Ascorbic Acid Technology in Agricultural, Pharmaceutical, Food, and Industrial Applications

Abstract

Ascorbic acid, as well as its salts and esters, has many useful applications. In plants L-ascorbic acid has been reported to promote germination of seeds, growth of plants, and growth of roots on cuttings. Spraying of plants such as lettuce, celery, spinach, petunias, and roses with ascorbic acid or sodium ascorbate solutions enabled those plants to better withstand damage from ozone and smog exposure. Spraying tree or bush fruits with ascorbic acid solution synchronizes maturation and causes fruit to fall more easily in mechanical harvesting. In some instances ascorbic acid application has been cited to improve the defense mechnism of plants to attack by disease agents. Fish require a dietary source of vitamin C, without which they grow poorly and develop fracture dislocations of the spine, distortions of cartilage, and other deficiency signs. In some instances, ruminants and monogastric animals appear to benefit from administration of L-ascorbic acid under stress. Animals with viral disease, such as canine or feline distemper, have responded to treatment with high levels of ascorbic acid. Solid and liquid forms constitute a substantial pharmaceutical market for manufactured ascorbic acid. Tableting techniques have been devised to prepare a wide array of swallowable or chewable tablets with an assured vitamin C content after manufacture and prolonged storage. L-Ascorbic acid may be added to foods or food ingredients as a nutrient to fortify natural or fabricated foods having little or no vitamin C, to restore losses, and to standardize a given class of food products with a preselected quantity of the vitamin. Factors that must be considered with appropriate technology before adding ascorbic acid are the following: (i) cost of the specific food; (ii) convenience of use; (Hi) relationship of the food in question to normal food selection or to replacement or supplemental food products; (iv) stability of the vitamin in the food during shelf life and home preparation; (v) public health considerations; and (vi) special food needs, such as infant, geriatric, and military. In addition to serving as an added nutrient in food, L-ascorbic acid is often used as a processing aid or as a preservative in certain foods or food ingredients. Examples include preventing enzymatic browning of cut fruit, scavenging oxygen in beer, fruit, or vegetable products, inhibiting oxidative rancidity in frozen fish, stabilizing the color and flavor in cured meats, maturing of wheat flour and improving of dough, and acting as a reducing agent in wine. An extensive list of patents and scientific papers exists on proposed industrial uses of ascorbic acid. The greatest interest appears to be in the synthetic polymer industry, in photoprocessing, and in metal technology. Miscellaneous uses have been proposed in cosmetics, tobacco, fibers, preservation of blood, preservation of cut plants, cleaning agents, and in assay reagents.