Food chemistry

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Food chemistry is the study of chemical processes and interactions of all biological and non-biological components of foods. [1] [2] The biological substances include such items as meat, poultry, lettuce, beer, milk as examples. It is similar to biochemistry in its main components such as carbohydrates, lipids, and protein, but it also includes areas such as water, vitamins, minerals, enzymes, food additives, flavors, and colors. This discipline also encompasses how products change under certain food processing techniques and ways either to enhance or to prevent them from happening. An example of enhancing a process would be to encourage fermentation of dairy products with microorganisms that convert lactose to lactic acid; an example of preventing a process would be stopping the browning on the surface of freshly cut apples using lemon juice or other acidulated water.

Contents

History of food chemistry

The scientific approach to food and nutrition arose with attention to agricultural chemistry in the works of J. G. Wallerius, Humphry Davy, and others. For example, Davy published Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture (1813) in the United Kingdom which would serve as a foundation for the profession worldwide, going into a fifth edition. Earlier work included that by Carl Wilhelm Scheele, who isolated malic acid from apples in 1785.

Some of the findings of Liebig on food chemistry were translated and published by Eben Horsford in Lowell Massachusetts in 1848. [3]

In 1874 the Society of Public Analysts was formed, with the aim of applying analytical methods to the benefit of the public. [4] Its early experiments were based on bread, milk, and wine.

It was also out of concern for the quality of the food supply, mainly food adulteration and contamination issues that would first stem from intentional contamination to later with chemical food additives by the 1950s. The development of colleges and universities worldwide, most notably in the United States, would expand food chemistry as well as research of the dietary substances, most notably the Single-grain experiment during 1907-11. Additional research by Harvey W. Wiley at the United States Department of Agriculture during the late 19th century would play a key factor in the creation of the United States Food and Drug Administration in 1906. The American Chemical Society established its Agricultural and Food Chemistry Division in 1908 while the Institute of Food Technologists established its Food Chemistry Division in 1995.

Food chemistry concepts are often drawn from rheology, theories of transport phenomena, physical and chemical thermodynamics, chemical bonds, and interaction forces, quantum mechanics and reaction kinetics, biopolymer science, colloidal interactions, nucleation, glass transitions and freezing/disordered or noncrystalline solids, and thus has Food Physical Chemistry as a foundation area. [5] [6]

Water in food systems

A major component of food is water, which can encompass anywhere from 50% in meat products to 95% in lettuce, cabbage, and tomato products. It is also an excellent place for bacterial growth and food spoilage if it is not properly processed. One way this is measured in food is by water activity which is very important in the shelf life of many foods during processing. One of the keys to food preservation in most instances is reduce the amount of water or alter the water's characteristics to enhance shelf-life. Such methods include dehydration, freezing, and refrigeration [7] [8] [9] [10] This field encompasses the "physiochemical principles of the reactions and conversions that occur during the manufacture, handling, and storage of foods". [11]

Carbohydrates

Sucrose: ordinary table sugar and probably the most familiar carbohydrate Saccharose.svg
Sucrose: ordinary table sugar and probably the most familiar carbohydrate

Comprising 75% of the biological world and 80% of all food intake for human consumption, the most common known human carbohydrate is sucrose [ citation needed ]. The simplest version of a carbohydrate is a monosaccharide which contains carbon, hydrogen, and oxygen in a 1:2:1 ratio under a general formula of CnH2nOn where n is a minimum of 3. Glucose and fructose are examples of monosaccharides. When combined in the way that the image to the right depicts, sucrose, one of the more common sugar products found in plants, is formed.

A chain of monosaccharides form to make a polysaccharide. Such polysaccharides include pectin, dextran, agar, and xanthan. [12] Some of these carbohydrate polysaccharides are accessible for digestion by human enzymes and mainly absorbed in the small intestine, whereas dietary fiber passes to the large intestine where some of these polysaccharides are fermented by the gastrointestinal microbiota. [13]

Sugar content is commonly measured in degrees brix.

Lipids

The term lipid comprises a diverse range of molecules and to some extent is a catchall for relatively water-insoluble or nonpolar compounds of biological origin, including waxes, fatty acids (including essential fatty acids), fatty-acid derived phospholipids, sphingolipids, glycolipids and terpenoids, such as retinoids and steroids. Some lipids are linear aliphatic molecules, while others have ring structures. Some are aromatic, while others are not. Some are flexible, while others are rigid.

Most lipids have some polar character in addition to being largely nonpolar. Generally, the bulk of their structure is nonpolar or hydrophobic ("water-fearing"), meaning that it does not interact well with polar solvents like water. Another part of their structure is polar or hydrophilic ("water-loving") and will tend to associate with polar solvents like water. This makes them amphiphilic molecules (having both hydrophobic and hydrophilic portions). In the case of cholesterol, the polar group is a mere -OH group (hydroxyl or alcohol).

Lipids in food include the oils of such grains as corn, soybean, from animal fats, and are parts of many foods such as milk, cheese, and meat. They also act as vitamin carriers.

Food proteins

Proteins comprise over 50% of the dry weight of an average living cell[ citation needed ][ clarification needed ] and are very complex macromolecules. They also play a fundamental role in the structure and function of cells. [14] Consisting mainly of carbon, nitrogen, hydrogen, oxygen, and some sulfur, they also may contain iron, copper, phosphorus, or zinc.

In food, proteins are essential for growth and survival, and requirements vary depending upon a person's age and physiology (e.g., pregnancy). Protein is commonly obtained from animal sources: eggs, milk, and meat. Nuts, grains and legumes provide vegetable sources of protein, and protein combining of vegetable sources is used to achieve complete protein nutritional quotas from vegetables.

Protein sensitivity as food allergy is detected with the ELISA test.

Enzymes

Enzymes are biochemical catalysts used in converting processes from one substance to another. They are also involved in reducing the amount of time and energy required to complete a chemical process. Many aspects of the food industry use catalysts, including baking, brewing, dairy, and fruit juices, to make cheese, beer, and bread.

Vitamins

Riboflavin (vitamin B2), water-soluble Riboflavin v2.svg
Riboflavin (vitamin B2), water-soluble

Vitamins are nutrients required in small amounts for essential metabolic reactions in the body. These are broken down in nutrition as either water-soluble (vitamin C) or fat-soluble (vitamin E). An adequate supply of vitamins can prevent diseases such as beriberi, anemia, and scurvy while an overdose of vitamins can produce nausea and vomiting or even death.

Minerals

Dietary minerals in foods are large and diverse with many required to function while other trace elements can be hazardous if consumed in excessive amounts. Bulk minerals with a Reference Daily Intake (RDI, formerly Recommended Daily Allowance (RDA)) of more than 200 mg/day are calcium, magnesium, and potassium while important trace minerals (RDI less than 200 mg/day) are copper, iron, and zinc. These are found in many foods, but can also be taken in dietary supplements.

Colour

Food colouring is added to change the colour of any food substance. It is mainly for sensory analysis purposes. It can be used to simulate the natural colour of a product as perceived by the customer, such as red dye (like FD&C Red No.40 Allura Red AC) to ketchup or to add unnatural colours to a product like Kellogg's Froot Loops. Caramel is a natural food dye; the industrial form, caramel colouring, is the most widely used food colouring and is found in foods from soft drinks to soy sauce, bread, and pickles.

Flavours

Flavour in food is important in how food smells and tastes to the consumer, especially in sensory analysis. Some of these products occur naturally like salt and sugar, but flavour chemists (called a "flavourist") develop many of these flavours for food products. Such artificial flavours include methyl salicylate which creates the wintergreen odor and lactic acid which gives milk a tart taste.

Food additives

Food additives are substances added to food for preserving flavours, or improving taste, look, smell and freshness. The processes are as old as adding vinegar for pickling or as an emulsifier for emulsion mixtures like mayonnaise. These are generally listed by "E number" in the European Union or GRAS ("generally recognized as safe") by the United States Food and Drug Administration.

See also

Related Research Articles

<span class="mw-page-title-main">Biochemistry</span> Study of chemical processes in living organisms

Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, and metabolism. Over the last decades of the 20th century, biochemistry has become successful at explaining living processes through these three disciplines. Almost all areas of the life sciences are being uncovered and developed through biochemical methodology and research. Biochemistry focuses on understanding the chemical basis which allows biological molecules to give rise to the processes that occur within living cells and between cells, in turn relating greatly to the understanding of tissues and organs as well as organism structure and function. Biochemistry is closely related to molecular biology, the study of the molecular mechanisms of biological phenomena.

<span class="mw-page-title-main">Carbohydrate</span> Organic compound that consists only of carbon, hydrogen, and oxygen

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 and thus with the empirical formula Cm(H2O)n, which does not mean the H has covalent bonds with O. However, not all carbohydrates conform to this precise stoichiometric definition, nor are all chemicals that do conform to this definition automatically classified as carbohydrates.

<span class="mw-page-title-main">Food additive</span> Substances added to food

Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives have been used for centuries as part of an effort to preserve food, for example vinegar (pickling), salt (salting), smoke (smoking), sugar (crystallization), etc. This allows for longer-lasting foods such as bacon, sweets or wines. With the advent of ultra-processed foods in the second half of the twentieth century, many additives have been introduced, of both natural and artificial origin. Food additives also include substances that may be introduced to food indirectly in the manufacturing process, through packaging, or during storage or transport.

Hydrolysis is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile.

<span class="mw-page-title-main">Lipid</span> Substance of biological origin that is soluble in nonpolar solvents

Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins, monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries, and in nanotechnology.

<span class="mw-page-title-main">Nutrition</span> Provision to cells and organisms to support life

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 the required amount of nutrients causes malnutrition. Nutritional science is the study of nutrition, though it typically emphasizes human nutrition.

<span class="mw-page-title-main">Polysaccharide</span> Long carbohydrate polymers such as starch, glycogen, cellulose, and chitin

Polysaccharides, or polycarbohydrates, are the most abundant carbohydrates found in food. They are long-chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with water (hydrolysis) using amylase enzymes as catalyst, which produces constituent sugars. They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch, glycogen and galactogen and structural polysaccharides such as hemicellulose and chitin.

<span class="mw-page-title-main">Pantothenic acid</span> Chemical compound

Pantothenic acid (vitamin B5) is a B vitamin and an essential nutrient. All animals need pantothenic acid in order to synthesize coenzyme A (CoA), which is essential for cellular energy production and for the synthesis and degradation of proteins, carbohydrates, and fats.

A nutrient is a substance used by an organism to survive, grow and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi and protists. Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures such as hair, scales, feathers, or exoskeletons. Some nutrients can be metabolically converted into smaller molecules in the process of releasing energy such as for carbohydrates, lipids, proteins and fermentation products leading to end-products of water and carbon dioxide. All organisms require water. Essential nutrients for animals are the energy sources, some of the amino acids that are combined to create proteins, a subset of fatty acids, vitamins and certain minerals. Plants require more diverse minerals absorbed through roots, plus carbon dioxide and oxygen absorbed through leaves. Fungi live on dead or living organic matter and meet nutrient needs from their host.

<span class="mw-page-title-main">Human nutrition</span> Nutrients supporting human health

Human nutrition deals with the provision of essential nutrients in food that are necessary to support human life and good health. Poor nutrition is a chronic problem often linked to poverty, food security, or a poor understanding of nutritional requirements. Malnutrition and its consequences are large contributors to deaths, physical deformities, and disabilities worldwide. Good nutrition is necessary for children to grow physically and mentally, and for normal human biological development.

<span class="mw-page-title-main">Biomolecule</span> Molecule produced by a living organism

A biomolecule or biological molecule is loosely defined as a molecule produced by a living organism and essential to one or more typically biological processes. Biomolecules include large macromolecules such as proteins, carbohydrates, lipids, and nucleic acids, as well as small molecules such as vitamins and hormones. A general name for this class of material is biological materials. Biomolecules are an important element of living organisms, those biomolecules are often endogenous, produced within the organism but organisms usually need exogenous biomolecules, for example certain nutrients, to survive.

<span class="mw-page-title-main">Oligosaccharide</span> Saccharide polymer

An oligosaccharide is a saccharide polymer containing a small number of monosaccharides. Oligosaccharides can have many functions including cell recognition and cell adhesion.

<span class="mw-page-title-main">Palmitic acid</span> Chemical compound

Palmitic acid is a fatty acid with a 16-carbon chain. It is the most common saturated fatty acid found in animals, plants and microorganisms. Its chemical formula is CH3(CH2)14COOH, and its C:D ratio is 16:0. It is a major component of palm oil from the fruit of Elaeis guineensis, making up to 44% of total fats. Meats, cheeses, butter, and other dairy products also contain palmitic acid, amounting to 50–60% of total fats.

<span class="mw-page-title-main">Coffee bean</span> Seed of the coffee plant

A coffee bean is a seed from the Coffea plant and the source for coffee. It is the pit inside the red or purple fruit. This fruit is often referred to as a coffee cherry, and like the cherry, it is a fruit with a pit. Even though the coffee beans are not technically beans, they are referred to as such because of their resemblance to true beans. The fruits most commonly contain two stones with their flat sides together. A small percentage of cherries contain a single seed, called a "peaberry". Peaberries make up only around 10% to 15% of all coffee beans. It is a fairly common belief that they have more flavour than normal coffee beans. Like Brazil nuts and white rice, coffee beans consist mostly of endosperm.

<span class="mw-page-title-main">Thickening agent</span> Increases the viscosity of a liquid without altering its other properties

A thickening agent or thickener is a substance which can increase the viscosity of a liquid without substantially changing its other properties. Edible thickeners are commonly used to thicken sauces, soups, and puddings without altering their taste; thickeners are also used in paints, inks, explosives, and cosmetics.

<span class="mw-page-title-main">Milk substitute</span> Alternative substance that resembles milk

A milk substitute is any substance that resembles milk and can be used in the same ways as milk. Such substances may be variously known as non-dairy beverage, nut milk, grain milk, legume milk, mock milk and alternative milk.

Biomolecular engineering is the application of engineering principles and practices to the purposeful manipulation of molecules of biological origin. Biomolecular engineers integrate knowledge of biological processes with the core knowledge of chemical engineering in order to focus on molecular level solutions to issues and problems in the life sciences related to the environment, agriculture, energy, industry, food production, biotechnology and medicine.

Animal nutrition focuses on the dietary nutrients needs of animals, primarily those in agriculture and food production, but also in zoos, aquariums, and wildlife management.

Food physical chemistry is considered to be a branch of Food chemistry concerned with the study of both physical and chemical interactions in foods in terms of physical and chemical principles applied to food systems, as well as the applications of physical/chemical techniques and instrumentation for the study of foods. This field encompasses the "physiochemical principles of the reactions and conversions that occur during the manufacture, handling, and storage of foods."

<span class="mw-page-title-main">Pea protein</span> Food product and protein supplement derived from Pisum sativum

Pea protein is a food product and protein supplement derived and extracted from yellow and green split peas, Pisum sativum. It can be used as a dietary supplement to increase an individual's protein or other nutrient intake, or as a substitute for other food products. As a powder, it is used as an ingredient in food manufacturing, such as a thickener, foaming agent, or an emulsifier.

References

  1. ↑ John M. de Man.1999. Principles of Food Chemistry (Food Science Text Series), Springer Science, Third Edition
  2. ↑ John M. de Man. 2009. Food process engineering and technology, Academic Press, Elsevier: London and New York, 1st edn.
  3. ↑ Eben Horsford (editor) (1848) Liebig's Researches on the Chemistry of Food and the Motion of the Juices in the Animal Body, Lowell Massachusetts
  4. ↑ Proc. Soc. Analyt. Chem p. 234
  5. ↑ Pieter Walstra. 2003. Physical Chemistry Of Foods. Marcel Dekker, Inc.: New York, 873 pages
  6. ↑ Physical Chemistry Of Food Processes: Fundamental Aspects.1992.van Nostrand-Reinhold vol.1., 1st Edition,
  7. ↑ Pieter Walstra. 2003. Physical Chemistry Of Foods. Marcel Dekker, Inc.: New York, 873 pages
  8. ↑ Physical Chemistry Of Food Processes: Fundamental Aspects.1992.van Nostrand-Reinhold vol.1., 1st Edition,
  9. ↑ Henry G. Schwartzberg, Richard W. Hartel. 1992. Physical Chemistry of Foods. IFT Basic Symposium Series, Marcel Dekker, Inc.:New York, 793 pages
  10. ↑ Physical Chemistry of Food Processes, Advanced Techniques, Structures and Applications.1994. van Nostrand-Reinhold vols.1-2., 1st Edition, 998 pages; 3rd edn. Minuteman Press, 2010; vols. 2-3, fifth edition (in press)
  11. ↑ Pieter Walstra. 2003. Physical Chemistry Of Foods. Marcel Dekker, Inc.: New York, 873 pages
  12. ↑ Ostrowski, Matthew P.; La Rosa, Sabina Leanti; Kunath, Benoit J.; Robertson, Andrew; Pereira, Gabriel; Hagen, Live H.; Varghese, Neha J.; Qiu, Ling; Yao, Tianming; Flint, Gabrielle; Li, James; McDonald, Sean P.; Buttner, Duna; Pudlo, Nicholas A.; Schnizlein, Matthew K.; Young, Vincent B.; Brumer, Harry; Schmidt, Thomas M.; Terrapon, Nicolas; Lombard, Vincent; Henrissat, Bernard; Hamaker, Bruce; Eloe-Fadrosh, Emiley A.; Tripathi, Ashootosh; Pope, Phillip B.; Martens, Eric C. (April 2022). "Mechanistic insights into consumption of the food additive xanthan gum by the human gut microbiota". Nature Microbiology. 7 (4): 556–569. doi:10.1038/s41564-022-01093-0. hdl: 11250/3003739 . PMID   35365790. S2CID   247866305.
  13. ↑ Makki, Kassem; Deehan, Edward C.; Walter, Jens; Bäckhed, Fredrik (June 2018). "The Impact of Dietary Fiber on Gut Microbiota in Host Health and Disease". Cell Host & Microbe. 23 (6): 705–715. doi: 10.1016/j.chom.2018.05.012 . PMID   29902436. S2CID   49211123.
  14. ↑ Food and Nutrition Board of Institute of Medicine (2005) Dietary Reference Intakes for Protein and Amino Acids, page 685, from National Academies Press

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