Erythorbic acid Erythorbic acid Erythorbic acid (isoascorbic acid, -araboascorbic acid) is a stereoisomer of ascorbic acid (vitamin C). It is synthesized by a reaction between methyl 2-keto-D-gluconate and sodium methoxide. It can also be synthesized from sucrose or by strains of Penicillium that have been selected for this feature. It is denoted by E number E315, and is widely used as an antioxidant in processed foods. Clinical trials have been conducted to investigate aspects of the nutritional value of erythorbic acid. One such trial investigated the effects of erythorbic acid on vitamin C metabolism in young women; no effect on vitamin C
Chemistry of ascorbic acid the presence of free metal ions can not only promote but also initiate free radical reactions, thus making it a potentially dangerous pro-oxidative compound in certain metabolic contexts. Ascorbic acid and its sodium, potassium, and calcium salts are commonly used as antioxidant food additives. These compounds are water-soluble and, thus, cannot protect fats from oxidation: For this purpose, the fat-soluble esters of ascorbic acid with long-chain fatty acids (ascorbyl palmitate or ascorbyl stearate) can be used as food antioxidants. It creates volatile compounds when mixed with glucose and amino acids in 90 °C. It is a cofactor in tyrosine oxidation.