在自制氧化装置中氧化时间对豆油氧化指标的影响

目的]为了探讨可重复地快速氧化豆油的方法及其氧化程度评价指标体系。方法]以毛豆油为原料,在自制氧化装置和氧化条件下,分别在0、7、14、16、18 d测定酸价（AV）、过氧化值（POV）、碘价（IV）和硫代巴比妥酸反应物（TBARS）等指标,同时测定各时间点油脂的脂肪酸组成。结果]试验条件下,在自制氧化装置中,将氧化温度设定为80℃,豆油POV和TBARS变化大,可以作为快速氧化的指标,当豆油氧化至18 d时,其氧化速度变慢;豆油的AV、IV和TBARS与氧化时长呈2次曲线变化规律,POV与氧化时长呈指数变化规律。以0 d作为对照,氧化至18 d时,AV、POV、TBARS显著升高（P〈0.05）,分别为0 d的1.7、29.0、19.0倍,IV显著降低（P〈0.05）,为0 d的0.91倍;不饱和脂肪酸（UFA）的百分比从84.0%显著降低至82.2%（P〈0.05）。POV、TBARS和SFA、UFA在16和18 d无显著差异（P〉0.05）。结论]确定了自制氧化装置下不同时间豆油氧化指标的变化情况,为建立鱼类肝胰脏损伤试验模型提供了参考。

Variation of the Oxidation Index of Soybean Oil in Home-made Oxidation Device at Different Time

Objective]The research aimed to discuss a new method for the rapid and repeatable oxidation of soybean oil and an evaluation index system for its oxidation degree.Method] In home-made oxidation device and under oxidation conditions,the acid value(AV),peroxide value(POV),iodine value(IV),thiobarbituric acid reactive substances(TBARS) and fat acid of the unrefined soybean oil were determined at 0,7,14,16 and 18 d repectively.Result] under 80 ℃ in the home-made device,the POV and TBARS of the soybean oil changed significantly,therefore,they could act as an indicator of rapid oxidation,the oxidation rate slowed down after 18 days;the AV,IV and TBARS of the soybean oil and the oxidation duration showed a quadratic variation,while its POV and oxidation duration showed a exponential variation.Compare with 0 d,AV,POV and TBARS significantly increased respectively by 1.7,29.0 and 19.0 times(P<0.05),but IV significantly decreased by 0.91 times(P<0.05);UFA significantly decreased from 84.0% to 82.2%(P<0.05).There were no significant difference of POV,TBARS,SFA and UFA betewen 16 d and 18 d of oxidation(P>0.05).Conclusion] The research determined the variation of the oxidation index in the home-made device at different time and provided references for the test model of the hepatopancreas damage of fishes.