On food and cooking the science and lore of the kitchen ( PDFDrive ) 1487

scratched, and food sticks to the scratches Beginning in the 1980s, flexible nonstick sheets and containers made of silicone have been used by bakers to line metal baking sheets or replace molded metal pans Silicone is also a long-chain molecule, with a backbone of alternating silicon and oxygen atoms, and small fatlike carbon chains projecting from it The backbone gives the material its flexibility, and the hydrophobic projections make the surface behave like a permanently welloiled pan surface Food-grade silicones decompose at temperatures above about 480ºF/240ºC, so like nonstick pans, silicone bakeware must be used with some caution Copper Copper is unique among the common metals because it can be found naturally in the metallic state For this reason it was the first metal to be used in tool making, about 10,000 years ago In the kitchen, it is prized for its unmatched conductivity, which makes fast and even heating a simple matter But copper is also relatively expensive, since its conductivity has made it the preferred material for millions of miles of electrical circuitry It is troublesome to keep polished, because it has a high affinity for oxygen and sulfur, and forms a greenish coating when exposed to air Most important, copper cookware can be harmful Its oxide coating is sometimes porous and powdery, and copper ions are easily leached into food solutions Copper ions can have useful effects: they stabilize foamed egg whites (p 102), and the green color of cooked vegetables is improved by their presence But the human body can excrete copper in only limited amounts, and excessive intake may cause gastrointestinal problems and, in more extreme cases, liver ... sometimes porous and powdery, and copper ions are easily leached into food solutions Copper ions can have useful effects: they stabilize foamed egg whites (p 102), and the green color of cooked vegetables is improved... is also relatively expensive, since its conductivity has made it the preferred material for millions of miles of electrical circuitry It is troublesome to keep polished, because it has a high affinity for oxygen and sulfur, and forms a greenish coating when...metallic state For this reason it was the first metal to be used in tool making, about 10,000 years ago In the kitchen, it is prized for its unmatched conductivity, which makes fast and even heating a simple matter