杜仲籽精炼油的氧化稳定性及货架期预测

本文以杜仲籽毛油为原料，经过精炼后以过氧化值、酸价和脂肪酸含量为评判指标，采用Schaal烘箱法探究了5种抗氧化剂在不同浓度和温度下对杜仲籽精炼油氧化稳定性的影响，建立了杜仲籽精炼油货架期模型，预测其货架期。结果表明，添加丁基羟基茴香醚（butyl hydroxyanisole，BHA）、叔丁基对苯二酚（tert-butyl hydroquinone，TBHQ）、维生素E（vitamin E，V_E）、鼠尾草酸（carnosic acid，CA）和L-抗坏血酸棕榈酸酯（L-ascorbyl palmitate，L-AP）的抗氧化效果从大到小依次为TBHQ>CA>L-AP>BHA>V_E，CA、TBHQ、V_E、BHA、L-AP的最佳添加量分别为0.05%、0.02%、0.01%、0.02%、0.02%；随着储藏温度的升高和储藏时间的延长，过氧化值和酸价升高，氧化速度加快，饱和脂肪酸和单不饱和脂肪酸含量增加，不饱和脂肪酸含量减少；杜仲籽精炼油的氧化符合一级氧化动力学反应，通过构建的杜仲籽精炼油货架期模型，预测出在25、40、50和60 ℃的温度下，杜仲籽精炼油的货架期分别为10.70、8.76、7.74和6.89 d，添加抗氧化剂能延缓不饱和脂肪酸的氧化，其中TBHQ的抗氧化效果最好，添加0.02% TBHQ的杜仲籽精炼油的货架期可以延长至41.41、19.71、12.48和8.13 d，说明添加抗氧化剂可以有效延长杜仲籽精炼油的货架期。

Oxidation Stability and Shelf Life Prediction of Refined Eucommia ulmoides Seed Oil

Taking crude Eucommia ulmoides seed oil as raw material, after refining, the effects of antioxidants and temperature on the oxidation stability of refined Eucommia ulmoides seed oil were studied by Schaal oven test according to peroxide value, acid value and fatty acid content. The shelf life model of refined Eucommia ulmoides seed oil was established and the shelf life was estimated. The results showed that the antioxidant effects of butyl hydroxyanisole (BHA), tert-butyl hydroquinone (TBHQ), vitamin E (V_E), carnosic acid (CA) and L-ascorbyl palmitate (L-AP) were in the order of TBHQ>CA>L-AP>BHA>V_E, and the optimum addition of CA, TBHQ, V_E, BHA and L-AP were 0.05%, 0.02%, 0.01%, 0.02% and 0.02%, respectively. With the increasing of storage temperature and time, the peroxide value, acid value and the oxidation rate increased, the content of saturated fatty acid and monounsaturated fatty acid increased, and the content of unsaturated fatty acid decreased; the oxidation of refined Eucommia ulmoides seed oil followed the first-order oxidation kinetic reaction, and the shelf life was predicted to be 10.70, 8.76, 7.74 and 6.89 d at 25, 40, 50 and 60 ℃ respectively. Adding antioxidants could delay the oxidation of unsaturated fatty acids, and the antioxidant effect of TBHQ was the best, the shelf life of refined Eucommia ulmoides seed oil with 0.02% TBHQ could be extended to 41.41, 19.71, 12.48 and 8.13 d. It was suggested that, the shelf life of refined Eucommia ulmoides seed oil could be effectively prolonged by adding antioxidants.