Photooxidation of phytosterols in oil matrix: Effects of the light, photosensitizers and unsaturation degree of the lipids
Photooxidation of phytosterols in oil matrix: Effects of the light, photosensitizers and unsaturation degree of the lipids
复制标题
油基质中植物甾醇的光氧化：光、光敏剂和脂质不饱和度的影响
DOI：
10.1016/j.foodchem.2019.02.105
复制
发表时间：
2019-08-01
期刊：
影响因子：
8.8
通讯作者：
Lu, Baiyi
中科院分区：
文献类型：
--
作者：
Zhao, Yajing;Yang, Bowen;Lu, Baiyi
本文研究了光氧化条件下（不同光强、光敏剂和不饱和脂质的存在与否）油脂基质中植物甾醇的稳定性。结果表明，植物甾醇的光氧化反应符合一级动力学模型（R-2 > 0.96）。光照强度越大，反应速率常数越大，植物甾醇氧化速度越快。光敏剂也可以加速这一过程，而不饱和基质则抑制氧化产物的形成。在所有模型基质样品中检测到植物甾醇氧化产物（POPs）。在整个光处理过程中，7-羟基是主要的氧化产物，约占植物甾醇氧化物总量的1 / 3，其次是7-羟基、5 -、6 -环氧、7-酮、5 -、6 -环氧和6 -羟基。甾体核B环C7上的氧化是植物甾醇光氧化最重要的途径。
In this work we studied the stability of phytosterols in oil matrix under photooxidation (with different light intensity, existence/absence of photosensitizers and unsaturated lipids). Results revealed that the photooxidation of phytosterols fit a first order kinetic model (R-2 > 0.96). When the intensity of light was higher, the rate constants increased and phytosterols oxidized faster. The progress could be also accelerated by photosensitizers, whereas the unsaturated matrix inhibited the formation of oxidation products. Phytosterols oxidation products (POPs) were detected in all model matrix samples. 7 beta-hydroxy was the main oxidation products in most cases during the whole treatment under light, which represented about one third of the total phytosterol oxides, followed by 7 alpha-hydroxy, 5 beta, 6 beta-epoxy, 7-keto, 5 alpha, 6 alpha-epoxy and 6 beta-hydroxy. And the oxidation at C7 on the Ring B of steroid nucleus was the most important pathway of phytosterols photooxidation.