Scientists have found that coffee both regular and decaffeinated, it increases the sensitivity and reduces to the sweet — to bitter. Those who drink coffee on a daily basis, worse still detect a bitter taste. Previously, it was believed that the effect of coffee on taste perception mediates caffeine and after bitter compounds sensitivity to sweet, on the contrary, becomes lower. Article published in the journal of Food.
Before you eat the food, we appreciate it with all my senses. It helps the body to recognize spoiled food and balance nutrition. For example, the bitter taste causes rejection and reduces the sensitivity to sweet. Evolutionary it is necessary to avoid toxic substances. However, some bitter foods have become popular in the diet of people. The most striking example is coffee.
Coffee has a clearly pronounced specific taste and smell and can affect the sensitivity to other chemical stimuli. Caffeine is associated with adenozinovmi receptor neurons and can change the perception of taste. It also blocks one of the receptors in the perception of sweet. Perfume shops, for example, even offer their customers to smell coffee to better distinguish the flavors, but the researchers are unable to prove the effect of coffee on the nose.
Alexander Fjelstad (Alexander Fjaeldstad) and Enrique Fernandez (Henrique Fernandes) from the Institute of taste Aarhus University have tested whether changes coffee taste and olfactory sensitivity. 156 participants consistently passed the test of taste and smell: they tried or smelled the solutions of different concentrations, starting with the smallest. The concentration at which the participant was able to distinguish the substance, was considered the threshold. To check the olfaction we used the solution of n-butanol to propylene glycol and 4 basic tastes were represented by solutions of sugar, citric acid, salt and quinine.
After the test volunteers drank a Cup of espresso from capsules and after two minutes again tried the same solutions. Third of the participants drank decaffeinated coffee.
Both drinks (with caffeine or without) increased the sensitivity to sweet and reduced — to the bitter (p < 0.001). This means that the participants recognize low concentrations of sugar solution, and feel the quinine, it was more difficult. People who drink coffee every day, sensitivity to bitter was still lower (p < 0.05). The sense of smell and the perception of salty and sour coffee is not affected.