脱臭过程中保留米糠油中植物甾醇的工艺优化

Optimization of deodorization process for retention of phytosterols in rice bran oil

采用氮气蒸馏法进行米糠油的脱臭,研究了脱臭温度、脱臭时间以及氮气流速对脱臭米糠油中植物甾醇含量的影响。结果表明,在保证得到高品质米糠油的前提下,最大程度保留脱臭油中植物甾醇的优化工艺条件为:脱臭温度260℃,脱臭时间120 min,氮气流速0.12 m3/h。在最优工艺条件下,植物甾醇保留率(相对于脱色油)为83.38%,米糠油酸值(KOH)为0.25 mg/g,精炼率为93.01%。同时发现,脱臭前后米糠油中植物甾醇的主要组成成分没有变化,均为豆甾醇、菜油甾醇和β-谷甾醇。

The bleached rice bran oil was deodorized by nitrogen distillation,and the effects of deodorization temperature,dedorization time and flow rate of nitrogen on the phytosterol content of rice bran oil were studied. The results showed that ensuring high quality rice bran oil,the deodorization process conditions for maximum retention of phytosterol in deodorized oil were optimized as follows:deodorization temperature 260 ℃,deodorization time 120 min and flow rate of nitrogen 0. 12 m3/h. Under the optimal conditions,the retention rate of phytosterol was 83. 38% (based on bleached oil),refining yield was 93. 01%,and the acid value of deodorized rice bran oil was 0. 25 mgKOH/g. At the same time,it was found that the main components of phytosterol in rice bran oil did not change before and after deodorization,and they were stigmasterol,campesterol and β-sitosterol.