Biochemistry

Ascorbate oxidase acts on ascorbic acid, i.e. oxidizes it to dehydroascorbic acid. This enzyme is found in many higher plants. Contains copper as a functional group that changes its valency during catalysis. Due to its action, the destruction of vitamin C occurs during technological processing. Inhibitors of this enzyme are certain amino acids (glycine, cysteine, aspartic and glutamic acids), carboxylic and hydroxycarboxylic acids (oxalic, citric, tartaric), pectins, flavonoids and tannins, quercetin, anthocyanins, catechins. During the technological processing of products, ascorbate oxidase not only reduces the content of ascorbic acid, but also affects the color and aroma of juices. Catalase - oxidoreductase - dehydrogenates a hydrogen peroxide molecule to form water and atomic oxygen. It contains ferrinprotoporferin IX as a functional group. ’ The enzyme molecule contains four hemin groups, each of which is associated with a protein. Catalase is inhibited by substances that form complexes with the central iron atom, for example, cyanide, sulfide, azide, fluoride, CO, NO, cyanamide, etc. Found in all cells with an aerobic type of metabolism. In the food industry, its preparations are used from the liver and molds in those cases when hydrogen peroxide is first treated, and then it must be removed. For example, during pasteurization and sterilization of milk, while bleaching hair, skins, and disinfecting surgical material. Peroxidase promotes the breakdown of peroxides. Its composition, depending on the source^ contains either red or green hemin. Horseradish peroxidase is relatively stable when heated. Warming the enzyme at 85 °C for 30 minutes leads to the loss of only half of the activity. It is inhibited by salts of heavy metals. It is used to assess the quality of the pasteurization process. Its sufficiency is determined by the activity of this enzyme. When fermenting tea and tobacco, this enzyme contributes to the formation of colored and aromatic components. Lipoxygenase catalyzes the reaction: unsaturated fatty acid + O 2 — > unsaturated fatty acid peroxide. It is characterized by high specificity and acts only on unsaturated fatty acids in the cis form. Linoleic, linolenic and arachidonic acids are oxidized at the same rate. Contained in wheat, oilseeds, legumes, alfalfa, soy flour. In the processing of food products, lipoxygenase inhibitors are used, which interact with free radicals formed as intermediate products by the action of this enzyme on unsaturated fatty acids. This enzyme destroys carotene, aromatic compounds of products. It contributes to the burning of fats. When using lipoxygenesis in breadmaking, the color of the crumb improves and the volume of bread increases. Lipase refers to hydrolysis. It catalyzes the breakdown of glycerol esters and higher fatty acids. Moreover, the rate of cleavage depends on the chain length of fatty acids. The source for industrial lipase preparations is the pancreas, molds, 97