261024机考雅思阅读 Food flavor-托您的福

Look at the labels on the food in your kitchen. You’ll find ‘flavor’ in almost every list of ingredients. These additives give processed food most of its taste. Research has demonstrated that people usually buy a food item the first time because of its packaging or appearance, but flavor determines whether they buy it again. The canning, freezing, and dehydrating techniques used in processing food destroy most of its flavor and so a vast industry has arisen to make processed food attractive to eat.

Scientists believe that human beings acquired the sense of taste to avoid being poisoned. Edible plants generally taste sweet, harmful ones bitter. The taste buds on our tongues can detect the presence of half a dozen basic tastes, but they offer a limited means of detection compared with the human sense of smell, which can perceive thousands of different aromas. Indeed, what we commonly perceive as ‘flavor’ is primarily the smell of gases produced by the chemicals we’ve just released by chewing our food.

Flavor in previous centuries

The human desire for flavor has been a largely unacknowledged force in history, but for millennia royal empires have been built and unexplored lands ‘discovered’ in the search for flavor enhancers such as spices. In 1492, Christopher Columbus, usually credited with the European discovery of the Americas, set sail with the primary goal of finding a more direct way to the East Indies, the source of popular natural seasonings. Today, the rise and fall of corporate empires of soft-drink makers, snack-food companies, and fast-food chains – is often determined by the flavor of their products.

The flavor industry emerged in the mid-19th century as processed food began to be manufactured on a large scale. The food processing industry soon recognized the need to add more taste to their products and turned to the great perfume houses of England, France and the Netherlands. These companies used their long experience of working with essential oils and volatile aromas to develop and supply the industry with flavor additives. In the early 20th century, Germany took the technological lead in flavor production, owing to its powerful chemical industry. In the late 1940s, much of the fashion industry shifted from Europe to the USA, and the fragrance and flavor industries also moved in the same direction soon afterwards. The invention of gas chromatographs and mass spectrometers scientific instruments capable of detecting low levels of the volatile gases used to create flavors – vastly increased the number of flavors that could be created artificially.

Humans versus machines

Today, improved models of these sophisticated instruments can provide detailed analyses of food’s flavor components, detecting chemical aromas present in amounts as low as one part per billion. The nose, however, is even more sensitive. A nose can detect aromas present in amounts of a small number of parts per trillion. The smell of strawberries comes from about 350 chemicals that are present in minute amounts. Complex aromas, such as those of coffee and roasted meat, are composed of volatile gases from nearly a thousand chemicals.

Color and taste

Many flavor companies also manufacture color additives used to make food look appealing. Food coloring is often made from the same basic color compounds as those used for making other, surprisingly different, products. A case in point is titanium dioxide, which gives many processed foods, such as candies, a bright white color, and is also a common ingredient in women’s cosmetics, as well as in many oil paints.

Studies have found that the color of a food greatly affects how its taste is perceived. Brightly-colored foods frequently seem to taste better than paler-colored foods, even when the flavor compounds are identical. Humans have probably always relied on visual cues to help determine what is edible. The color of fruit suggests its ripeness, the color of meat its freshness. It is not uncommon for flavor researchers to employ colored lights to modify visual cues. During one such experiment, people were served an oddly-colored meal of steak and fries that appeared normal under these lights. Everyone thought the meal tasted fine until the lighting was changed and it became apparent that the steak was blue and the fries were green, at which point some people became ill.

Food ingredients

Consumers seem to prefer foods containing flavors labeled as ‘natural’, but the distinction between ‘artificial’ and ‘natural’ flavors is inconsistent and somewhat absurd, depending on whether the flavor has been derived from its contents. Amyl acetate, for example, provides the dominant ingredient of the banana flavor. When it is distilled from bananas with a solvent, it is classified as ‘natural’. When produced by mixing vinegar with amyl alcohol and adding sulphuric acid as a catalyst, amyl acetate is considered ‘artificial’. Either way, it smells and tastes exactly the same.

The North American flavor industry

The North American flavor industry now has annual revenues of billions of dollars. Approximately 10,000 new processed food products are introduced every year in the USA and almost all of them require flavor additives. In fact, nine out of ten of these new product introductions end in failure. But the potential profits are huge for those companies producing the products which do succeed. As the flavor additives are often less expensive than the food’s packaging, food companies are only too happy to try out a variety of new flavors. Even in soft drinks, which contain a larger percentage of flavor additives than most other products, the flavor adds a relatively minor amount to the expense of production.