National Engineering Laboratory of Intelligent Food Technology and Equipment, Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Key Laboratory for Agro-Products Nutritional Evaluation of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agro-Food Processing, Ningbo Research Institute, Fuli Institute of Food Science, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.
National Engineering Laboratory of Intelligent Food Technology and Equipment, Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Key Laboratory for Agro-Products Nutritional Evaluation of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agro-Food Processing, Ningbo Research Institute, Fuli Institute of Food Science, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.
Food Chem. 2019 Aug 1;288:162-169. doi: 10.1016/j.foodchem.2019.02.105. Epub 2019 Mar 2.
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 > 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. 7β-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 7α-hydroxy, 5β,6β-epoxy, 7-keto, 5α,6α-epoxy and 6β-hydroxy. And the oxidation at C7 on the Ring B of steroid nucleus was the most important pathway of phytosterols photooxidation.
在这项工作中，我们研究了油脂基质中植物甾醇在光氧化下的稳定性（不同光照强度、是否存在光敏剂和不饱和脂质）。结果表明，植物甾醇的光氧化符合一级动力学模型（R > 0.96）。当光照强度较高时，速率常数增加，植物甾醇氧化速度加快。光敏剂也可以加速这一过程，而不饱和基质则抑制了氧化产物的形成。在所有模型基质样品中都检测到了植物甾醇氧化产物（POPs）。在整个光照处理过程中，7β-羟基是大多数情况下的主要氧化产物，约占总植物甾醇氧化物的三分之一，其次是 7α-羟基、5β,6β-环氧、7-酮、5α,6α-环氧和 6β-羟基。甾核环 B 上 C7 位的氧化是植物甾醇光氧化的最重要途径。
