Animal application ascorbic acid

Keto-L-Gulonic acid (2-KLG) is the precursor for Vitamin C (L-Ascorbic acid). Vitamin C is used on a large scale as an antioxidant in food, animal feed, beverages, pharmaceutical formulations, and cosmetic applications. About one half of the vitamin C is used in vitamin supplements and multivitamin preparations, one quarter in food additives, 15 percent in beverages, and 10 percent in animal feed. When ascorbic acid is used in... 

L-Ascorbic acid is found in all living tissues, both animal and plant matter, and as such has been consumed by humans for thousands of years, thus giving encouragement that the compound is physiologically acceptable and safe. Furthermore, extensive testing of L-ascorbic acid prepared by chemical synthesis confirms its relative safety. Large-scale manufacture, coupled with high standards of purity and relatively low cost, makes application to food products economically feasible. 

ACTH has been measured by bioassay, receptor assay, or immunoassay. Most bioassays are based on the effects of ACTH on adrenocortical cells (e.g, the stimulation of steroidogenesis or depletion of ascorbic acid). Responses are usually observed in the adrenal glands of hypophysec-tomized animals in situ or in isolated adrenal cells in vivo. In genera these bio assays are expensive and difficult to perform and are Hmited to research laboratories. Receptor assays use solubilized binding proteins obtained from normal or neoplastic adrenocortical ceUs. Only biologically active ACTH is measured, and a 10-pg/mL detection limit has been reported in unextracted plasma. These assays have limited application in the clinical laboratory partly because of the complexity and lability of receptor preparations. 

In some countries, nicotinic acid is added to white wheat flour and to other cereal products. The complex with menadione bisulfite, which shows the activity of niacin and vitamin K, has been used in animal nutrition. Nicotinamide in combination with ascorbic acid is used as a meat colour stabiliser, but has not found wider application in the meat industry (under anaerobic conditions, metmyoglobin in raw meat is reduced back to myoglobin by enzymes that contain NAD as a cofactor). 

In the visual titration procedure a dilute solution of the dye is used to titrate the ascorbic acid in an acid extract of the tissue or vitamin source. A pink color that persists for 15 seconds after the addition of one drop of the indophenol reagent is taken as the end point of the titration. The application of this reagent is based upon the assumption that ascorbic add is the prindpal, or peihaps only, substance in add extracts of the vitamin sources that reduces indophenol at a pH of 1-1, which is essentially true for a condderable number of plant and animal tissue extracts. 

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