Cooking requires applying heat to a food which usually, though not always, chemically changes the molecules, thus changing its flavor, texture, appearance, and nutritional properties. Cooking certain proteins, such as egg whites, meats, and fish, denatures the protein, causing it to firm. There is archaeological evidence of roasted foodstuffs at Homo erectus campsites dating from 420,000 years ago. Boiling as a means of cooking requires a container, and has been practiced at least since the 10th millennium BC with the introduction of pottery.
Wine cellars, or wine rooms, if they are above-ground, are places designed specifically for the storage and aging of wine. Fine restaurants and some private homes have wine cellars. In an active wine cellar, temperature and humidity are maintained by a climate-control system. Passive wine cellars are not climate-controlled, and so must be carefully located. Because wine is a natural, perishable food product, all types—including red, white, sparkling, and fortified—can spoil when exposed to heat, light, vibration or fluctuations in temperature and humidity. When properly stored, wines can maintain their quality and in some cases improve in aroma, flavor, and complexity as they age. Some wine experts contend that the optimal temperature for aging wine is 13 °C (55 °F), others 15 °C (59 °F).
A 2003 report by archaeologists indicates a possibility that grapes were mixed with rice to produce mixed fermented drinks in China in the early years of the seventh millennium BC. Pottery jars from the Neolithic site of Jiahu, Henan, contained traces of tartaric acid and other organic compounds commonly found in wine. However, other fruits indigenous to the region, such as hawthorn, cannot be ruled out. If these drinks, which seem to be the precursors of rice wine, included grapes rather than other fruits, they would have been any of the several dozen indigenous wild species in China, rather than Vitis vinifera, which was introduced there 6000 years later.
Human diet was estimated to cause perhaps around 35% of cancers in a human epidemiological analysis by Richard Doll and Richard Peto in 1981. These cancer may be caused by carcinogens that are present in food naturally or as contaminants. Food contaminated with fungal growth may contain mycotoxins such as aflatoxins which may be found in contaminated corn and peanuts. Other carcinogens identified in food include heterocyclic amines generated in meat when cooked at high temperature, polyaromatic hydrocarbons in charred meat and smoked fish, and nitrosamines generated from nitrites used as food preservatives in cured meat such as bacon.
The process of making a diet version of a food usually requires finding an acceptable low-food-energy substitute for some high-food-energy ingredient. This can be as simple as replacing some or all of the food's sugar with a sugar substitute as is common with diet soft drinks such as Coca-Cola (for example Diet Coke). In some snacks, the food may be baked instead of fried thus reducing the food energy. In other cases, low-fat ingredients may be used as replacements.
Literary references to wine are abundant in Homer (8th century BC, but possibly relating earlier compositions), Alkman (7th century BC), and others. In ancient Egypt, six of 36 wine amphoras were found in the tomb of King Tutankhamun bearing the name "Kha'y", a royal chief vintner. Five of these amphoras were designated as originating from the king's personal estate, with the sixth from the estate of the royal house of Aten. Traces of wine have also been found in central Asian Xinjiang in modern-day China, dating from the second and first millennia BC.
Some blended wine names are marketing terms whose use is governed by trademark law rather than by specific wine laws. For example, Meritage (sounds like "heritage") is generally a Bordeaux-style blend of Cabernet Sauvignon and Merlot, but may also include Cabernet Franc, Petit Verdot, and Malbec. Commercial use of the term Meritage is allowed only via licensing agreements with the Meritage Association.
Packaged foods are manufactured outside the home for purchase. This can be as simple as a butcher preparing meat, or as complex as a modern international food industry. Early food processing techniques were limited by available food preservation, packaging, and transportation. This mainly involved salting, curing, curdling, drying, pickling, fermenting, and smoking. Food manufacturing arose during the industrial revolution in the 19th century. This development took advantage of new mass markets and emerging technology, such as milling, preservation, packaging and labeling, and transportation. It brought the advantages of pre-prepared time-saving food to the bulk of ordinary people who did not employ domestic servants.
According to Canadian Food and Drug Regulations, wine in Canada is an alcoholic drink that is produced by the complete or partial alcoholic fermentation of fresh grapes, grape must, products derived solely from fresh grapes, or any combination of them. There are many materials added during the course of the manufacture, such as yeast, concentrated grape juice, dextrose, fructose, glucose or glucose solids, invert sugar, sugar, or aqueous solutions. Calcium sulphate in such quantity that the content of soluble sulphates in the finished wine shall not exceed 0.2 per cent weight by volume calculated as potassium sulphate. Calcium carbonate in such quantity that the content of tartaric acid in the finished wine shall not be less than 0.15 per cent weight by volume. Also, sulphurous acid, including salts thereof, in such quantity that its content in the finished wine shall not exceed 70 parts per million in the free state, or 350 parts per million in the combined state, calculated as sulphur dioxide. Caramel, amylase and pectinase at a maximum level of use consistent with good manufacturing practice. Brandy, fruit spirit or alcohol derived from the alcoholic fermentation of a food source distilled to not less than 94 per cent alcohol by volume.[clarification needed] Prior to final filtration may be treated with a strongly acid cation exchange resin in the sodium ion form, or a weakly basic anion exchange resin in the hydroxyl ion form.
Vitamins and minerals are required for normal metabolism but which the body cannot manufacture itself and which must therefore come from external sources. Vitamins come from several sources including fresh fruit and vegetables (Vitamin C), carrots, liver (Vitamin A), cereal bran, bread, liver (B vitamins), fish liver oil (Vitamin D) and fresh green vegetables (Vitamin K). Many minerals are also essential in small quantities including iron, calcium, magnesium, sodium chloride and sulfur; and in very small quantities copper, zinc and selenium. The micronutrients, minerals, and vitamins in fruit and vegetables may be destroyed or eluted by cooking. Vitamin C is especially prone to oxidation during cooking and may be completely destroyed by protracted cooking.[not in citation given] The bioavailability of some vitamins such as thiamin, vitamin B6, niacin, folate, and carotenoids are increased with cooking by being freed from the food microstructure. Blanching or steaming vegetables is a way of minimizing vitamin and mineral loss in cooking.
In whole grain foods, the higher fiber content effectively displaces some of the starch component of the flour. Since certain fibers have no food energy, this results in a modest energy reduction. Another technique relies on the intentional addition of other reduced-food-energy ingredients, such as resistant starch or dietary fiber, to replace part of the flour and achieve a more significant energy reduction.