Food is any substance consumed to provide nutritional support for the body. 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 in an effort to produce energy, maintain life, or stimulate growth.
Historically, people secured food through two methods: hunting and gathering, and agriculture. Today, most of the food energy consumed by the world population is supplied by the food industry.
A garde manger (French for "keeper of the food") is a cool, well-ventilated area where cold dishes (such as salads, hors d'œuvres, appetizers, canapés, pâtés and terrines) are prepared and other foods are stored under refrigeration. The person in charge of this area is known as the chef garde manger. Larger hotels and restaurants may have garde manger staff perform additional duties, such as creating decorative elements of buffet presentation like ice carving and edible centerpieces made from materials such as cheese, Thai fruit and vegetable carvings, butter, salt dough or tallow.
The term "garde manger" originated in pre-Revolutionary France. At that time, maintaining a large supply of food and beverage was an outward symbol of power, wealth and status. It is because of this duty of supervising the preserving of food and managing its utilization that many interpret the term "garde manger".
Food preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), and other micro-organisms (although some methods work by introducing benign bacteria or fungi to the food), as well as retarding the oxidation of fats that cause rancidity. Food preservation can also include processes that inhibit visual deterioration, such as the enzymatic browning reaction in apples after they are cut, which can occur during food preparation.
Many processes designed to preserve food will involve a number of food preservation methods. Preserving fruit by turning it into jam, for example, involves boiling (to reduce the fruit’s moisture content and to kill bacteria, yeasts, etc.), sugaring (to prevent their re-growth) and sealing within an airtight jar (to prevent recontamination). There are many traditional methods of preserving food that limit the energy inputs and reduce carbon footprint.