Antioxidant properties of tert-butylhydroquinone and propyl gallate in frozen minced sprats

Abstract

Relative effects of the combination of tert-butylhydroquinone (TBHQ) and propyl gallate (PG) with or without a sequestering agent (EDTA or citric acid, C A ) on rancidity development in minced sprats stored at -15 C were determined by following the changes in peroxide values, thiobarbituric acid values, sensory scores, and fatty acid composition of lipid extracts. The combination of 0.02% TBHQ and 0.02% PG was most effective in reducing the rate of oxidative rancidity development in frozen sprats. It allowed an extended induction period of at least 250 days. Lowering the concentration of the additives from 0.02% to 0.01% significantly reduced their antioxidant effectiveness giving rise to larger losses of polyunsaturated fatty acids. Addition of either EDTA or CA to the mixture of 0.02% TBHQ and 0.02% PG did not prevent significant losses of 20:5 and 22:6 fatty acids.