Taste and temperature

Some people like food or beverages hot and some like them cold. What's the difference? Can the temperature of the food we eat affect the intensity of its taste? It depends on the taste, according to a new study by Dr. Gary Pickering and colleagues from Brock University in Canada. Their work shows that changes in the temperature of foods and drinks have an effect on the intensity of sour, bitter and astringent tastes but not sweetness. Their work is published online in Springer's Chemosensory Perception journal. Humans receive tastes through sensory organs called taste buds concentrated on the top of the tongue. Taste is sensed through taste cells, which are known as taste buds. There are about 100,000 taste buds that are located on the back and front of the tongue. Others are located on the roof, sides and back of the mouth, and in the throat. Temperature can be an essential element of the taste experience. Food and drink that in a given culture is traditionally served hot is often considered distasteful if cold, and vice versa. For example, alcoholic beverages, with a few exceptions, are usually thought best when served cold, but soups—again, with exceptions—are usually only eaten hot. A cultural example is soda. In North America it is almost always preferred cold, regardless of season. In South America lukewarm soda is almost exclusively consumed in winter. We are all familiar with the effect of temperature on taste - think about starting to eat or drink something while it is warm and finishing when it has cooled, or vice versa. The same food or beverage can taste different depending on its temperature. In addition, in 20-30 percent of the population, heating or cooling small areas of the tongue draws out a taste sensation without the presence of food or drink.   Over three study sessions, 74 participants recruited from Brock University and the local community (a combination of thermal tasters, super tasters i.e. people who are particularly sensitive to tastes in general, and regular tasters) tasted sweet, sour, bitter and astringent solutions at both 5 C and 35 C. They were then asked to rate the intensity of the tastes over a period of time. For all three types of tasters, temperature influenced the maximum perceived intensity from astringent, bitter and sour solutions, but not from the sweet solutions. Specifically: Astringency was more intense when the solution was warm, and the intensity of the flavor lasted longer with the warm solution than with the cold one Bitterness was more intense with the cold solution and the flavor intensity declined faster with the cold solution than with the warm one Sourness was more intense with the warm solution and the flavor intensity lasted longer with the warm solution than with the cold one Surprisingly, there was no difference in perceived sweetness between the cold and warm sugar solutions, but it took longer for the cold solution to reach its maximum flavor intensity. The authors conclude: "For some individuals, temperature alone can elicit taste sensations. These individuals seem to be more sensitive to tastes in general. What our work shows is that, in addition to these sensitive individuals, the temperature of a specific taste can affect how intense it tastes."