Food sources
Almost all foods are of plant or animal origin, although there are some exceptions. Foods not coming from animal or plant sources include various edible fungi, including mushrooms. Fungi and ambient bacteria are used in the preparation of fermented and pickled foods such as leavened bread, wine, beer, cheese, pickles, and yogurt. Many cultures eat seaweed, which is a protist, or blue-green algae (cyanobacteria)such as Spirulina.[1] Additionally, salt is often eaten as a flavoring or preservative, and baking soda is used in food preparation. Both of these are inorganic substances, as is water, an important part of human diet.
Plants
Many plants or plant parts are eaten as food. There are around 2,000 plant species which are cultivated for food, and many have several distinct cultivars.[2] Plant-based foods can be classified as with the nutrients necessary for the plant's initial growth. Because of this, seeds are often packed with energy, and are good sources of food for animals, including humans. In fact, the majority of all foods consumed by human beings are seeds. These include cereals (such as maize, wheat, and rice), legumes (such as beans, peas, andlentils), and nuts. Oilseeds are often pressed to produce rich oils, including sunflower, rape (including canola oil), and sesame.[3] One of the earliest food recipes made from ground chickpeas is called hummus, which can be traced back to the Ancient Egypt times.
Fruits are the ripened extensions of plants, including the seeds within. Fruits are made attractive to animals so that animals will eat the fruits and excrete the seeds over long distances. Fruits, therefore, make up a significant part of the diets of most cultures. Some fruits, such as pumpkin and eggplant, are eaten as vegetables.[4] (For more information, see list of fruits.)
Vegetables are a second type of plant matter eaten as food. These include root vegetables (such as potatoesand carrots), leaf vegetables (such as spinach and lettuce), stem vegetables (such as bamboo shoots andasparagus), and inflorescence vegetables (such as globe artichokes and broccoli). Many herbs and spices are highly-flavorful vegetables.[5]
Animals
Animals can be used as food either directly, or indirectly by the products they produce. Meat is an example of a direct product taken from an animal, which comes from either muscle systems or fromorgans. Food products produced by animals include milk produced by mammals, which in many cultures is drunk or processed into dairy products such as cheese or butter. In addition birds and other animals lay eggs, which are often eaten, and bees produce honey, a popular sweetener in many cultures. Some cultures consume blood, some in the form of blood sausage, as a thickener for sauces, a cured salted form for times of food scarcity, and others use blood in stews such as civet.[6]
Production
Food is traditionally obtained through farming, ranching, and fishing, with hunting, foragingand other methods of subsistence locally important. More recently, there has been a growing trend towards more sustainable agricultural practices. This approach, which is partly fueled by consumer demand, encourages biodiversity, local self-reliance and organic farmingmethods.[7] Major influences on food production are international organizations, (e.g. theWorld Trade Organization and Common Agricultural Policy), national government policy (orlaw), and war.[8]
Preparation
While some food can be eaten raw, many foods undergo some form of preparation for reasons of safety, palatability, or flavor. At the simplest level this may involve washing,cutting, trimming or adding other foods or ingredients, such as spices. It may also involve mixing, heating or cooling, pressure cooking, fermentation, or combination with other food. In a home, most food preparation takes place in a kitchen. Some preparation is done to enhance the taste or aesthetic appeal; other preparation may help to preserve the food; and others may be involved in cultural identity. Ameal is made up of food which is prepared to be eaten at a specific time and place.[9]
Animal slaughter and butchering
The preparation of animal-based food will usually involve slaughter, evisceration, hanging, portioning and rendering. In developed countries, this is usually done outside the home in slaughterhouses which are used to process animals en mass for meat production. Many countries regulate their slaughterhouses by law. For example theUnited States has established the Humane Slaughter Act of 1958, which requires that an animal be stunned before killing. This act, like those in many countries, exempts slaughter in accordance to religious law, such as kosher shechita and dhabiĥa halal. Strict interpretations of kashrut require the animal to be fully aware when its carotid artery is cut.[10]
On the local level a butcher may commonly break down larger animal meat into smaller manageable cuts and pre-wrapped for commercial sale or wrapped to order in butcher paper. In addition fish and seafood may be fabricated into smaller cuts by a fish mongerat the local level. However fish butchery may be done on board a fishing vessel and quick-frozen for preservation of quality.[11]
Cooking
The term "cooking" encompasses a vast range of methods, tools and combinations of ingredients to improve the flavor or digestibility of food. Cooking technique, known as culinary art, generally requires the selection, measurement and combining of ingredients in an ordered procedure in an effort to achieve the desired result. Constraints on success include the variability of ingredients, ambient conditions, tools, and the skill of the individual cooking.[12] The diversity of cooking worldwide is a reflection of the myriad nutritional, aesthetic, agricultural, economic, cultural and religious considerations that impact upon it.[13]
Cooking requires applying heat to a food which usually, though not always, chemically transforms it, thus changing its flavor, texture, appearance, and nutritional properties.[14] Cooking proper, as opposed to roasting, requires the boiling of water in a container, and was practiced at least since the 10th millennium BC with the introduction of pottery.[15] There is archaeological evidence of roasted foodstuffs at Homo erectus campsites dating from 420,000 years ago.[16]
Cooking equipment and methods
There are many types of cooking equipment used for cooking. Ovens are one type of cooking equipment which can be used for baking or roasting and offer a dry-heat cooking method. Different cuisines will use different types of ovens, for example Indian culture uses a Tandoor oven is a cylindrical clay oven which operates at a single high temperature,[17] while western kitchens will use variable temperature convection ovens, conventional ovens, toaster ovens in addition to non-radiant heat ovens like the microwave oven. Ovens may be wood-fired, coal-fired, gas, electric, or oil-fired.[18]
Various types of cook-tops are used as well. They carry the same variations of fuel types as the ovens mentioned above. cook-tops are used to heat vessels placed on top of the heat source, such as a sauté pan, sauce pot, frying pan, pressure cooker, etc. These pieces of equipment can use either a moist or dry cooking method and include methods such as steaming, simmering, boiling, and poaching for moist methods; while the dry methods include sautéing, pan frying, or deep-frying.[19]
In addition, many cultures use grills for cooking. A grilloperates with a radiant heat source from below, usually covered with a metal grid and sometimes a cover. An open bit barbecue in the American south is one example along with the American style outdoor grill fueled by wood, liquidpropane or charcoal along with soaked wood chips for smoking.[20] A Mexican style of barbecue is called barbacoa, which involves the cooking of meats and whole sheep over open fire. In Argentina, asado is prepared on a grill held over an open pit or fire made upon the ground, on which a whole animal is grilled or in other cases smaller cuts of the animal.[21]
Raw food
Certain cultures highlight animal and vegetable foods in their raw state. Sushi in Japan is one such cuisine that features raw sliced fish, either in sashimi, nigiri, or maki styles.[22] Steak tartare and salmon tartare are dishes made from diced or ground raw beef or salmon respectively, mixed with various ingredients and served with baguette, brioche orfrites.[23] In Italy, carpaccio is a dish of very thin sliced raw beef, drizzled with a vinaigrette made with olive oil.[24] A popular health food movement known as raw foodism promotes a mostly vegan diet of raw fruits, vegetables and grains prepared in various ways, including juicing, food dehydration, not passing the 118 degree mark, and sprouting.[25]
Restaurants
Many cultures produce food for sale in restaurants for paying customers. These restaurants often have trained chefs who prepare the food, while trained waitstaff serve the customers. The term restaurant is credited to the French from the 19th century, as it relates to the restorative nature of the bouillons that were once served in them. However, the concept pre-dates the naming of these establishments, as evidence suggests commercial food preparation may have existed during the age of the city of Pompeii, as well as an urban sales of prepared foods in China during theSong Dynasty. The coffee shops or cafes of 17th century Europe may also be considered an early version of the restaurant.[26] In 2005 the United States spent $496 billion annually for out-of-home dining. Expenditures by type of out-of-home dining was as follows, 40% in full-service restaurants, 37.2% in limited service restaurants (fast food), 6.6% in schools or colleges, 5.4% in bars and vending machines, 4.7% in hotels and motels, 4.0% in recreational places, and 2.2% in other which includes military bases.[27]
Food manufacture
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, fermentation and smoking.[28] During the industrialization era in the 19th century, food manufacturing arose.[29] This development took advantage of new mass markets and emerging new technology, such as milling, preservation, packaging andlabeling and transportation. It brought the advantages of pre-prepared time saving food to the bulk of ordinary people who did not employ domestic servants.[30]
At the start of the 21st century, a two-tier structure has arisen, with a few international food processing giants controlling a wide range of well-known food brands. There also exists a wide array of small local or national food processing companies.[31] Advancedtechnologies have also come to change food manufacture. Computer-based control systems, sophisticated processing and packagingmethods, and logistics and distribution advances, can enhance product quality, improve food safety, and reduce costs.[30]
