A cook prepares food for consumption. Cooking techniques and ingredients vary widely across the world, reflecting unique environmental conditions, economic contexts and cultural traditions. The way in which food is prepared also depends on an individual cook's skills and training. In many countries, cooks must be properly trained and/or certified if they are providing food to the public. There are several jobs related to the preparation and serving of food. In Belarus, some of the most important are:
  • chief cook, who is responsible for the food products purchased and for their quality and preservation; for developing menus; and for maintaining kitchen hygiene;
  • confectioner, who specialises in making chocolate, cakes and sweets; and
  • food technician, who studies cooking processes and food safety issues and develops new recipes.

  • Cooking is a part of daily life. The preparation of food using heat or fire is an activity unique to humans, and scientists believe the advent of cooking played an important role in human evolution. Most anthropologists think that humans first used fires to cook their food as long as 250,000 years ago. The expansion of agriculture, commerce, trade and transportation between civilisations in different regions made many new ingredients available. New inventions and technologies have also expanded the range of cooking techniques.
  • Traditional cooking methods, many of them used since antiquity, include baking, roasting, stewing, frying, grilling, barbecuing, smoking, boiling, steaming and braising. A more recent innovation is microwaving. The different methods use differing levels of heat and moisture and involve shorter or longer cooking times, and the selected method greatly depends on the type of food being cooked. Some food preparation involves the use of chemical techniques such as fermenting, marinating, salting, pickling and curing. Today, many appliances are available to help with cutting, chopping, mixing, milling, vacuum filling and kneading.
Food production is responsible for a significant share of national energy consumption (more than 10 percent in developed countries), and cooking accounts for almost one-fifth of household energy use. Refrigeration and dishwashing further increase daily household energy consumption. Consumer education has the greatest potential for reducing energy demand in the kitchen. More efficient appliances and the promotion of alternatives to traditional cooking methods can also make a positive difference.

Cooking equipment

  • Most stoves run on gas, or on electricity produced from coal, gas, nuclear power, hydropower or other renewables. The conversion efficiency rate from coal to electricity in conventional power plants is roughly 30 percent, or 40 percent in plants with special equipment. Natural gas plants can reach efficiency rates of up to 60 percent. By contrast, the typical gas stove in America is only 40 percent efficient, whereas its electric counterpart achieves an efficiency rate of 80 percent. Based on current findings, electric stoves are 20 percent more efficient than others.
  • Apart from the type of fuel used, the model of oven or stove and the size and style of pan can make a big difference to the amount of energy consumed. On the top of a stove, a pan should fully cover the burner (with no flame or heating element visible around the edges). The most efficient pans are made of a material that is a good conductor of heat (such as copper or iron). Glass and ceramic kitchenware, which performs less efficiently on the stove top, are the best choices for ovens, where food is heated by radiation rather than conduction. In convection ovens, heat is circulated by a fan, which reduces pre-heating times, eliminates hotspots and lowers cooking temperatures, making them a more energy-efficient choice than non-convection ovens. Good-quality appliances are also well insulated.
  • The majority of homes now have microwaves and various appliances such as rice cookers and electric kettles. Many studies agree that appliances such as these “consistently utilise less energy” than traditional alternatives. The merits of microwave ovens are less clear, but they do seem to be an efficient choice for small portions and foods with short cooking times. Foods that need to be simmered for longer times should probably not be cooked in a microwave. Dry beans, for example, can be cooked more efficiently on the stove.  A single hamburger is better heated in the microwave, while four hamburgers can be cooked on the stove using less energy.

Commercial kitchens
  • Efficient methods to control the large number of air pollutants that pose risks to human health and the environment are an essential part of society's efforts to protect the environment. These pollutants include harmful emissions from commercial kitchens, such as smoke, exhausted gases, irritant smells and tiny solid particles.
  • Fatty foods cooked on high heat, especially over an open flame, create the most emissions from commercial kitchens. The use of certain oils may also increase emissions.

Household kitchens
  • Primarily in the developing world, noxious and hazardous emissions from cooking stoves in poorly ventilated houses are a major cause of health problems, including acute and chronic respiratory diseases, cancer of the aerodigestive tract and lungs, burns, eye disease, low birth weight and increased infant mortality. Several hundred million people in developing countries are probably exposed to excessive indoor air pollution as a result of fuel combustion in cooking stoves in poorly ventilated houses. Demand for traditional fuel also puts significant pressure on local forests and woodlands, contributing to deforestation, soil erosion and desertification. In the poorest regions, inefficient fuels such as animal manure, grass, crop residues, roots and shrubs are also used.
  • Using predominantly local products is one way to reduce energy consumption for transportation, cooling and storage. It also has the benefit of promoting business for local food producers.

Cooking style
  • A conscientious cook can halve the energy consumed by someone using the same equipment more carelessly. Simply putting a lid on a saucepan during cooking can result in an eight-fold decrease in energy consumption. Another good practice is to cook food in saucepans that are filled to capacity. The efficiency of a pan is reduced by 80 percent if it is only 20 percent full. Cooking food in large batches takes advantage of the fact that boiling efficiency increases with pan size and liquid volume.
  • Opting for organic ingredients is an effective way to minimise the impact of agrochemicals on the environment and to reduce the application and further development of foods based on genetically modified organisms.
Most ingredients are derived from living organisms. Vegetables, fruits, grains and nuts, as well as herbs and spices, come from plants, while meat, eggs, and dairy products come from animals. Mushrooms and the yeast used in baking are types of fungi. Cooks also use water, minerals such as salt, and wine or spirits.

Naturally occurring ingredients contain various amounts of proteins, carbohydrates, fats, water and minerals. Cooking involves manipulating the chemical properties of these substances.

Carbohydrates — These include sucrose (common table sugar or cane sugar), a disaccharide made up of the simple sugars glucose and fructose; as well as starches such as cereal flour, rice, arrowroot and potatoes. Simple carbohydrates are chemical structures comprising one or two sugars. Complex carbohydrates, such as whole grains and vegetables, contain three or more sugars and are generally rich in fibre, vitamins and minerals.

Fats — Vegetable oils, animal products such as butter and lard, as well as grain oils such as corn and linseed oils, are all types of fat. Fats can reach temperatures higher than the boiling point of water and are often used to conduct heat to other ingredients, such as in frying or sauteing.

Protein — Edible animal products, such as meat, offal, milk and eggs, contain substantial amounts of protein. Almost all vegetable matter (in particular legumes and seeds) also includes protein, although generally in smaller amounts. Mushrooms have a high protein content. Any of these may be sources of essential amino acids. When proteins are heated they become denatured and change texture. In most cases, the material becomes softer or more friable (e.g. meat). In some cases, proteins form more rigid structures when heated (e.g. the coagulation of albumen in egg whites). The beating of egg whites to form a relatively rigid but flexible structure is an important component in baking cakes and is the basis of meringue making.

Vitamins and minerals — Vitamins are organic compounds that are required for normal metabolism, although the body cannot manufacture them itself and must obtain them from external sources. Good sources of vitamins are fresh fruit and vegetables (vitamin C); carrots and liver (vitamin A); cereal bran, bread and liver (B-group vitamins); fish-liver oil (vitamin D); and fresh green vegetables (vitamin K). Small quantities of minerals such as iron, calcium, magnesium and sulphur are also essential; and copper, zinc and selenium are needed in very small quantities. The micronutrients, minerals and vitamins contained in fruits and vegetables may be destroyed by cooking. Vitamin C is especially prone to oxidation during cooking and may be completely destroyed by protracted cooking. The availability of some vitamins such as thiamin (vitamin B1), vitamin B6, niacin (vitamin B3), folic acid (vitamin B9), and carotenoids (vitamin A) increases with cooking.

Water — Stock, wine, water or other liquids containing water are added during cooking, and water is also released from some foods as they cook. Liquids are such an important ingredient that the name of the cooking method often refers to how the liquid is used (e.g. to steam, simmer, boil, braise or blanch). When liquid is heated in an open pan, the rate of evaporation rapidly increases, concentrating the remaining ingredients and intensifying flavours. This is an essential part of stewing and sauce making.

Food poisoning and other illnesses may be caused by bacteria, viruses and protozoa in uncooked or inappropriately prepared food. Raw leaf vegetables, undercooked meat and non-boiled water may contain parasites. Cooking can kill such organisms, or make them harmless. The sterilising effect of cooking depends on temperature, cooking time and the technique used. However, some bacteria can form spores that survive cooking, which then germinate and grow after the food has cooled. It is therefore recommended that cooked food should not be reheated more than once in order to prevent bacteria from proliferating to dangerous levels.

Cooking prevents many food-borne illnesses and also increases the digestibility of some foods. Foods such as grains are inedible when raw, and some foods, like kidney beans, are poisonous if not properly cooked.

Food safety must also be taken into consideration during the preparation, handling and storage of ingredients. Cold foods should be stored at 4°C or less, and hot foods should be kept hot at 60°C or above to avoid the "danger zone" in which bacteria are most likely to proliferate. Good practices include washing hands and wiping down surfaces, and avoiding cross-contamination.  Plastic chopping boards may be less likely to harbour bacteria than wooden ones. It is recommended to washing and sterilise chopping boards, especially after preparing raw meat, poultry or seafood.

Proponents of raw food argue that cooking has a detrimental effect on foods and increases health risks. During cooking, the vitamin C contained in vegetables and fruits dissolves in the cooking water, and the food itself is degraded through oxidation. Peeling vegetables can also substantially reduce their vitamin C content: most of the vitamin C in potatoes, for example, is contained in the skin. Some scientists claim that diets that include large amounts of raw vegetables significantly reduce the risk of breast cancer.

According to some studies, more than 30 percent of cancer deaths may be prevented by making dietary changes. Some cancers may be caused by carcinogens in food generated during cooking processes, although it is often difficult to identify the specific dietary components responsible for increased cancer risk. Many foods, such as beef and broccoli, contain low concentrations of both carcinogens and anti-carcinogens. Several studies published in recent decades indicate that cooking meat at high temperatures creates heterocyclic amines (HCAs), which are thought to increase cancer risk in humans. Microwaving meat before cooking may reduce HCAs by 90 percent. Grilling, barbecuing or smoking meat and fish increases the levels of carcinogenic polycyclic aromatic hydrocarbons (PAHs). Baking, grilling or broiling food, especially starchy foods, until a crust forms, generates significant concentrations of acrylamide, a possible carcinogen.

Heating sugars with proteins or fats can produce substances that have been linked to ageing, diabetes and obesity. Deep-fried foods may contain high levels of trans-fats, which are known to increase the risk of heart disease.

Source: Various online resources