Lipid Technology and Engineering, College of Food Science and Engineering, Henan University of Technology, Zhengzhou, China.
National Engineering Laboratory for Wheat and Corn Further Processing, Henan University of Technology, Zhengzhou, China.
J Sci Food Agric. 2021 May;101(7):2736-2743. doi: 10.1002/jsfa.10900. Epub 2020 Nov 13.
Phytosterols are partly removed during oil refining, and the magnitude of phytosterols loss largely depends on the refining conditions applied and the molecular conformation. The aim of this research was to study the effect of deodorization conditions and molecular unsaturation on the esterification of phytosterols during deodorization of corn oil.
In the chemical model, free fatty acids (FFAs) were the major provider of acyl groups during the formation of phytosteryl fatty acid esters (PEs) under deodorization conditions. Among the main parameters of the deodorization, temperature played a role in the formation of PEs with a time-dependent manner. In comparison, saturated palmitic acid had a higher capability of esterifying free phytosterols (FPs) to PEs than unsaturated oleic acid and linoleic acid. Moreover, the influence of FFA unsaturation on the degradation of FPs depended on temperature. Besides, the formation of stigmasteryl ester had a competitive advantage over that of sitosteryl ester by quantum chemistry simulation.
For laboratory-scale deodorization of corn oil, saturated fatty acids and deodorization process with steam as stripping gas could obviously esterify FPs to PEs. FPs were abundantly enriched in distillate during the deodorization process with nitrogen as stripping gas, whereas FPs and PEs were distilled simultaneously during the deodorization process with steam. © 2020 Society of Chemical Industry.
在精炼油的过程中，植物甾醇会有部分被去除，而甾醇损失的程度在很大程度上取决于所应用的精炼条件和分子构象。本研究的目的是研究玉米油脱臭过程中脱臭条件和分子不饱和度对植物甾醇酯化的影响。
在化学模型中，游离脂肪酸（FFAs）是甾醇脂肪酸酯（PEs）形成过程中酰基的主要来源，在脱臭条件下。在脱臭的主要参数中，温度以时间依赖的方式在 PEs 的形成中起作用。相比之下，饱和棕榈酸比不饱和油酸和亚油酸更能将游离植物甾醇（FPs）酯化形成 PEs。此外，FFA 不饱和度对 FPs 降解的影响取决于温度。此外，通过量子化学模拟，菜油甾醇酯的形成比谷甾醇酯具有竞争优势。
对于玉米油的实验室规模脱臭，饱和脂肪酸和以蒸汽作为汽提气体的脱臭过程可以明显地将 FPs 酯化形成 PEs。在以氮气作为汽提气体的脱臭过程中，FPs 在馏出物中大量富集，而在以蒸汽作为汽提气体的脱臭过程中，FPs 和 PEs 同时被蒸馏出来。 © 2020 化学工业协会。
