Abstract
The effect of silicon oil (poly dimethyl siloxaneKF-96)) on the thermal decomposition of tocopherols (Toc) in oils or Toc added to fatty acid methyl esters was investigated. Oils (soybean, rapeseed and olive oils) and fatty acid methyl esters (methyl oleate and linoleate) were heated in a glass tube (2.7×20cm)at 180°C, and residual Toc, anisidine and carbonyl values were detefmined. Silicon oil showed preventive effects against the thermal decomposition of Toc and thermal oxidation of oils and fatty acid methyl esters. The ratio of prevention on thermal decomposition of Toc and thermal oxidation of soybean and rapeseed oils or methyl linoleate increased according to the amount of silicon oil added. The preventive effect of silicon oil on the thermal decomposition of Toc was observed much higher in olive oil or methyl oleate than in soybean and rapeseed oils or linoleate. The results suggest that high correlation exists among degree of residual Toc and thermal oxidation of oils.
