GB712225A - Method of stabilizing fats and oils and fatty acids and compositions obtained thereby - Google Patents

Abstract

Fatty materials are made more stable against oxidation by washing them, in liquid form, with a polar solvent containing glycine and phosphoric acid dissolved therein, the solvent being immiscible with the fatty material, and then separating the solvent solution from the fatty material. An antioxidant for fatty material may then be added to the washed product, its effect being greatly enhanced by the washing treatment. The fatty materials may comprise animal, vegetable or synthetic fats and fatty oils and also fatty acids, the materials specified comprising lard, cottonseed oil, soybean oil, peanut oil, marine oils, coconut oil, and corn oil, as well as oleic acid and linoleic acid. The fatty materials are treated in liquid form at temperatures ranging from 50 DEG C. to 95 DEG C., preferably for 3 to 30 minutes. The polar solvents specified comprise water, glycerine and aqueous alcohols such as methanol, ethanol or isopropanol. The washing solution preferably includes both the glycine and phosphoric acid in a single solution, but separate solutions may be used. The glycine and phosphoric acid are preferably in equal proportions; the phosphoric acid should not be more than twice the weight of glycine. Concentrations of 0.01 to 0.5 per cent. by weight of each in the washing solution are adequate. Materials furnishing glycine or phosphoric acid under the conditions described may be used; the glycine may be present as a glycine salt, such as the sodium salt, or as an amino acid composition containing glycine obtained by hydrolysis of protein matter, such as soyabean meal; the phosphoric acid may be added as the sodium salt. Usual washing procedures may be used with agitation means. The fatty material may be separated from the washing solution by settling, centrifuging &c. The antioxidants specified comprise quinones and hydroquinones, organic acids such as citric, ascorbic, tartaric and amino acids and their esters and salts, phenolic antioxidants such as alkylated hydroxy anisoles, gallates such as propyl gallate, and tocopherols.