Taste buds are just one reason why we love some foods and hate others.
Hot Chocolate. Doughnuts. Haribo’s. McDonald’s. The world is full of polarizing flavours and foods, beloved by many, despised by just as many. Why is that? Scientists have untangled some — but not nearly all — of the mysteries behind our love and hatred of certain foods. While we might say, “That tastes like strawberries”, food scientists would disagree. Our tongues perceive only five basic tastes: sweet, sour, bitter, salty and “umami,” the Japanese word for savoury. To go from merely sweet to “Mm, strawberry!” the nose needs to get involved. The taste and olfactory senses, along with any chemical irritation a food creates in the throat (think mint, hot pepper or olive oil), all send the brain the information it needs to distinguish flavours.
“We as primates are born liking sweet and disliking bitter,” said Marcia Pelchat, who studies food preferences at the Monell Chemical Senses Center in Philadelphia. The theory is that we are hard-wired to like and dislike certain basic tastes so that the mouth can act as the body’s gatekeeper.
Sweet means energy; sour means not ripe yet. Savoury means food may contain protein. Bitter means caution as many poisons are bitter. Salty means sodium, a necessary ingredient for several functions in our bodies. (By the way, those tongue maps that show taste buds clumped into zones that detect sweet, bitter, etc.? Very misleading. Taste receptors of all types blanket our tongues — except for the centre line — and some reside elsewhere in our mouths and throats.)
Researchers have found only one major human gene that detects sweet tastes, but we all have it. By contrast, 25 or more bitter receptor genes might exist, but combinations vary by person. Some genetic connections are so strong that scientists can accurately predict how people will react to certain bitter tastes by looking at their DNA. Research has also shown that we are predisposed to like flavours of foods our mothers ate while pregnant. These flavours are passed through amniotic fluids and later through breast milk, possibly signalling to the baby that if Mom ate it, it must be readily available and safe.
You simply cannot teach a rat or dog to like spicy food; scientists have tried. But in humans, it is easy. Culture often overrides our genes and takes over the mouth’s role as the body’s gatekeeper. Few people immediately like bitter beverages or extreme spices, but many learn to love them through repeated exposure. We often learn to like what people around us like. Some people can’t stand slimy, gritty or creamy foods, regardless of the flavour. Science cannot fully explain where texture issues come from, but a study released last fall by the Monell Chemical Senses Center offers a clue: People with more of a certain enzyme in their bodies tolerated the feel of thick, starchy foods better. Also, texture can affect flavour by altering the release of aroma molecules in the mouth. Manufacturers pay special attention to this when trying to make a low-fat substitute taste and feel like a high-fat food.
Have you got leftover jellybeans? Take this test to see if you can tell the difference between taste and flavour. (You might need to get Jelly Belly’s Bean Boozled pack of jellybeans to get the less conventional flavours).
• Get one jellybean in each of these very different flavours: banana, black liquorice and cappuccino.
• Now hold your nose. Without looking, pop one of the beans into your mouth and chew it, keeping your nostrils closed.
• Try to identify the flavour.
Very few people will be correct more than a third of the time just by guessing. Why? Because all three-taste sweet and a little bitter, our tongues cannot tell the difference.
• Let go of your nose. Suddenly you can easily distinguish the flavour. (This explains why food does not taste right when you have a stuffy nose.)
How interesting…. we are all born with a love of sweet foods and a dislike of bitter flavours, but beyond that, the foods we grow up to love can vary wildly.