Comparison of the Rates of Vitamin Degradation when Mixed with Metal Sulphates or Metal Amino Acid Chelates

Mixes containing retinol, cholecalciferol, tocopherol, menadione, thiamin, riboflavin, pyridoxine, cyanocobalamin, ascorbic acid, nicotinamide, pantothenic acid, folic acid, and biotin were blended with either metal sulphates or metal amino acid chelates of Cu, Zn, Fe, Mn, and Co. Half of the mixes were stored at 37°C and the other half at 20°C. Vitamin potencies were determined at 0, 90, and 180 days. The percentages of losses of retinol, menadione, pyridoxine, and ascorbic acid were significantly less when these vitamins were stored with metal amino acid chelates compared to storage with metal sulphates at either temperature. There was significant degradation of pyridoxine and riboflavin at 37°C and of ascorbic acid, retinol, and menadione at 20°C in the presence of the metal sulphates, but not in the presence of the amino acid chelates. It was concluded that in stored foods containing vitamins and minerals, there would be significantly less degradation of the vitamins prone to oxidation if the sources of the added minerals were amino acid chelates.