Volatilization and Decomposition of Antioxidants by Heating

Abstract

BHA and BHT were heated in liquid paraffin and residual amounts of them were determined by UV spectroscopy. Both antioxidants decreased rapidly with increasing heating temperature. Decreasing rate of BHA was about two times that of BHT. Addition of flour dough to liquid paraffin accelerated the decomposition of antioxidants. The degradation products separated from BHA which was heated under an oxygen stream at 180°C for one hour were analyzed by GLC and GC-MS spectroscopy. Over 10 volatile compounds and 15 nonvolatile compounds were detected, however, the main product among them was a dimer type of BHA. The degradation processes of BHA were discussed from the viewpoint of the free radical reaction. Heating of salad oil containing BHA at 120°C resulted in maximum yield of the dimer.