米糠油脱酸过程中保留去甲基甾醇的工艺优化

Optimization of Alkali Refining to Produce Rice Bran Oil With High Retain of Des-methyl Phytosterol

研究了脱酸温度、碱液浓度以及超量碱的加入量对高酸价米糠油中去甲基甾醇绝对质量的影响。研究表明:三者对米糠油的精炼率及皂脚吸附去甲基甾醇的损失有不同程度的影响,优化所得最大保留去甲基甾醇在脱酸油中的反应条件为:反应温度55℃,碱液浓度5.99 mol/L,超量碱的加入量为0.2%,该条件下去甲基甾醇相对百分含量的保留率为86.56%,米糠油酸值为0.69 mgKOH/g,精炼率为51.01%,去甲基甾醇绝对质量的保留率为44.02%。经脱酸,去甲基甾醇主要类型不变,菜油甾醇占总的去甲基甾醇中的比例下降,而β-谷甾醇所占比例略微上升。

The influences of deacidification temperature, alkali concentration and the amount of excess alkali on the absolute mass of des - methyl phytosterol these three elements in rice bran oil with high acid value have been studied in the paper. The results showed that all three had varying degrees effects on refining yield and soapstock absorption on the des- methyl phytosterol. The optimization conditions of alkali refining to produce rice bran oil with high retain of des - methyl phytosterol were as follows： deacidification temperature of 55 ℃, alkali concentration of 5.99 mol/L, the amount of excess alkali of 0.2%. On the conditions, the relative percentage retention rate of desmethyl phytosterol was of 86.56%, acid value of 0. 69 mgKOH/g, refining yield of 51.01%, the absolute quality retention rate of desmethyl phytosterol of 44.02%. After deacidification, the forms of desmethyl phytosterol in rice bran oil had no alteration, however, the propor- tion of campesterol in desmethyl phytosterol decreased while the proportion of β -sitosterol increased.