Studies on the Decomposition of Tocopherol and Oxidation Products of Edible Oils

In the previous papers, the authors reported that the decomposition of tocopherol in oxidative rancid oil increases more than those in non-rancid oil.In this paper, the influence on decomposition of tocopherol by oxidation products of oil was investigated. That is for the effect of free fatty acid and peroxide in oil on the decomposition of tocopherol. For examination the following kinds of lard were prepared, namely, without addition of dl-α-tocopherol; with addition of tocopherol by 0.2%; 0.2% tocopherol plus 0.32.3% fatty acid; 0.250.5mg% iron (some iron salts) added thereto; and 13% benzoyl peroxide added thereto; and they were heated at 180°C for 24hrs.The results obtained were as follows;1. Fatty acid and iron in oils did not promote the decomposition of tocoehhrol.2. The decomposition of tocopherol was apparently promoted by the peroxide of oil and the addition of benzoyl peroxide.