Abstract
To evaluate the loss of biologically active cobalamin in milk during light-induced riboflavin degradation, various milk samples were exposed to fluorescent light (3, 500 lx) for 24 h at 4°C. Total cobalamin was extracted and assayed by the chemiluminescent method with the hog intrinsic factor, a mammalian cobalamin-binding protein. The cobalamin concentration was decreased by between 1% and 27%, depending on the type of milk tested. This loss of cobalamin may be indirectly due to the free radicals formed by light-induced riboflavin.
