The destruction of vitamin a by rancid cod liver oil

Vitamin A Destruction in Fish Liver Oils

“…Lease et al (10) observed that, if oxidized fat and vitamin A were fed separately but at the same time, the combination resulted in lower storage of vitamin A in the liver, and they suggested that the preformed peroxides in the fat destroy the vitamin A between the time of feeding and storage in the liver. Whipple (21) reported a drop in vitamin A potency of cod liver oils as the peroxide value increased, and Lowen et al (11) found that vitamin A in halibut and salmon oils was rapidly destroyed after the termination of the induction RELATION TO PEROXIDE FORMATION period as judged by the peroxide value. While our work was in progress, Smith (19) reported that vitamin A dissolved in rancid fats containing peroxides was destroyed in the absence of air at a rate approximately proportional to the peroxide concentration.…”

Free Fatty Acids and Rancidity in Relation to Animal By-Product Protein Concentrates

“…Powick (1925) first reported the destruction of vitamin A by intensely rancid lard. Mattill (1927) found that the oxidative changes that accompany rancidity in fats tended to destroy vitamins A and E. Whipple (1936) noted the destruction of vitamin A in cod liver oil as rancidity developed. Smith (1939) noted that the destruction of vitamin A in oil solution was proportional to the peroxide value of the oil.…”

Effect of treated fats on vitamin A potency

“…Lease (57) discovered that hydrogenation of a fat, to the extent that it prevented rancidity, tended to stabilize and protect the vitamin A activity of the fat. Data published by a number of investigators (1,3,4,5,6,7,8,9,50,54) have shown that oxidized fats destroyed vitamin A activity. Oxi dized fats possessed this property regardless of the manner in which the oxidation was achieved, whether brought about by subjecting the fat to aeration, storage, heat, ozonization, irradiation, or any combination of these processes as long as oxygen was present (48).…”