精炼过程中玉米油甾醇含量的变化

Changes of phytosterols content in corn germ oil at different steps of refining

植物甾醇对人体具有十分重要的生理功能,在玉米油中含量较高。通过对不同精炼阶段的玉米油中甾醇含量的分析测定,发现玉米原油至碱炼油阶段甾醇损失37%,至脱色油阶段损失50%,而玉米原油至一级油阶段损失高达68%,说明植物甾醇在油脂精炼过程中有较大损失。通过正交实验对碱炼玉米油在脱色过程中的甾醇损失状况进行了研究,结果表明在脱色过程中对甾醇含量影响的因素依次为:脱色剂用量>脱色温度>脱色时间。因此,为了在精炼过程中保留甾醇,应降低精炼程度,特别是降低碱炼和脱色程度。

Corn germ oil contains rich phytosterols which has a very important physiological functions on human. The contents of phytosterols in corn germ oil at different steps of refining processes were determined. The results showed that the loss of phytosterols reached 37% from crude oil to neutralized oil, 50% from crude oil to bleached oil,and 68% from crude oil to 1st grade oil. The effect of bleaching on the loss of phytosterols was studied by orthogonal experiments. The significance of the main effects of the variables on the phytosterols content decreased in the order：bleaching earth dosage, bleaching tempera- ture, bleaching time. In order to reserve the phytosterols, the degree of refining should be reduced, especially the degree of neutralization and bleaching.