Ascorbic acid is an organic compound with formula C
6H
8O
6, originally called hexuronic acid. It is a white solid, but impure samples can appear yellowish. It dissolves freely in water to give mildly acidic solutions. It is a mild reducing agent.
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants are frequently added to industrial products, such as polymers, fuels, and lubricants, to extend their usable lifetimes. Foods are also treated with antioxidants to forestall spoilage, in particular the rancidification of oils and fats. In cells, antioxidants such as glutathione, mycothiol, or bacillithiol, and enzyme systems like superoxide dismutase, can prevent damage from oxidative stress.
A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or by undesirable chemical changes. In general, preservation is implemented in two modes, chemical and physical. Chemical preservation entails adding chemical compounds to the product. Physical preservation entails processes such as refrigeration or drying. Preservative food additives reduce the risk of foodborne infections, decrease microbial spoilage, and preserve fresh attributes and nutritional quality. Some physical techniques for food preservation include dehydration, UV-C radiation, freeze-drying, and refrigeration. Chemical preservation and physical preservation techniques are sometimes combined.
Vitamin C is a water-soluble vitamin found in citrus and other fruits, berries and vegetables. It is also a generic prescription medication and in some countries is sold as a non-prescription dietary supplement. As a therapy, it is used to prevent and treat scurvy, a disease caused by vitamin C deficiency.
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.
Rancidification is the process of complete or incomplete autoxidation or hydrolysis of fats and oils when exposed to air, light, moisture, or bacterial action, producing short-chain aldehydes, ketones and free fatty acids.
The nitrite ion has the chemical formula NO−
2. Nitrite is widely used throughout chemical and pharmaceutical industries. The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name nitrite also refers to organic compounds having the –ONO group, which are esters of nitrous acid.
Nitrosamines are organic compounds produced by industrial processes.
The Japp–Klingemann reaction is a chemical reaction used to synthesize hydrazones from β-keto-acids and aryl diazonium salts. The reaction is named after the chemists Francis Robert Japp and Felix Klingemann.
L-Gulonolactone oxidase is an enzyme that produces vitamin C. It is expressed in most mammals, but is non-functional in Haplorrhini, in some bats, and in guinea pigs. It catalyzes the reaction of L-gulono-1,4-lactone with oxygen to form L-xylo-hex-3-gulonolactone (2-keto-gulono-γ-lactone) and hydrogen peroxide. It uses FAD as a cofactor. The L-xylo-hex-3-gulonolactone then converts to ascorbic acid spontaneously, without enzymatic action. The structure of L-gulonolactone oxidase in rats helps identify characteristics of this enzyme.
Sodium erythorbate (C6H7NaO6) is a food additive used predominantly in meats, poultry, and soft drinks. Chemically, it is the sodium salt of erythorbic acid.
The Reed reaction is a chemical reaction that utilizes light to oxidize hydrocarbons to alkylsulfonyl chlorides. This reaction is employed in modifying polyethylene to give chlorosulfonated polyethylene (CSPE), which is noted for its toughness.
The Rosenmund reduction is a hydrogenation process in which an acyl chloride is selectively reduced to an aldehyde. The reaction was named after Karl Wilhelm Rosenmund, who first reported it in 1918.
Chlorobutanol (trichloro-2-methyl-2-propanol) is an organic compound with the formula CCl3C(OH)(CH3)2. The compound is an example of a chlorohydrin. The compound is a preservative, sedative, hypnotic and weak local anesthetic similar in nature to chloral hydrate. It has antibacterial and antifungal properties. Chlorobutanol is typically used at a concentration of 0.5% where it lends long term stability to multi-ingredient formulations. However, it retains antimicrobial activity at 0.05% in water. Chlorobutanol has been used in anesthesia and euthanasia of invertebrates and fishes. It is a white, volatile solid with a camphor-like odor.
The Schotten–Baumann reaction is a method to synthesize amides from amines and acid chlorides:
The Reichstein process in chemistry is a combined chemical and microbial method for the production of ascorbic acid from D-glucose that takes place in several steps. This process was devised by Nobel Prize winner Tadeusz Reichstein and his colleagues in 1933 while working in the laboratory of the ETH in Zürich.
The Fiesselmann thiophene synthesis is a name reaction in organic chemistry that allows for the generation of 3-hydroxy-2-thiophenecarboxylic acid derivatives from α,β-acetylenic esters with thioglycolic acid and its derivatives under the presence of a base. The reaction was developed by Hans Fiesselmann in the 1950s.
In biochemistry, nitrosamines are a class of compounds that can form during food digestion. The presence of their precursors, nitrites, in cured meats, is controversial, because of a small connection to cancer risk.
