Factors Affecting Taste
Not everyone perceives the taste of a piece of apple pie the same way. There is considerable genetic variation among individuals in sensitivity to basic tastes. Tasting abilities may also vary within the individual, depending on a number of outside influences. The temperature of a food or beverage affects its taste. As food or beverage temperatures go below 68°F (20°C) or above 86°F (30°C), it becomes harder to distinguish their tastes accurately. For example, very hot coffee tastes less bitter, while slightly melted ice cream tastes sweeter. Other factors influencing taste include the color of the food, the time of day it is eaten, and the age, gender, and degree of hunger of the taster.
Variety in available food choices also affects taste. This can be seen when the “taste” and appetite for a food eaten day after day starts to diminish. Even favorite foods consumed every day for awhile can lose their appeal. Some weight-reducing fad diets are based on this principle, banking on the idea that people will get tired of eating just one type of food and therefore will come to eat less. Grapefruit for breakfast, for lunch, and for dinner quickly becomes boring and unappetizing.
In examining the factors affecting taste, it is important to distinguish between taste and flavor. Taste relies on the taste buds’ connection to the brain via nerve cells, which signal the sensations of sour, salt, sweet, and bitter. Flavor is a broader concept with aroma providing about 75 percent of the impression of flavor. To get some idea of how the ability to smell affects flavor perception, think of having a cold with a badly stuffed up nose.
Everything tastes different. The nasal congestion interferes with the function of the olfactory sense, impairing the ability to detect the aromas that contribute to the perception of flavor. Some apply this principle to their advantage by pinching their nostrils shut to lessen the bad flavor of a disagreeable medicine they must swallow.
The amount of fat in a food or beverage determines how intense the flavor is over time. The maximum intensity of flavor compounds dissolved in fat is perceived later and lasts longer than that of water-soluble flavor compounds, which furnish their intensity peak in the beginning, but disappear much more quickly. This explains why a reduced-fat product is much less likely to duplicate the flavor of the original food: the original fat’s flavor compounds are missing, which also causes an imbalance of the other flavors present. Reduced-fat cookies, for example, taste sweeter unless they are modified to compensate. It is even more difficult to replace fats that, in addition to contributing to traditional flavor releases and mouthfeel, also have their own distinctive flavor, as is the case for butter, olive oil, and bacon fat.
Flavors, regardless of the medium in which they are dissolved, do not stay at the same intensity day after day, but diminish over time. Sensory chemists and flavor technologists know that one way to keep the food products sold by manufacturers from losing their appeal is to prevent the volatile compounds responsible for flavor from deteriorating, escaping, or reacting with other substances. They look at methods in processing, storage, and cooking, all of which affect the volatile flavor compounds, to devise strategies against these occurrences. One major function of protective packaging is to retain a food’s flavor. Packaging guards flavor in several ways. It protects against vaporization of the volatile compounds and against physical damage that could expose food to the air and result in off-odors. It keeps unpleasant odors from the outside from attaching to the food. It also prevents “flavor scalping,” or the migration of flavor compounds from the packaging (sealers, solvents, etc.) to the food or vice versa.