Cooking, cookery, or culinary arts is the art,
science
Science is a systematic endeavor that Scientific method, builds and organizes knowledge in the form of Testability, testable explanations and predictions about the universe.
Science may be as old as the human species, and some of the earli ...
and craft of using
heat
In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is ...
to
prepare food for consumption. Cooking techniques and ingredients vary widely, from grilling food over an open
fire
Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products.
At a certain point in the combustion reaction, called the ignition ...
to using
electric stoves, to
baking
Baking is a method of preparing food that uses dry heat, typically in an oven, but can also be done in hot ashes, or on hot stones. The most common baked item is bread but many other types of foods can be baked. Heat is gradually transferre ...
in various types of
oven
upA double oven
A ceramic oven
An oven is a tool which is used to expose materials to a hot environment. Ovens contain a hollow chamber and provide a means of heating the chamber in a controlled way. In use since antiquity, they have been use ...
s, reflecting local conditions.
Types of cooking also depend on the skill levels and training of the
cooks. Cooking is done both by people in their own dwellings and by professional cooks and
chef
A chef is a trained professional cook and tradesman who is proficient in all aspects of food preparation, often focusing on a particular cuisine. The word "chef" is derived from the term ''chef de cuisine'' (), the director or head of a k ...
s in
restaurants and other food establishments.
Preparing food with heat or fire is an activity unique to
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
s. Archeological evidence of cooking fires from at least 300,000 years ago exists, but some estimate that humans started cooking up to 2 million years ago.
The expansion of
agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled peop ...
,
commerce
Commerce is the large-scale organized system of activities, functions, procedures and institutions directly and indirectly related to the exchange (buying and selling) of goods and services among two or more parties within local, regional, natio ...
,
trade
Trade involves the transfer of goods and services from one person or entity to another, often in exchange for money. Economists refer to a system or network that allows trade as a market.
An early form of trade, barter, saw the direct exch ...
, and
transport
Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land ( rail and road), water, cable, pipel ...
ation between
civilization
A civilization (or civilisation) is any complex society characterized by the development of a state, social stratification, urbanization, and symbolic systems of communication beyond natural spoken language (namely, a writing system).
C ...
s in different regions offered cooks many new ingredients. New inventions and technologies, such as the invention of
pottery
Pottery is the process and the products of forming vessels and other objects with clay and other ceramic materials, which are fired at high temperatures to give them a hard and durable form. Major types include earthenware, stoneware and po ...
for holding and
boiling
Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. T ...
of
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...
, expanded cooking techniques. Some modern cooks apply advanced scientific techniques to food preparation to further enhance the
flavor of the dish served.
History
Phylogenetic analysis
In biology
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that pro ...
suggests that early hominids may have adopted cooking 1.8 million to 2.3 million years ago.
Re-analysis of burnt bone fragments and plant ashes from the
Wonderwerk Cave
Wonderwerk Cave is an archaeological site, formed originally as an ancient solution cavity in dolomite rocks of the Kuruman Hills, situated between Danielskuil and Kuruman in the Northern Cape Province, South Africa. It is a National Heritage ...
in South Africa has provided evidence supporting
control of fire by early humans by 1 million years ago.
In his seminal work ''
Catching Fire: How Cooking Made Us Human'',
Richard Wrangham
Richard Walter Wrangham (born 1948) is an English anthropologist and primatologist; he is Professor of Biological Anthropology at Harvard University. His research and writing have involved ape behavior, human evolution, violence, and cooking.
...
suggested that evolution of bipedalism and a large cranial capacity meant that early ''
Homo erectus
''Homo erectus'' (; meaning " upright man") is an extinct species of archaic human from the Pleistocene, with its earliest occurrence about 2 million years ago. Several human species, such as ''H. heidelbergensis'' and ''H. antecessor' ...
'' regularly cooked food
However, unequivocal evidence in the archaeological record for the controlled use of fire begins at 400,000 BCE, long after
Homo erectus
''Homo erectus'' (; meaning " upright man") is an extinct species of archaic human from the Pleistocene, with its earliest occurrence about 2 million years ago. Several human species, such as ''H. heidelbergensis'' and ''H. antecessor' ...
.
Archaeological evidence from 300,000 years ago, in the form of ancient hearths,
earth oven
An earth oven, ground oven or cooking pit is one of the simplest and most ancient cooking structures. At its most basic, an earth oven is a pit in the ground used to trap heat and bake, smoke, or steam food. Earth ovens have been used in many pl ...
s, burnt animal bones, and
flint
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Flint was widely used historically to make stone tools and sta ...
, are found across Europe and the Middle East.
Anthropologists think that widespread cooking fires began about 250,000 years ago when
hearth
A hearth () is the place in a home where a fire is or was traditionally kept for home heating and for cooking, usually constituted by at least a horizontal hearthstone and often enclosed to varying degrees by any combination of reredos (a low, ...
s first appeared.
Recently, the earliest hearths have been reported to be at least 790,000 years old.
Communication between the
Old World
The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by th ...
and the
New World
The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. ...
in the
Columbian Exchange
The Columbian exchange, also known as the Columbian interchange, was the widespread transfer of plants, animals, precious metals, commodities, culture, human populations, technology, diseases, and ideas between the New World (the Americas) in ...
influenced the history of cooking. The movement of foods across the Atlantic from the New World, such as
potato
The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae.
Wild potato species can be found from the southern Un ...
es,
tomato
The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word , ...
es,
maize
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn ( North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. ...
,
bean
A bean is the seed of several plants in the family Fabaceae, which are used as vegetables for human or animal food. They can be cooked in many different ways, including boiling, frying, and baking, and are used in many traditional dishes t ...
s,
bell pepper
The bell pepper (also known as paprika, sweet pepper, pepper, or capsicum ) is the fruit of plants in the Grossum Group of the species ''Capsicum annuum''. Cultivars of the plant produce fruits in different colors, including red, yellow, orang ...
,
chili pepper
Chili peppers (also chile, chile pepper, chilli pepper, or chilli), from Nahuatl '' chīlli'' (), are varieties of the berry-fruit of plants from the genus '' Capsicum'', which are members of the nightshade family Solanaceae, cultivated for ...
,
vanilla
Vanilla is a spice derived from orchids of the genus ''Vanilla (genus), Vanilla'', primarily obtained from pods of the Mexican species, flat-leaved vanilla (''Vanilla planifolia, V. planifolia'').
Pollination is required to make the p ...
,
pumpkin
A pumpkin is a vernacular term for mature winter squash of species and varieties in the genus '' Cucurbita'' that has culinary and cultural significance but no agreed upon botanical or scientific meaning. The term ''pumpkin'' is sometimes u ...
,
cassava
''Manihot esculenta'', commonly called cassava (), manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America. Although a perennial plant, cassava is extensively cultivated a ...
,
avocado
The avocado (''Persea americana'') is a medium-sized, evergreen tree in the laurel family (Lauraceae). It is native to Americas, the Americas and was first domesticated by Mesoamerica, Mesoamerican tribes more than 5,000 years ago. Pre-Columb ...
,
peanut
The peanut (''Arachis hypogaea''), also known as the groundnut, goober (US), pindar (US) or monkey nut (UK), is a legume crop grown mainly for its edible Seed, seeds. It is widely grown in the tropics and subtropics, important to both small ...
,
pecan
The pecan (''Carya illinoinensis'') is a species of hickory native to the southern United States and northern Mexico in the region of the Mississippi River. The tree is cultivated for its seed in the southern United States, primarily in Georgia, ...
,
cashew
The cashew tree (''Anacardium occidentale'') is a tropical evergreen tree native to South America in the genus '' Anacardium'' that produces the cashew seed and the cashew apple accessory fruit. The tree can grow as tall as , but the dwarf c ...
,
pineapple
The pineapple (''Ananas comosus'') is a tropical plant with an edible fruit; it is the most economically significant plant in the family Bromeliaceae. The pineapple is indigenous to South America, where it has been cultivated for many centurie ...
,
blueberry,
sunflower,
chocolate
Chocolate is a food made from roasted and ground cacao seed kernels that is available as a liquid, solid, or paste, either on its own or as a flavoring agent in other foods. Cacao has been consumed in some form since at least the Olmec civil ...
,
gourd
Gourds include the fruits of some flowering plant species in the family Cucurbitaceae, particularly '' Cucurbita'' and '' Lagenaria''. The term refers to a number of species and subspecies, many with hard shells, and some without. One of the e ...
s, and
squash, had a profound effect on Old World cooking. The movement of foods across the Atlantic from the Old World, such as
cattle
Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Adult females are referred to as cows and adult ...
,
sheep
Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus ''Ovis'', in everyday usage it almost always refers to domesticated sh ...
,
pigs,
wheat
Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeolog ...
,
oat
The oat (''Avena sativa''), sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural, unlike other cereals and pseudocereals). While oats are suitable for human co ...
s,
barley
Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley ...
,
rice
Rice is the seed of the grass species '' Oryza sativa'' (Asian rice) or less commonly '' Oryza glaberrima'' (African rice). The name wild rice is usually used for species of the genera '' Zizania'' and ''Porteresia'', both wild and domestica ...
,
apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus '' Malus''. The tree originated in Central Asia, where its wild ances ...
s,
pear
Pears are fruits produced and consumed around the world, growing on a tree and harvested in the Northern Hemisphere in late summer into October. The pear tree and shrub are a species of genus ''Pyrus'' , in the family Rosaceae, bearing the p ...
s,
peas,
chickpea
The chickpea or chick pea (''Cicer arietinum'') is an annual legume of the family Fabaceae, subfamily Faboideae. Its different types are variously known as gram" or Bengal gram, garbanzo or garbanzo bean, or Egyptian pea. Chickpea seeds are hi ...
s,
green bean
Green beans are young, unripe fruits of various cultivars of the common bean ('' Phaseolus vulgaris''), although immature or young pods of the runner bean ('' Phaseolus coccineus''), yardlong bean ( ''Vigna unguiculata'' subsp. ''sesquipedali ...
s,
mustard, and
carrots, similarly changed New World cooking.
In the seventeenth and eighteenth centuries, food was a classic marker of identity in Europe. In the nineteenth-century "Age of
Nationalism
Nationalism is an idea and movement that holds that the nation should be congruent with the State (polity), state. As a movement, nationalism tends to promote the interests of a particular nation (as in a in-group and out-group, group of peo ...
" cuisine became a defining symbol of national identity.
The
Industrial Revolution
The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
brought mass-production, mass-marketing, and standardization of food. Factories processed, preserved, canned, and packaged a wide variety of foods, and processed cereals quickly became a defining feature of the American breakfast. In the 1920s,
freezing methods,
cafeteria
A cafeteria, sometimes called a canteen outside the U.S., is a type of food service location in which there is little or no waiting staff table service, whether a restaurant or within an institution such as a large office building or sc ...
s, and
fast food restaurant
A fast-food restaurant, also known as a quick-service restaurant (QSR) within the industry, is a specific type of restaurant that serves fast-food cuisine and has minimal table service. The food served in fast-food restaurants is typical ...
s emerged.
Ingredients
Most ingredients in cooking are derived from
living organisms
In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and fungi; ...
. 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 kinds of
fungi
A fungus (plural, : fungi or funguses) is any member of the group of Eukaryote, eukaryotic organisms that includes microorganisms such as yeasts and Mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified ...
. Cooks also use
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...
and
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ...
s such as
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quanti ...
. Cooks can also use
wine
Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are ...
or
spirits.
Naturally occurring ingredients contain various amounts of molecules called ''
proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respondi ...
'', ''
carbohydrate
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or ...
s'' and ''
fats''. They also contain water and minerals. Cooking involves a manipulation of the chemical properties of these molecules.
Carbohydrates
Carbohydrates include the common sugar,
sucrose
Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula .
For human consumption, sucrose is extracted and refi ...
(table sugar), a
disaccharide
A disaccharide (also called a double sugar or ''biose'') is the sugar formed when two monosaccharides are joined by glycosidic linkage. Like monosaccharides, disaccharides are simple sugars soluble in water. Three common examples are sucrose, ...
, and such simple sugars as
glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, usi ...
(made by enzymatic splitting of sucrose) and
fructose
Fructose, or fruit sugar, is a ketonic simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorb ...
(from fruit), and
starch
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...
es from sources such as cereal flour, rice,
arrowroot
Arrowroot is a starch obtained from the rhizomes (rootstock) of several tropical plants, traditionally ''Maranta arundinacea'', but also Florida arrowroot from ''Zamia integrifolia'', and tapioca from cassava (''Manihot esculenta''), which is oft ...
and potato.
The interaction of heat and carbohydrate is complex.
Long-chain sugars such as
starch
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...
tend to break down into more digestible
simpler sugars. If the sugars are heated so that all water of
crystallisation is driven off,
caramelization
Caramelization is a process of browning of sugar used extensively in cooking for the resulting sweet nutty flavor and brown color. The brown colors are produced by three groups of polymers: caramelans (C24H36O18), caramelens (C36H50O25), and ...
starts, with the sugar undergoing thermal decomposition with the formation of
carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes ...
, and other breakdown products producing
caramel
Caramel ( or ) is an orange-brown confectionery product made by heating a range of sugars. It can be used as a flavoring in puddings and desserts, as a filling in bonbons, or as a topping for ice cream and custard.
The process of caramelizat ...
. Similarly, the heating of sugars and proteins causes the
Maillard reaction
The Maillard reaction ( ; ) is a chemical reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. Seared steaks, fried dumplings, cookies and other kinds of biscuits, breads, toasted marshmallows, and m ...
, a basic flavor-enhancing technique.
An
emulsion
An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Althou ...
of starch with fat or water can, when gently heated, provide thickening to the dish being cooked. In
European cooking, a mixture of butter and flour called a
roux
Roux () is a mixture of flour and fat cooked together and used to thicken sauces. Roux is typically made from equal parts of flour and fat by weight. The flour is added to the melted fat or Cooking oil, oil on the stove top, blended until smoo ...
is used to thicken liquids to make stews or sauces. In Asian cooking, a similar effect is obtained from a mixture of rice or
corn starch
Corn starch, maize starch, or cornflour (British English) is the starch derived from corn (maize) grain. The starch is obtained from the endosperm of the kernel. Corn starch is a common food ingredient, often used to thicken sauces or soup ...
and water. These techniques rely on the properties of starches to create simpler mucilaginous
saccharide
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or m ...
s during cooking, which causes the familiar thickening of
sauce
In cooking, a sauce is a liquid, cream, or semi-solid food, served on or used in preparing other foods. Most sauces are not normally consumed by themselves; they add flavor, moisture, and visual appeal to a dish. ''Sauce'' is a French word t ...
s. This thickening will break down, however, under additional heat.
Fats
Types of fat include
vegetable oil
Vegetable oils, or vegetable fats, are oils extracted from seeds or from other parts of fruits. Like animal fats, vegetable fats are ''mixtures'' of triglycerides. Soybean oil, grape seed oil, and cocoa butter are examples of seed oils, ...
s, animal products such as butter and
lard
Lard is a semi-solid white fat product obtained by rendering the fatty tissue of a pig.[Lard]
entry in the ...
, as well as fats from grains, including
maize
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn ( North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. ...
and
flax
Flax, also known as common flax or linseed, is a flowering plant, ''Linum usitatissimum'', in the family Linaceae. It is cultivated as a food and fiber crop in regions of the world with temperate climates. Textiles made from flax are known i ...
oils. Fats are used in a number of ways in cooking and baking. To prepare
stir fries,
grilled cheese
A grilled cheese (sometimes known as a toasted sandwich or cheese toastie) is a hot sandwich typically prepared by heating one or more slices of cheese between slices of bread, with a cooking fat such as butter, on a frying pan, griddle, or sandw ...
or
pancake
A pancake (or hotcake, griddlecake, or flapjack) is a flat cake, often thin and round, prepared from a starch-based batter that may contain eggs, milk and butter and cooked on a hot surface such as a griddle or frying pan, often frying wit ...
s, the pan or griddle is often coated with fat or oil. Fats are also used as an ingredient in baked goods such as cookies, cakes and pies. Fats can reach temperatures higher than the boiling point of water, and are often used to conduct high heat to other ingredients, such as in frying, deep frying or sautéing. Fats are used to add flavor to food (e.g., butter or bacon fat), prevent food from sticking to pans and create a desirable texture.
Proteins
Edible animal material, including
muscle
Skeletal muscles (commonly referred to as muscles) are Organ (biology), organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other ...
,
offal
Offal (), also called variety meats, pluck or organ meats, is the organs of a butchered animal. The word does not refer to a particular list of edible organs, which varies by culture and region, but usually excludes muscle. Offal may also ref ...
, milk,
eggs
Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...
and
egg white
Egg white is the clear liquid (also called the albumen or the glair/glaire) contained within an egg. In chickens it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms arou ...
s, contains substantial amounts of protein. Almost all vegetable matter (in particular
legume
A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock fo ...
s and
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...
s) also includes proteins, although generally in smaller amounts. Mushrooms have high protein content. Any of these may be sources of
essential amino acid
An essential amino acid, or indispensable amino acid, is an amino acid that cannot be synthesized from scratch by the organism fast enough to supply its demand, and must therefore come from the diet. Of the 21 amino acids common to all life form ...
s. When
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...
s are heated they become
denatured (unfolded) and change texture. In many cases, this causes the structure of the material to become softer or more
friable
Friability ( ), the condition of being friable, describes the tendency of a solid substance to break into smaller pieces under duress or contact, especially by rubbing. The opposite of friable is indurate.
Substances that are designated hazardous, ...
– meat becomes ''cooked'' and is more friable and less flexible. In some cases, proteins can form more rigid structures, such as the coagulation of
albumen
Egg white is the clear liquid (also called the albumen or the glair/glaire) contained within an egg. In chickens it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms arou ...
in egg whites. The formation of a relatively rigid but flexible matrix from egg white provides an important component in baking cakes, and also underpins many desserts based on
meringue
Meringue (, ; ) is a type of dessert or candy, often associated with Swiss, French, Polish and Italian cuisines, traditionally made from whipped egg whites and sugar, and occasionally an acidic ingredient such as lemon, vinegar, or cream ...
.
Water
Cooking often involves water and water-based liquids. These can be added in order to immerse the substances being cooked (this is typically done with water,
stock
In finance, stock (also capital stock) consists of all the shares by which ownership of a corporation or company is divided.Longman Business English Dictionary: "stock - ''especially AmE'' one of the shares into which ownership of a company ...
or wine). Alternatively, the foods themselves can release water. A favorite method of adding flavor to dishes is to save the liquid for use in other recipes. Liquids are so important to cooking that the name of the cooking method used is often based on how the liquid is combined with the food, as in
steaming
Steaming is a method of cooking using steam. This is often done with a food steamer, a kitchen appliance made specifically to cook food with steam, but food can also be steamed in a wok. In the American southwest, steam pits used for cooking hav ...
,
simmering
Simmering is a food preparation technique by which foods are cooked in hot liquids kept just below the boiling point of water (lower than ) and above poaching temperature (higher than ). To create a steady simmer, a liquid is brought to a boil ...
,
boiling
Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. T ...
,
braising
Braising (from the French word ''braiser'') is a combination-cooking method that uses both wet and dry heats: typically, the food is first browned at a high temperature, then simmered in a covered pot in cooking liquid (such as wine, broth, coco ...
and
blanching. Heating liquid in an open container results in rapidly increased
evaporation, which
concentrate
A concentrate is a form of substance that has had the majority of its base component (in the case of a liquid: the solvent) removed. Typically, this will be the removal of water from a solution or suspension, such as the removal of water from fru ...
s the remaining
flavor and ingredients – this is a critical component of both
stewing
A stew is a combination of solid food ingredients that have been cooked in liquid and served in the resultant gravy. A stew needs to have raw ingredients added to the gravy. Ingredients in a stew can include any combination of vegetables and ...
and sauce making.
Vitamins and minerals
Vitamins and minerals are required for normal
metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...
; and what the body cannot manufacture itself must come from external sources. Vitamins come from several sources including fresh fruit and vegetables (
Vitamin C
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) a ...
), carrots,
liver
The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...
(
Vitamin A
Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably ...
), cereal bran, bread, liver (B vitamins), fish liver oil (
Vitamin D
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 ...
) and fresh green vegetables (
Vitamin K
Vitamin K refers to structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-synthesis modification of certain proteins that are required for blood coagulat ...
). Many minerals are also essential in small quantities including iron,
calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...
,
magnesium
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...
,
sodium chloride
Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35 ...
and
sulfur
Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...
; and in very small quantities copper,
zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic t ...
and
selenium
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and telluriu ...
. The micronutrients, minerals, and vitamins in fruit and vegetables may be destroyed or eluted by cooking. Vitamin C is especially prone to oxidation during cooking and may be completely destroyed by protracted cooking.
The bioavailability of some vitamins such as
thiamin
Thiamine, also known as thiamin and vitamin B1, is a vitamin, an essential micronutrient, that cannot be made in the body. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosphorylated forms of thia ...
,
vitamin B6
Vitamin B6 is one of the B vitamins, and thus an essential nutrient. The term refers to a group of six chemically similar compounds, i.e., "vitamers", which can be interconverted in biological systems. Its active form, pyridoxal 5′-phosphat ...
,
niacin
Niacin, also known as nicotinic acid, is an organic compound and a form of vitamin B3, an essential human nutrient. It can be manufactured by plants and animals from the amino acid tryptophan. Niacin is obtained in the diet from a variet ...
,
folate
Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...
, and
carotenoid
Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, cor ...
s are increased with cooking by being freed from the food microstructure. Blanching or steaming vegetables is a way of minimizing vitamin and mineral loss in cooking.
Methods
There are very many methods of cooking, most of which have been known since antiquity. These include baking, roasting, frying, grilling, barbecuing, smoking, boiling, steaming and braising. A more recent innovation is microwaving. Various methods use differing levels of heat and moisture and vary in cooking time. The method chosen greatly affects the result because some foods are more appropriate to some methods than others. Some major hot cooking techniques include:
;Roasting
:
Roasting
Roasting is a cooking method that uses dry heat where hot air covers the food, cooking it evenly on all sides with temperatures of at least from an open flame, oven, or other heat source. Roasting can enhance the flavor through caramelizatio ...
–
Barbecuing
Barbecue or barbeque (informally BBQ in the UK, US, and Canada, barbie in Australia and braai in South Africa) is a term used with significant regional and national variations to describe various cooking methods that use live fire and smoke ...
–
Grilling
Grilling is a form of cooking that involves dry heat applied to the surface of food, commonly from above, below or from the side. Grilling usually involves a significant amount of direct, radiant heat, and tends to be used for cooking meat a ...
/
Broiling –
Rotisserie
Rotisserie, also known as spit-roasting, is a style of roasting where meat is skewered on a spit – a long solid rod used to hold food while it is being cooked over a fire in a fireplace or over a campfire, or roasted in an oven. This metho ...
–
Searing
Searing (or pan searing) is a technique used in grilling, baking, braising, roasting, sautéing, etc., in which the surface of the food (usually meat such as beef, poultry, pork, seafood) is cooked at high temperature until a browned crust ...
;Baking
:
Baking
Baking is a method of preparing food that uses dry heat, typically in an oven, but can also be done in hot ashes, or on hot stones. The most common baked item is bread but many other types of foods can be baked. Heat is gradually transferre ...
–
Baking Blind – Flashbaking
;Boiling
:
Boiling
Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. T ...
–
Blanching –
Braising
Braising (from the French word ''braiser'') is a combination-cooking method that uses both wet and dry heats: typically, the food is first browned at a high temperature, then simmered in a covered pot in cooking liquid (such as wine, broth, coco ...
–
Coddling –
Double steaming –
Infusion
Infusion is the process of extracting chemical compounds or flavors from plant material in a solvent such as water, oil or alcohol, by allowing the material to remain suspended in the solvent over time (a process often called steeping). An i ...
–
Poaching
Poaching has been defined as the illegal hunting or capturing of wild animals, usually associated with land use rights.
Poaching was once performed by impoverished peasants for subsistence purposes and to supplement meager diets. It was set ag ...
–
Pressure cooking –
Simmering
Simmering is a food preparation technique by which foods are cooked in hot liquids kept just below the boiling point of water (lower than ) and above poaching temperature (higher than ). To create a steady simmer, a liquid is brought to a boil ...
–
Smothering
Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can i ...
–
Steaming
Steaming is a method of cooking using steam. This is often done with a food steamer, a kitchen appliance made specifically to cook food with steam, but food can also be steamed in a wok. In the American southwest, steam pits used for cooking hav ...
–
Steeping
Steeping is the soaking of an organic solid, such as leaves, in a liquid (usually water) to extract flavours or to soften it. The specific process of teas being prepared for drinking by leaving the leaves in heated water to release the flavour ...
–
Stewing
A stew is a combination of solid food ingredients that have been cooked in liquid and served in the resultant gravy. A stew needs to have raw ingredients added to the gravy. Ingredients in a stew can include any combination of vegetables and ...
–
Stone boiling
Stone boiling is a moist-heat cooking method. It involves placing heated rocks into a water-filled container to heat the liquid to the point where it can be used to cook. This method of food preparation is a fuel-intensive process and it often requ ...
–
Vacuum flask cooking
;Frying
:
Fry –
Air frying
An air fryer is a small countertop convection oven designed to simulate deep frying without submerging the food in oil. A fan circulates hot air at high speed, producing a crisp layer via browning reactions such as the Maillard reaction. Some pr ...
—
Deep frying
Deep frying (also referred to as deep fat frying) is a cooking method in which food is submerged in hot fat, traditionally lard but today most commonly oil, as opposed to the shallow oil used in conventional frying done in a frying pan. No ...
–
Gentle frying
Gentle frying or low-temperature frying is an oil- or fat-based cooking method used for relatively fragile or starchy foods. While gentle frying is most notably used to cook fried eggs, it is also used for delicate fish, tender cuts of meat, sausa ...
-
Hot salt frying –
Hot sand frying –
Pan frying
Pan frying or pan-frying is a form of frying food characterized by the use of minimal cooking oil or fat (compared to shallow frying or deep frying), typically using just enough to lubricate the pan. In the case of a greasy food such as bacon, ...
–
Pressure frying –
Sautéing
Sautéing or sauteing (, ; in reference to tossing while cooking) is a method of cooking that uses a relatively small amount of oil or fat in a shallow pan over relatively high heat. Various sauté methods exist.
Description
Ingredients for ...
–
Shallow frying
Shallow frying is a hot oil-based cooking technique. It is typically used to prepare portion-sized cuts of meat, fish, potatoes and patties such as fritters. Shallow frying can also be used to cook vegetables.
Technique
It is a medium-high to ...
–
Stir frying
Stir frying () is a cooking technique in which ingredients are fried in a small amount of very hot oil while being stirred or tossed in a wok. The technique originated in China and in recent centuries has spread into other parts of Asia and ...
—
Vacuum frying
;Steaming
:
Steaming
Steaming is a method of cooking using steam. This is often done with a food steamer, a kitchen appliance made specifically to cook food with steam, but food can also be steamed in a wok. In the American southwest, steam pits used for cooking hav ...
works by boiling water continuously, causing it to vaporise into steam; the steam then carries heat to the nearby food, thus cooking the food. By many it is considered a healthy form of cooking, holding nutrients within the vegetable or meat being cooked.
:
En papillote – The food is put into a pouch and then baked, allowing its own moisture to steam the food.
;Smoking
:
Smoking
Smoking is a practice in which a substance is burned and the resulting smoke is typically breathed in to be tasted and absorbed into the bloodstream. Most commonly, the substance used is the dried leaves of the tobacco plant, which have bee ...
is the process of flavoring, cooking, or preserving food by exposing it to smoke from burning or smoldering material, most often wood.
Health and safety
Indoor air pollution
As of 2021, over 2.6 billion people cook using open fires or inefficient stoves using
kerosene
Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning " wax", and was reg ...
,
biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms biom ...
, and
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as stratum, rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen ...
as fuel. These cooking practices use fuels and technologies that produce high levels of household air pollution, causing 3.8 million premature deaths annually. Of these deaths, 27% are from
pneumonia
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severi ...
, 27% from
ischaemic heart disease
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pl ...
, 20% from
chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. The main symptoms include shortness of breath and a cough, which may or may not produce ...
, 18% from
stroke, and 8% from
lung cancer
Lung cancer, also known as lung carcinoma (since about 98–99% of all lung cancers are carcinomas), is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. Lung carcinomas derive from transformed, malign ...
. Women and young children are disproportionately affected, since they spend the most time near the hearth.
Security while cooking
Hazards while cooking can include
* Unseen slippery surfaces (such as from oil stains or water droplets)
* Cuts (1 percent of injuries in United States related to knives, ended in hospital admissions. In overall 400 000 injuries from knives are recorded in the US
* Burns or fires
To prevent those injuries there are protections such as cooking clothing, anti-slip shoes, fire extinguisher and more.
Food safety
Cooking can prevent many
foodborne illness
Foodborne illness (also foodborne disease and food poisoning) is any illness resulting from the spoilage of contaminated food by pathogenic bacteria, viruses, or parasites that contaminate food,
as well as prions (the agents of mad cow ...
es that would otherwise occur if the food is eaten raw. When heat is used in the preparation of food, it can kill or inactivate harmful organisms, such as bacteria and viruses, as well as various parasites such as
tapeworm
Eucestoda, commonly referred to as tapeworms, is the larger of the two subclasses of flatworms in the class Cestoda (the other subclass is Cestodaria). Larvae have six posterior hooks on the scolex (head), in contrast to the ten-hooked Cestod ...
s and ''
Toxoplasma gondii
''Toxoplasma gondii'' () is an obligate intracellular parasitic protozoan (specifically an apicomplexan) that causes toxoplasmosis. Found worldwide, ''T. gondii'' is capable of infecting virtually all warm-blooded animals, but felids, such ...
''.
Food poisoning
Foodborne illness (also foodborne disease and food poisoning) is any illness resulting from the spoilage of contaminated food by pathogenic bacteria, viruses, or parasites that contaminate food,
as well as prions (the agents of mad cow disea ...
and other illness from uncooked or poorly prepared food may be caused by bacteria such as
pathogenic strains of ''
Escherichia coli
''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Esc ...
'', ''
Salmonella typhimurium
''Salmonella enterica'' subsp. ''enterica'' is a subspecies of ''Salmonella enterica'', the rod-shaped, flagellated, aerobic, Gram-negative bacterium. Many of the pathogenic serovars of the ''S. enterica'' species are in this subspecies, includ ...
'' and ''
Campylobacter
''Campylobacter'' (meaning "curved bacteria") is a genus of Gram-negative bacteria. ''Campylobacter'' typically appear comma- or s-shaped, and are motile. Some ''Campylobacter'' species can infect humans, sometimes causing campylobacteriosis, a d ...
'', viruses such as
norovirus
Norovirus, sometimes referred to as the winter vomiting disease, is the most common cause of gastroenteritis. Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain. Fever or headaches may also occur. Symptoms usually deve ...
es, and
protozoa
Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histor ...
such as ''
Entamoeba histolytica
''Entamoeba histolytica'' is an anaerobic parasitic amoebozoan, part of the genus '' Entamoeba''. Predominantly infecting humans and other primates causing amoebiasis, ''E. histolytica'' is estimated to infect about 35-50 million people worldw ...
''. Bacteria, viruses and parasites may be introduced through salad, meat that is uncooked or done
rare, and unboiled water.
The
sterilizing effect of cooking depends on temperature, cooking time, and technique used. Some
food spoilage
Food spoilage is the process where a food product becomes unsuitable to ingest by the consumer. The cause of such a process is due to many outside factors as a side-effect of the type of product it is, as well as how the product is packaged and s ...
bacteria such as ''
Clostridium botulinum
''Clostridium botulinum'' is a Gram-positive, rod-shaped, anaerobic, spore-forming, motile bacterium with the ability to produce the neurotoxin botulinum.
The botulinum toxin can cause botulism, a severe flaccid paralytic disease in humans ...
'' or ''
Bacillus cereus
''Bacillus cereus'' is a Gram-positive rod-shaped bacterium commonly found in soil, food, and marine sponges. The specific name, ''cereus'', meaning "waxy" in Latin, refers to the appearance of colonies grown on blood agar. Some strains are ...
'' can form spores that survive boiling, which then
germinate
Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...
and regrow after the food has cooled. This makes it unsafe to reheat cooked food more than once.
Cooking increases the digestibility of many foods which are inedible or poisonous when raw. For example, raw cereal grains are hard to digest, while
kidney bean
The kidney bean is a variety of the common bean (''Phaseolus vulgaris''). It resembles a human kidney and thus is named after such. Red kidney beans should not be confused with other red beans, such as adzuki beans.
Classification
There are ...
s are toxic when raw or improperly cooked due to the presence of
phytohaemagglutinin
Phytohaemagglutinin (PHA, or phytohemagglutinin) is a lectin found in plants, especially certain legumes. PHA actually consists of two closely related proteins, called leucoagglutinin (PHA-L) and PHA-E. These proteins cause blood cells to clump ...
, which is inactivated by cooking for at least ten minutes at .
Food safety depends on the safe preparation, handling, and storage of food. Food spoilage bacteria proliferate in the "
Danger zone" temperature range from , food therefore should not be stored in this temperature range.
Washing of hands and surfaces, especially when handling different meats, and keeping raw food separate from cooked food to avoid cross-contamination, are good practices in food preparation. Foods prepared on plastic cutting boards may be less likely to harbor bacteria than wooden ones.
Washing and
disinfecting
A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than s ...
cutting boards, especially after use with raw meat, poultry, or seafood, reduces the risk of contamination.
Effects on nutritional content of food
Proponents of
raw foodism
Raw foodism, also known as rawism or a raw food diet, is the dietary practice of eating only or mostly food that is uncooked and unprocessed. Depending on the philosophy, or type of lifestyle and results desired, raw food diets may include a ...
argue that cooking food increases the risk of some of the detrimental effects on food or health. They point out that during cooking of vegetables and fruit containing
vitamin C
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) a ...
, the vitamin elutes into the cooking water and becomes degraded through oxidation. Peeling vegetables can also substantially reduce the vitamin C content, especially in the case of potatoes where most vitamin C is in the skin. However, research has shown that in the specific case of
carotenoid
Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, cor ...
s a greater proportion is absorbed from cooked vegetables than from raw vegetables.
German research in 2003 showed significant benefits in reducing breast cancer risk when large amounts of raw vegetable matter are included in the diet. The authors attribute some of this effect to heat-labile
phytonutrients.
Sulforaphane, a
glucosinolate
Glucosinolates are natural components of many pungent plants such as mustard, cabbage, and horseradish. The pungency of those plants is due to mustard oils produced from glucosinolates when the plant material is chewed, cut, or otherwise damage ...
breakdown product, which may be found in vegetables such as
broccoli
Broccoli (''Brassica oleracea'' var. ''italica'') is an edible green plant in the cabbage family (family Brassicaceae, genus ''Brassica'') whose large flowering head, stalk and small associated leaves are eaten as a vegetable. Broccoli is clas ...
, has been shown to be protective against
prostate cancer
Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that su ...
; however, much of it is destroyed when the vegetable is boiled. Although there has been some basic research on how
sulforaphane might exert beneficial effects in vivo, there is no high-quality evidence for its efficacy against human diseases.
The
USDA
The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...
has studied retention data for 16 vitamins, 8 minerals, and alcohol for approximately 290 foods for various cooking methods.
Carcinogens
In a human epidemiological analysis by
Richard Doll
Sir William Richard Shaboe Doll (28 October 1912 – 24 July 2005) was a British physician who became an epidemiologist in the mid-20th century and made important contributions to that discipline. He was a pioneer in research linking smoking ...
and
Richard Peto
Sir Richard Peto (born 14 May 1943) is an English statistician and epidemiologist who is Professor of Medical Statistics and Epidemiology at the University of Oxford, England.
Education
He attended Taunton's School in Southampton and subsequ ...
in 1981, diet was estimated to cause a large percentage of cancers. Studies suggest that around 32% of cancer deaths may be avoidable by changes to the diet. Some of these cancers may be caused by carcinogens in food generated during the cooking process, although it is often difficult to identify the specific components in diet that serve to increase cancer risk. Many foods, such as
beefsteak
A beefsteak, often called just steak, is a flat cut of beef with parallel faces, usually cut perpendicular to the muscle fibers. In common restaurant service a single serving has a raw mass ranging from . Beef steaks are usually grilled, ...
and broccoli, contain low concentrations of both
carcinogen
A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive subst ...
s and
anticarcinogen An anticarcinogen (also known as a carcinopreventive agent) is a substance that counteracts the effects of a carcinogen or inhibits the development of cancer. Anticarcinogens are different from anticarcinoma agents (also known as anticancer or ant ...
s.
Several studies published since 1990 indicate that cooking meat at high temperature creates
heterocyclic amines (HCAs), which are thought to increase cancer risk in humans. Researchers at the
National Cancer Institute
The National Cancer Institute (NCI) coordinates the United States National Cancer Program and is part of the National Institutes of Health (NIH), which is one of eleven agencies that are part of the U.S. Department of Health and Human Services. T ...
found that human subjects who ate beef rare or medium-rare had less than one third the risk of stomach cancer than those who ate beef medium-well or well-done.
While avoiding meat or eating meat raw may be the only ways to avoid HCAs in meat fully, the National Cancer Institute states that cooking meat below creates "negligible amounts" of HCAs. Also,
microwaving
A microwave oven (commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces polar molecules in the food to rotate and produce th ...
meat before cooking may reduce HCAs by 90% by reducing the time needed for the meat to be cooked at high heat.
[ ]Nitrosamine
In organic chemistry, nitrosamines (or more formally ''N''-Nitrosamines) are organic compounds with the chemical structure , where R is usually an alkyl group. They feature a nitroso group () bonded to a deprotonated amine. Most nitrosamines a ...
s are found in some food, and may be produced by some cooking processes from proteins or from nitrites used as food preservatives; cured meat such as bacon has been found to be carcinogenic, with links to colon cancer. Ascorbate, which is added to cured meat, however, reduces nitrosamine formation.
Baking, grilling or broiling food, especially starchy foods, until a toasted crust is formed generates significant concentrations of acrylamide
Acrylamide (or acrylic amide) is an organic compound with the chemical formula CH2=CHC(O)NH2. It is a white odorless solid, soluble in water and several organic solvents. From the chemistry perspective, acrylamide is a vinyl-substituted primary a ...
. This discovery in 2002 led to international health concerns. Subsequent research has however found that it is not likely that the acrylamides in burnt or well-cooked food cause cancer in humans; Cancer Research UK
Cancer Research UK (CRUK) is the world's largest independent cancer research organization. It is registered as a charity in the United Kingdom and Isle of Man, and was formed on 4 February 2002 by the merger of The Cancer Research Campaign and t ...
categorizes the idea that burnt food causes cancer as a "myth".
Other health issues
Cooking dairy products may reduce a protective effect against colon cancer. Researchers at the University of Toronto
The University of Toronto (UToronto or U of T) is a public research university in Toronto, Ontario, Canada, located on the grounds that surround Queen's Park. It was founded by royal charter in 1827 as King's College, the first institu ...
suggest that ingesting uncooked or unpasteurized dairy product
Dairy products or milk products, also known as lacticinia, are food products made from (or containing) milk. The most common dairy animals are cow, water buffalo, nanny goat, and ewe. Dairy products include common grocery store food items in ...
s (see also Raw milk
Raw milk or unpasteurized milk is milk that has not been pasteurized, a process of heating liquid foods to kill pathogens for safe consumption and extending the shelf life.
Proponents of raw milk have asserted numerous supposed benefits to cons ...
) may reduce the risk of colorectal cancer. Mice and rats fed uncooked sucrose, casein, and beef tallow had one-third to one-fifth the incidence of microadenomas as the mice and rats fed the same ingredients cooked. This claim, however, is contentious. According to the Food and Drug Administration of the United States, health benefits claimed by raw milk advocates do not exist. "The small quantities of antibodies in milk are not absorbed in the human intestinal tract," says Barbara Ingham, PhD, associate professor and extension food scientist at the University of Wisconsin-Madison. "There is no scientific evidence that raw milk contains an anti-arthritis factor or that it enhances resistance to other diseases."
Heating sugars with proteins or fats can produce advanced glycation end products ("glycotoxins").
Deep fried food in restaurants may contain high level of trans fat
Trans fat, also called trans-unsaturated fatty acids, or trans fatty acids, is a type of unsaturated fat that naturally occurs in small amounts in meat and milk fat. It became widely produced as an unintentional byproduct in the industrial p ...
, which is known to increase levels of low-density lipoprotein
Low-density lipoprotein (LDL) is one of the five major groups of lipoprotein that transport all fat molecules around the body in extracellular water. These groups, from least dense to most dense, are chylomicrons (aka ULDL by the overall densi ...
that in turn may increase risk of heart diseases
Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, he ...
and other conditions. However, many fast food chains have now switched to trans-fat-free alternatives for deep-frying.
Scientific aspects
The scientific study of cooking has become known as molecular gastronomy
Molecular gastronomy is the scientific approach of nutrition from primarily the perspective of chemistry. The composition ( molecular structure), properties (mass, viscosity, etc) and transformations (chemical reactions, reactant products) o ...
. This is a subdiscipline of food science
Food science is the basic science and applied science of food; its scope starts at overlap with agricultural science and nutritional science and leads through the scientific aspects of food safety and food processing, informing the developme ...
concerning the physical and chemical transformations that occur during cooking.
Important contributions have been made by scientists, chefs and authors such as Hervé This
Hervé This (; born 5 June 1955 in Suresnes, Hauts-de-Seine, sometimes named Hervé This-Benckhard, or Hervé This vo Kientza) is a French physical chemist who works for the Institut National de la Recherche Agronomique at AgroParisTech, in Pari ...
(chemist), Nicholas Kurti
Nicholas Kurti, ( hu, Kürti Miklós) (14 May 1908 – 24 November 1998) was a Hungarian-born British physicist who lived in Oxford, UK, for most of his life.
Career
Born in Budapest, Kurti went to high school at the Minta Gymnasium, but due ...
(physicist), Peter Barham (physicist), Harold McGee (author), Shirley Corriher (biochemist, author), Robert Wolke (chemist, author.) It is different for the application of scientific knowledge to cooking, that is "molecular cooking"( (for the technique) or "molecular cuisine" (for a culinary style), for which chefs such as Raymond Blanc, Philippe and Christian Conticini, Ferran Adria, Heston Blumenthal
Heston Marc Blumenthal (; born 27 May 1966) is a British celebrity chef, TV personality and food writer. Blumenthal is regarded as a pioneer of multi-sensory cooking, food pairing and flavour encapsulation. He came to public attention with un ...
, Pierre Gagnaire
Pierre Gagnaire (born 9 April 1950 in Apinac, Loire) is a French chef, and the head chef and owner of the eponymous Pierre Gagnaire restaurant at 6 rue Balzac in Paris (in the 8th arrondissement). Gagnaire is an iconoclastic chef at the forefron ...
(chef).
Chemical processes central to cooking include hydrolysis (in particular beta elimination of pectins, during the thermal treatment of plant tissues), pyrolysis, and glycation reactions wrongly named Maillard reactions.
Cooking foods with heat depends on many factors — the specific heat
In thermodynamics, the specific heat capacity (symbol ) of a substance is the heat capacity of a sample of the substance divided by the mass of the sample, also sometimes referred to as massic heat capacity. Informally, it is the amount of he ...
of an object, thermal conductivity
The thermal conductivity of a material is a measure of its ability to conduct heat. It is commonly denoted by k, \lambda, or \kappa.
Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal ...
, and perhaps most significantly the difference in temperature between the two objects. Thermal diffusivity
In heat transfer analysis, thermal diffusivity is the thermal conductivity divided by density and specific heat capacity at constant pressure. It measures the rate of transfer of heat of a material from the hot end to the cold end. It has the SI ...
is the combination of specific heat, conductivity and density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematicall ...
that determines how long it will take for the food to reach a certain temperature.
Home-cooking and commercial cooking
Home cooking has traditionally been a process carried out informally in a home or around a communal fire, and can be enjoyed by all members of the family, although in many cultures women bear primary responsibility. Cooking is also often carried out outside of personal quarters, for example at restaurants, or schools. Bakeries were one of the earliest forms of cooking outside the home, and bakeries in the past often offered the cooking of pots of food provided by their customers as an additional service. In the present day, factory food preparation has become common, with many "ready-to-eat" as well as "ready-to-cook" foods being prepared and cooked in factories and home cooks using a mixture of scratch made, and factory made foods together to make a meal
A meal is an eating occasion that takes place at a certain time and includes consumption of food. The names used for specific meals in English vary, depending on the speaker's culture, the time of day, or the size of the meal.
Although they c ...
. The nutritional value of including more commercially prepared foods has been found to be inferior to home-made foods. Home-cooked meals tend to be healthier with fewer calories, and less saturated fat
A saturated fat is a type of fat in which the fatty acid chains have all single bonds. A fat known as a glyceride is made of two kinds of smaller molecules: a short glycerol backbone and fatty acids that each contain a long linear or branched ...
, cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membr ...
and sodium
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...
on a per calorie basis while providing more fiber
Fiber or fibre (from la, fibra, links=no) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorpora ...
, calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...
, and iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...
. The ingredients are also directly sourced, so there is control over authenticity, taste, and nutritional value. The superior nutritional quality of home-cooking could therefore play a role in preventing chronic disease
A chronic condition is a health condition or disease that is persistent or otherwise long-lasting in its effects or a disease that comes with time. The term ''chronic'' is often applied when the course of the disease lasts for more than three mon ...
. Cohort studies following the elderly over 10 years show that adults who cook their own meals have significantly lower mortality, even when controlling for confounding variables.
"Home-cooking" may be associated with comfort food
Comfort food is food that provides a nostalgic or sentimental value to someone, and may be characterized by its high caloric nature, high carbohydrate level, or simple preparation. The nostalgia may be specific to an individual, or it may appl ...
, and some commercially produced foods and restaurant meals are presented through advertising or packaging as having been "home-cooked", regardless of their actual origin. This trend began in the 1920s and is attributed to people in urban areas of the U.S. wanting homestyle food even though their schedules and smaller kitchens made cooking harder.
See also
* Carryover cooking Carryover cooking (sometimes referred to as resting) is when foods are halted from actively cooking and allowed to equilibrate under their own retained heat. Because foods such as meats are typically measured for cooking temperature near the cen ...
* Control of fire by early humans
* Cookbook
A cookbook or cookery book is a kitchen reference containing recipes.
Cookbooks may be general, or may specialize in a particular cuisine or category of food.
Recipes in cookbooks are organized in various ways: by course (appetizer, first cour ...
* Cooker
* Cooking weights and measures
In recipes, quantities of ingredients may be specified by mass (commonly called weight), by volume, or by count.
For most of history, most cookbooks did not specify quantities precisely, instead talking of "a nice leg of spring lamb", a "cupful" ...
* Cuisine
A cuisine is a style of cooking characterized by distinctive ingredients, techniques and dishes, and usually associated with a specific culture or geographic region. Regional food preparation techniques, customs, and ingredients combine to ...
* Culinary arts
* Culinary profession
Culinary arts are the cuisine arts of food preparation, cooking and presentation of food, usually in the form of meals. People working in this field – especially in establishments such as restaurants – are commonly called chefs or ...
* Cooking school
A cooking school is an institution devoted to education in the art and science of cooking and food preparation. There are many different types of cooking schools around the world, some devoted to training professional chefs, others aimed at amate ...
* Dishwashing
* Food and cooking hygiene
Food safety (or food hygiene) is used as a scientific method/discipline describing handling, preparation, and storage of food in ways that prevent food-borne illness. The occurrence of two or more cases of a similar illness resulting from t ...
* Food industry
The food industry is a complex, global network of diverse businesses that supplies most of the food consumed by the world's population. The food industry today has become highly diversified, with manufacturing ranging from small, traditional, ...
* Food preservation
Food preservation includes processes that make food more resistant to microorganism growth and slow the oxidation of fats. This slows down the decomposition and rancidification process. Food preservation may also include processes that inhi ...
* Food writing
Food writing is a genre of writing that focuses on food and includes works by food critics, food journalists, chefs and food historians.
Definition
Food writers regard food as a substance and a cultural phenomenon. John T. Edge, an American food ...
* Foodpairing
Foodpairing, or the non-registered trademarked term food pairing, is a method for identifying which foods go well together from a flavor standpoint. The method is based on the principle that foods combine well with one another when they share ke ...
* Gourmet Museum and Library
The Gourmet Museum and Library (french: Bibliothèque et musée de la Gourmandise) is a museum dedicated to the history of gastronomy, located in Hermalle-sous-Huy, province of Liège, Belgium.
Overview Library
It is the most important col ...
* High altitude cooking
* International food terms
The following list of international English food terms points out differences in food terminology between some different dialects of English:soft drinks in Scotland are actually called ginger ie can of ginger or a bottle of ginger.
List
Dige ...
* List of cooking appliances
This is a list of cooking appliances that are used for cooking foods.
Cooking appliances
* Air fryer
* Bachelor griller
* Barbecue grill
* Beehive oven
* Brasero (heater)
* Brazier
* Bread machine
* Burjiko
* Butane torch
* Chapati ...
* List of cooking techniques
* List of cuisines
A cuisine is a specific set of cooking traditions and practices, often associated with a specific culture or region. Each cuisine involves food preparation in a particular style, of food and drink of particular types, to produce individually con ...
* List of films about cooking
* List of food preparation utensils
A kitchen utensil is a hand-held, typically small tool that is designed for food-related functions. Food preparation utensils are a specific type of kitchen utensil, designed for use in the preparation of food. Some utensils are both food prepar ...
* List of ovens
This is a list of oven types. An oven is a thermally insulated chamber used for the heating, baking or drying of a substance, and most commonly used for cooking or for industrial processes (industrial oven). Kilns and furnaces are special-purpose ...
* List of stoves
This is a list of stoves. A stove is an enclosed space in which fuel is burned to provide heating, either to heat the space in which the stove is situated, or to heat the stove itself and items placed on it. Stoves are generally used for cooking ...
* Nutrition
Nutrition is the biochemical and physiological process by which an organism uses food to support its life. It provides organisms with nutrients, which can be metabolized to create energy and chemical structures. Failure to obtain sufficien ...
* Recipe
A recipe is a set of instructions that describes how to prepare or make something, especially a dish of prepared food. A sub-recipe or subrecipe is a recipe for an ingredient that will be called for in the instructions for the main recipe.
Hist ...
* Scented water
Scented water, odoriferous water,Baer, p. 43 or sweet water is a water with a sweet aromatic smell. It is made of flowers or herbs and is the precursor to the modern-day perfume. Scented waters are also used in making other products such as pom ...
* Spice
A spice is a seed, fruit, root, bark, or other plant substance primarily used for flavoring or coloring food. Spices are distinguished from herbs, which are the leaves, flowers, or stems of plants used for flavoring or as a garnish. Spices a ...
s
* Staple (cooking)
A staple food, food staple, or simply a staple, is a food that is eaten often and in such quantities that it constitutes a dominant portion of a standard diet for a given person or group of people, supplying a large fraction of energy needs and ...
References
External links
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{{Authority control
Articles containing video clips
Home economics
Survival skills