Role of Xanthine Oxidase in the Development of Spontaneously Oxidized Flavor in Milk

Abstract

Results of the study indicated that (1) the occurrence of a spontaneously oxidized flavor in milk was dependent upon a high level of xanthine oxidase activity, (2) a single enzyme (xanthine oxidase) was involved, and (3) inhibitors of xanthine oxidase were effective in preventing flavor development. Milks possessing a xanthine oxidase activity ranging between 120-140 units were consistent in the production of oxidized flavor. Peroxidase and catalase were also considered but no correlation to oxidized flavor was observed. Varying levels of hypoxanthine, folic acid, p-chloromercuribenzoate and 2-amino-4-hydroxy-6 formyl pteridine were used in the enzyme inhibition studies. A brief discussion of the peroxidatic action of xanthine oxidase was included. 8 pages -4 tables.