What Einstein Told His Cook Read Free Page A

down” just before the throat.
    Traditionally, it has been thought that there are only four primary tastes: sweet, sour, salty, and bitter, and that we have specialized taste buds for each. Today, it is generally agreed that there is at least one other primary taste, known by its Japanese name, umami . It is associated with MSG (monosodium glutamate) and other compounds of glutamic acid, one of the common amino acids that are the building blocks of proteins. Umami is a savory kind of taste associated with protein-rich foods such as meat and cheese. Moreover, it is no longer believed that each taste bud responds exclusively to a single kind of stimulus, but that it may also respond in lesser degrees to others.
    Thus, the standard “map of the tongue” in textbooks, illustrating sweet buds at the tip, salty buds on either side of the tip, sour buds along the sides, and bitter buds at the back, is an oversimplification; it shows only the areas where the tongue is most sensitive to the primary tastes. What we actually taste is the overall pattern of stimuli from all the taste receptors, the cells within the taste buds that actually detect the various tastes. The recent success in sequencing the human genome has enabled researchers to identify the probable genes that produce the receptors for bitterness and sweetness, but not yet for the others.
    When the combined taste, smell, and textural stimuli reach the brain, they remain to be interpreted. Whether the overall sensation will be pleasant, repulsive, or somewhere in between will depend on individual physiological differences, on previous experience (“just like my mother used to make”), and on cultural habituation (haggis, anyone?).
    One taste sensation is undeniably the favorite of our species and of many others in the animal kingdom from hummingbirds to horses: sweetness. To paraphrase a famously ungrammatical advertising slogan, nobody doesn’t like sweetness. Nature undoubtedly set us up for that by making good foods such as ripe fruits taste sweet and poisonous ones, such as those that contain alkaloids, taste bitter. (The alkaloid family of plant chemicals includes such bad actors as morphine, strychnine, and nicotine, not to mention caffeine.)
    In our menus, there is only one taste that has an entire course devoted to it: the sweetness of dessert. Appetizers may be savory, main courses may have any complex combination of flavors, but dessert is invariably and sometimes overwhelmingly sweet. We love sweetness so much that we use its concept in terms of endearment (sweetheart, honey) and to describe almost anything or anyone that is particularly pleasant, such as sweet music and a sweet disposition.
    When we think of sweetness, we think immediately of sugar. But the word sugar does not denote a unique substance; it is a generic term for a whole family of natural chemical compounds that, along with starches, belong to the family of carbohydrates. So before we indulge our sweet tooth—before beginning our scientific repast with dessert—we must see where sugars fit into the scheme of carbohydrates.
    FILL ’ER UP
     
    I know that starch and sugar are both carbohydrates, but they’re such different substances. Why are they lumped together in the same category when we talk about nutrition?
     
    I n a word: fuel. When a runner loads up on “carbs” before a race, it’s like a car filling up at the gas station.
    Carbohydrates are a class of natural chemicals that play vital roles in all living things. Both plants and animals manufacture, store, and consume starches and sugars for energy. Cellulose, a complex carbohydrate, makes up the cell walls and structural frameworks of plants—their bones, if you will.
    These compounds were named carbohydrates in the early eighteenth century when it was noticed that many of their chemical formulas could be written as if they were made up of carbon atoms (C) plus a number of water molecules (H 2 O). Thus, the name carbohydrate