Abstract:
In this study,the antioxidant activity,thermal loss of
δ-tocopherol and its effect on the quality of soybean oil,palm oil,tea seed oil,and lard were investigated by using Rancimat method (110℃) and oven method (180℃).Results showed that
δ-tocopherol could significantly prolong the oxidation induction period (IP) of tea seed oil,palm oil,and lard,and the IP value were positively related to the addition amount of
δ-tocopherol (500~1 000 mg/kg),while it had no significantly influence on the IP of soybean oil.Under 110℃,the antioxidant activity of
δ-tocopherol (1 000 mg/kg) was stronger than BHT (200 mg/kg),but was less potent than TBHQ (200 mg/kg) in palm oil;the antioxidant activity of
δ-tocopherol (1 000 mg/kg) was significantly stonger both than BHT (200 mg/kg) and TBHQ (200 mg/kg)(
P<0.05) in lard.The results of oven test indicated that the thermal loss rate of
δ-tocopherol in oils increased with the heating period prolonging,and the loss rates were negatively related to the addition amout of
δ-tocopherol.
δ-tocopherol could effectively inhibit the increasing of the anisidine value (
p-AnV) of soybean oil,tea seed oil,and lard under 180℃,but
δ-tocopherol (500,and 1000 mg/kg) showed significantly promoting effect on the increasing of the p-AnV in palm oil.