State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, People's Republic of China.
Department of Food Science and Engineering, Guangdong Saskatchewan Oilsee Joint Laboratory, Jinan University, Guangdong 510632, People's Republic of China.
Food Chem. 2017 Apr 15;221:1434-1441. doi: 10.1016/j.foodchem.2016.11.008. Epub 2016 Nov 2.
Promotion of water to the thermal oxidation of oleic acid was detected by the combination of EPR, SPME-GC-MS/MS and GC. Spin-trapping technique was used to identify and quantify the radical species formed during thermal oxidation of oleic acid by using DMPO as electron spin trap. The most abundant radical species were identified as DMPO-alkyl radical adducts. EPR intensity plateau of the samples with 5% water content was 140% higher than the samples without water. It implies oleic acid samples with high water content had high level of oxidation rates. The proportion of aldehydes of the samples with 2% water content was the maximum about 59.97%. Among the formed products, (E,E)-2,4-decadienal has genotoxic and cytotoxic effects, whose percentage was nearly twice comparing with that of 5-0% water content. This study demonstrated that higher water content in frying systems would contribute to seriously oxidation and degradation of oleic acids.
通过 EPR、SPME-GC-MS/MS 和 GC 的结合，检测到水对油酸的热氧化促进作用。自旋捕获技术被用来识别和定量在油酸的热氧化过程中形成的自由基，方法是使用 DMPO 作为电子自旋捕获剂。通过 DMPO 捕获的最丰富的自由基种类被鉴定为 DMPO-烷基自由基加合物。水含量为 5%的样品的 EPR 强度平台比不含水的样品高 140%。这意味着含水量高的油酸样品具有更高的氧化速率。水含量为 2%的样品中醛的比例最高，约为 59.97%。在所形成的产物中，（E，E）-2,4-癸二烯醛具有遗传毒性和细胞毒性作用，其百分比几乎是水含量为 5-0%的两倍。本研究表明，在油炸体系中较高的含水量会导致油酸严重氧化和降解。
