Amino acids are the building blocks of life and are encoded by DNA. Enzymes and structural proteins are made of amino acids, and are used as precursors for other important biomolecules in the body. In addition, many different industries ranging from pharmaceuticals to the food industry rely on amino acids.
Obtaining essential amino acids through health and pharmaceuticals
Essential amino acids are amino acids that the body cannot produce itself, meaning an outside source is needed. They can be obtained through diet or supplementation. These amino acids are often introduced into the body in intravenous therapy, to help with the recovery of post-operative patients.
Many amino acids are used in food supplements to help with certain conditions and disorders. For example, tryptophan are used for sleep disorders, depression, ADHD, phenylketonuria, narcolepsy, and chronic fatigue syndrome.
Arginine is often used as an ingredient in toothpaste or other dental products to provide relief from sensitive teeth. Arginine is a mineral which acts in a similar way to dentin, an important regulator of tooth sensitivity. A diet composed of all the amino acids, carbohydrates, and vitamins is recommended for patients with a defective digestive system or inflammatory bowel disease
Essential amino acids in the food industry
Flavour enhancers
Several amino acids or their derivatives are used as flavour enhancers in foods. For example, glycine and alanine are used to heighten flavour and taste. Another example is monosodium glutamate (MSG), a derivative of glutamic acid, widely used in Asian dishes to intensify the flavour. MSG produces a different type of flavour called ‘umami’ which is vital to many dishes.
Preservatives
Amino acids are also commonly used as preservatives in food and drink. Fruit juices are often preserved with the use of cysteine as an antioxidant.
Tryptophan is also used with histidine as an antioxidant to preserve milk powder. Phenylalanine and aspartic acid are combined to produce the dipeptide aspartame. Aspartame is roughly 200 times as sweet as sucrose and is often used as a low-calorie alternative to artificial sweetener in soft drinks.
Increasing nutritional value
Some products are often supplemented with certain amino acids to increase their nutritional value. Many plant based products are deficient in certain amino acids which can be introduced to provide the consumer with extra nutrients to improve health. For example, bread can be enriched with lysine, and soy products can be enriched with methionine. Lysine, methionine, and glutamic acid are widely used in animal feeds.
Amino acids in the chemical industry
Many amino acids are used as precursors for chemicals used in various industries, such as pesticides and herbicides. For example, threonine can be used to produce herbicide azthreonam and glycine can be used to produce glyphosate, another herbicide.
Amino acids in the fitness industry
Several amino acids (leucine, valine, proline, alanine, cysteine, and isoleucine) are used in supplements for muscle growth and body building. Building muscle involves ingesting protein and amino acids that build up the proteins.
Industrial production of amino acids
Chemical synthesis
Amino acids can be produced by chemical synthesis, enzymatic catalysis, extraction from natural sources, or fermentation. Chemical synthesis is often used in industry for the mass production of specific amino acids. However, the major drawback of this technique is that it produces two forms of the amino acids called enantiomers which need to be separated before they can be used. This method can therefore only be used when the enantiomer of the amino acid is unimportant for the intended use.
Fermentation
Fermentation is currently only used for lysine and glutamic acid as certain mutant bacteria strains are needed which are difficult to produce. Glutamic acid can be modified with the addition of sodium hydroxide to produce monosodium glutamate.
Further Reading
How diet shapes gut microbiota and affects brain function