δ-生育酚在精炼油脂中的抗氧化效果及其热损耗

ANTIOXIDANT ACTIVITY AND THERMAL LOSS OF δ-TOCOPHEROL IN REFINED OILS AND FATS

以精炼动植物油脂(大豆油、棕榈油、茶油和猪油)为原料,以δ-生育酚为研究对象,采用Rancimat法(110℃)和烘箱法(180℃)研究了加热条件下,δ-生育酚在油脂中的抗氧化活性、损耗情况及其对油脂品质的影响。Rancimat试验结果表明:添加δ-生育酚(500、1 000 mg/kg)能有效延长棕榈油、茶油和猪油的氧化诱导期,且油脂氧化诱导期与δ-生育酚添加量(500~1 000 mg/kg)呈正相关,而对于大豆油,添加δ-生育酚对其氧化诱导时间无显著影响。110℃下,在棕榈油中,1 000 mg/kg的δ-生育酚抗氧化效果优于200 mg/kg的BHT,但与200 mg/kg的TBHQ相比较弱;在猪油中,1 000 mg/kg的δ-生育酚抗氧化效果显著优于200 mg/kg的BHT和TBHQ(P<0.05)。烘箱试验结果表明:δ-生育酚在油脂中的损耗率随加热时间延长而不断增大,增大其添加量能有效抑制其损耗率的增大;在大豆油、茶油和猪油中,δ-生育酚对油脂茴香胺值的增大具有显著的抑制作用(P<0.05),但在棕榈油中,500、1 000 mg/kgδ-生育酚对其茴香胺值增大均具有促进作用。

In this study,the antioxidant activity,thermal loss ofδ-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 thatδ-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 ofδ-tocopherol(500~1 000 mg/kg),while it had no significantly influence on the IP of soybean oil.Under 110℃,the antioxidant activity ofδ-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 ofδ-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 ofδ-tocopherol in oils increased with the heating period prolonging,and the loss rates were negatively related to the addition amout ofδ-tocopherol.δ-tocopherol could effectively inhibit the increasing of the anisidine value(p-AnV)of soybean oil,tea seed oil,and lard under 180℃,butδ-tocopherol(500,and 1000 mg/kg)showed significantly promoting effect on the increasing of the p-AnV in palm oil.