L-抗坏血酸棕榈酸酯对亚麻酸甘油三酯热致异构反式产物动力学的影响

Effects of L-ascorbyl Palmitate on the Kinetics of Thermally Induced Trans Products of Trilinolenin

研究0.02%L-抗坏血酸棕榈酸酯(L-AP)对亚麻酸甘油三酯在200~240℃加热2~48 h反式产物的动力学的影响。采用高极性离子液毛细管柱分析亚麻酸甘油三酯高温加热,结果有3种单反式(C18:3-9t,12c,15c、C18:3-9c,12t,15c和C18:3-9c,12c,15t)和2种反式(C18:3-9t,12c,15t和C18:3-9t,12t,15c)异构体生成,该反应为零级反应。L-AP虽然不改变单反式和双反式异构体的形成反应级数,但是能降低单反式和双反式异构体的形成速率,其主要作用是抑制单反式异构体的形成,主要作用位点是先阻止亚麻酸链上15位氢发生异构,然后依次是9位和12位氢发生异构。此外,建立L-AP存在条件下,亚麻酸甘油三酯热致异构反式产物浓度与加热温度和时间的预测模型。

Effects of 0.02% L-ascorbyl palmitate(L-AP) on the kinetics of trans products of trilinolenin heated at 200-240 ℃ for 2-48 h were studied. Three kinds of single trans isomers(C18:3-9 t,12 c,15 c, C18:3-9 c,12 t,15 c and C18:3-9 c,12 c,15 t) and two kinds of double trans isomers(C18:3-9 t,12 c,15 t and C18:3-9 t,12 t,15 c) were detected in heated trilinolenin analyzed by highly polar ionic liquid capillary columns. The formations of these trans isomers were zero-order reactions, and the reaction orders of these isomers were not changed by the addition of L-AP. L-AP could inhibit the formation rates of single and double trans isomers. The main role of L-AP was to inhibit the formation of single trans isomers, and the inhibit site was the isomerization of 15 hydrogen in linoleic acid chain, followed by 9 hydrogen12 hydrogen. In addition, the forecasting model of thermally induced trans products concentration of trilinolenin, heating temperature and time were established in the presence of L-AP.