For some foods alternative ingredients can be used. Common oils and fats become rancid relatively quickly if not refrigerated; replacing them with hydrogenated oils delays the onset of rancidity, increasing shelf life. This is a common approach in industrial food production, but recent concerns about health hazards associated with trans fats have led to their strict control in several jurisdictions. Even where trans fats are not prohibited, in many places there are new labeling laws (or rules), which require information to be printed on packages, or to be published elsewhere, about the amount of trans fat contained in certain products.
Outstanding vintages from the best vineyards may sell for thousands of dollars per bottle, though the broader term "fine wine" covers those typically retailing in excess of US$30–50. "Investment wines" are considered by some to be Veblen goods: those for which demand increases rather than decreases as their prices rise. Particular selections have higher value, such as "Verticals", in which a range of vintages of a specific grape and vineyard, are offered. The most notable was a Château d'Yquem 135 year vertical containing every vintage from 1860 to 2003 sold for $1.5 million. The most common wines purchased for investment include those from Bordeaux and Burgundy; cult wines from Europe and elsewhere; and vintage port. Characteristics of highly collectible wines include:
France has various appellation systems based on the concept of terroir, with classifications ranging from Vin de Table ("table wine") at the bottom, through Vin de Pays and Appellation d'Origine Vin Délimité de Qualité Supérieure (AOVDQS), up to Appellation d'Origine Contrôlée (AOC) or similar, depending on the region. Portugal has developed a system resembling that of France and, in fact, pioneered this concept in 1756 with a royal charter creating the Demarcated Douro Region and regulating the production and trade of wine. Germany created a similar scheme in 2002, although it has not yet achieved the authority of the other countries' classification systems. Spain, Greece and Italy have classifications based on a dual system of region of origin and product quality.
Investment in fine wine has attracted those who take advantage of their victims' relative ignorance of this wine market sector. Such wine fraudsters often profit by charging excessively high prices for off-vintage or lower-status wines from well-known wine regions, while claiming that they are offering a sound investment unaffected by economic cycles. As with any investment, thorough research is essential to making an informed decision.
Sourness is caused by the taste of acids, such as vinegar in alcoholic beverages. Sour foods include citrus, specifically lemons, limes, and to a lesser degree oranges. Sour is evolutionarily significant as it is a sign for a food that may have gone rancid due to bacteria. Many foods, however, are slightly acidic, and help stimulate the taste buds and enhance flavor.
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.
Food is any substance consumed to provide nutritional support for an organism. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingested by an organism and assimilated by the organism's cells to provide energy, maintain life, or stimulate growth.