.

What doesn’t change, however, is whether foods such as Brussels sprouts and broccoli taste very bitter to you. This is inherited.

“Detection of certain bitter compounds has a genetic basis,” Behrens says, namely the TAS2R38 gene. People who carry the gene in a fully functional form – “most people do” – can intensely taste these compounds. But about 30 per cent of the population are “non-tasters”.

Another peculiarity of the sensation of bitterness is on our tongue. The papillae, the small rounded protuberances on its upper surface, contain taste buds with 25 different kinds of bitter taste receptors. For the other basic tastes – sweet, sour, salty and umami (savoury) – there are typically just one or two.

Contrary to what you may think, “hot” or “spicy” isn’t a taste, as the sensation doesn’t arise from our taste buds.

“It actually comes from stimulation of nerve endings (for touch, temperature and pain) in the oral cavity,” Behrens says. “Spicy isn’t a taste, but a pain or temperature sensation,” adds Ohla.

Much to the researchers’ frustration, there’s a stubbornly persistent notion that receptors for the various tastes are located in particular areas of the tongue: sweet in the front, sour and salty on the sides and bitter at the back.

“This is in fact nonsense,” Ohla says. The taste receptors are actually dispersed all over the tongue, with an especially large number of bitter taste receptors at the back.

“This makes sense,” explains Ohla, because stimulating this area also stimulates a nerve that can trigger the gag reflex, a protective response to prevent foreign objects from entering the throat and to expel inedible or toxic substances.

“Everything that activates the taste buds is relayed via nerves to the brain, where a taste sensation is then formed,” Behrens says. In common parlance, many senses are involved in taste, he notes, adding that “not without reason do we say that we eat with our eyes first”.

The sense of smell plays a greater role, though. Odours emanating from the oral cavity during eating and drinking pass through the upper part of the throat and are picked up by smell receptors in the nasal passages, contributing to the flavour of foods and drinks.

As she explains, the main reason for the former isn’t a difference in the taste receptors on their tongue, but a variation in a group of olfactory-receptor genes that allows them to strongly perceive soapy-flavoured organic compounds in the leaves.

Besides genetics, the extent of a person’s exposure to certain foods affects taste perceptions.

“Socialisation plays a role in food preferences too,” says Behrens. “In Asian countries, for example, where coriander is much more commonly used, there are far fewer people who reject it than do here [in Europe].”

“You can get used to almost anything,” remarks Ohla. “Psychology can override genetics.”

Her self-experiment with Brussels sprouts was a success. “It was really bad the first few days,” she recalls. “But now it’s one of my favourite vegetables.”