College of Food Science and Technology, Henan Agricultural University, Zhengzhou 450000, Henan Province, PR China; Lipid Technology and Engineering, College of Food Science and Engineering, Henan University of Technology, Lianhua Road 100, Zhengzhou 450001, Henan Province, PR China.
Lipid Technology and Engineering, College of Food Science and Engineering, Henan University of Technology, Lianhua Road 100, Zhengzhou 450001, Henan Province, PR China.
Food Chem. 2023 Jun 30;412:135512. doi: 10.1016/j.foodchem.2023.135512. Epub 2023 Jan 18.
Phytosterols have health benefits; however, they are partially removed during the bleaching of corn oil. We evaluated the chemical conversion of free phytosterols (FPs) during bleaching. FP degradation accelerated with increased time and temperature, following a first-order kinetic model. In the n-heptane system, air and activated clay promoted the chemical conversion of the FPs. Sterenes formation was analysed under different conditions using a zero-order kinetic model. The apparent activation energies revealed sterene formation decreasing in the following order: campesta-3,5-diene ≈ stigmasta-3,5,22-triene > stigmasta-3,5-diene. Isomers of the above were not detected, indicating that these sterenes were the only primary products of FPs. The desorption test indicated that the FP loss from corn oil was not only due to FPs being adsorbed the activated clay, but also FPs adsorbed at acidic activated sites being degraded. This study presents a vital scientific foundation for retaining FPs to develop healthier and more nutritious oils.
植物甾醇对健康有益，但在玉米油的精炼过程中会被部分去除。我们评估了在精炼过程中游离植物甾醇（FPs）的化学转化。FP 的降解速度随时间和温度的增加而加速，符合一级动力学模型。在正庚烷体系中，空气和活性白土促进了 FPs 的化学转化。使用零级动力学模型分析了不同条件下甾醇的形成。表观活化能表明甾醇的形成顺序依次为：菜油甾-3,5-二烯≈谷甾-3,5,22-三烯＞谷甾-3,5-二烯。未检测到上述异构体，表明这些甾醇是 FPs 的唯一初级产物。解吸试验表明，玉米油中 FP 的损失不仅归因于 FPs 被活性白土吸附，还归因于被酸性活性位吸附的 FP 被降解。本研究为保留 FPs 以开发更健康、更有营养的油提供了重要的科学基础。
