Effect of α-, β-, γ-, and δ-Tocotrienol on the Oxidative Stability of Lard

Despite the structural similarity of tocopherols, the antioxidative activities of tocotrienol homologues have not been studied often. In this study, the antioxidant activities of alpha-, beta-, gamma-, and delta-tocotrienols at various concentrations from 100 to 1,000 ppm in lard were evaluated. Headspace oxygen content of the lard without tocotrienol decreased from 21.1 to 10.7 % and the peroxide value increased from 0.4 to 33.4 mequiv/kg after 7 days of storage at 55 A degrees C in the dark. alpha-Tocotrienol at 100 ppm and beta-tocotrienol at 100 and 200 ppm effectively improved the oxidative stability of lard; however, the antioxidative activities of alpha- and beta-tocotrienol reduced as the concentration increased to 1,000 ppm. The gamma- and delta-tocotrienols improved the oxidation stability of lard and the effectiveness was essentially same at all concentrations (p > 0.05). The antioxidative activities of tocotrienols in the autoxidation of lard increased in the order of alpha-, beta-, gamma-, and delta-tocotrienols. The activities of tocotrienols in lard were different depending on the type of homologues and concentrations.