On food and cooking the science and lore of the kitchen ( PDFDrive ) 494

prestige and availability pushed grains, vegetables, and fruits to the side of the plate and the end of the meal And for decades, nutritional science affirmed their accessory status Fruits and vegetables in particular were considered to be the source of a few nutrients that we need only in small amounts, and of mechanically useful roughage In recent years, though, we’ve begun to realize just how many valuable substances plant foods have always held for us And we’re still learning Essential Nutrients in Fruits and Vegetables: Vitamins Most fruits and vegetables contribute only modestly to our intake of proteins and calories, but they’re our major source for several vitamins They provide nearly all of our vitamin C, much of our folic acid, and half of our vitamin A Each of these plays a number of roles in the metabolism of our cells For example, vitamin C refreshes the chemical state of metal components in many enzymes, and helps with the synthesis of connective-tissue collagen Vitamin A, which our bodies make from a precursor molecule in plants called beta-carotene (p 267), helps regulate the growth of several different kinds of cells, and helps our eyes detect light Folic acid, named from the Latin word for “leaf,” converts a by-product of our cells’ metabolism, homocysteine, into the amino acid methionine This prevents homocysteine levels from rising, causing damage to blood vessels, and possibly contributing to heart disease and stroke Genetic Engineering and Food The most far-reaching development in 20th-century agriculture was the introduction in the 1980s of genetic engineering, the technology that makes it possible to alter our food plants and ...cells For example, vitamin C refreshes the chemical state of metal components in many enzymes, and helps with the synthesis of connective-tissue collagen Vitamin A, which our bodies make from a precursor molecule in... plants called beta-carotene (p 267), helps regulate the growth of several different kinds of cells, and helps our eyes detect light Folic acid, named from the Latin word for “leaf,” converts a by-product of our cells’... metabolism, homocysteine, into the amino acid methionine This prevents homocysteine levels from rising, causing damage to blood vessels, and possibly contributing to heart disease and stroke Genetic Engineering and Food The