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.[75][76] 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.[77] Germany created a similar scheme in 2002, although it has not yet achieved the authority of the other countries' classification systems.[78][79] Spain, Greece and Italy have classifications based on a dual system of region of origin and product quality.[80]

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.[88] 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.[89] 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.[90]
Food poisoning has been recognized as a disease since as early as Hippocrates.[135] The sale of rancid, contaminated, or adulterated food was commonplace until the introduction of hygiene, refrigeration, and vermin controls in the 19th century. Discovery of techniques for killing bacteria using heat, and other microbiological studies by scientists such as Louis Pasteur, contributed to the modern sanitation standards that are ubiquitous in developed nations today. This was further underpinned by the work of Justus von Liebig, which led to the development of modern food storage and food preservation methods.[136] In more recent years, a greater understanding of the causes of food-borne illnesses has led to the development of more systematic approaches such as the Hazard Analysis and Critical Control Points (HACCP), which can identify and eliminate many risks.[137]
Most food has its origin in plants. Some food is obtained directly from plants; but even animals that are used as food sources are raised by feeding them food derived from plants. Cereal grain is a staple food that provides more food energy worldwide than any other type of crop.[2] Corn (maize), wheat, and rice – in all of their varieties – account for 87% of all grain production worldwide.[3][4][5] Most of the grain that is produced worldwide is fed to livestock.