精制米糠蜡的工艺条件

STUDY ON THE TECHNOLOGICAL CONDITIONS OF REFINED RICE BRAN WAX

以含油较高的毛糠蜡为原料,采用异丙醇溶剂脱除米糠蜡中的甘油酯及脂肪酸;通过单因素试验考察了萃取时间、温度、料液比3因素对脱除甘油酯效果的影响.在单因素基础上进行了基于Box-Behnken设计的响应面法优化分析,以纯度为指标,方差分析结果表明:回归模型较好地反映了米糠蜡纯度与时间、温度、料液比的关系.通过二次回归模型分析得出影响因素主次顺序为料液比>温度>时间.最佳工艺条件为:49 min、58℃、料液比1∶6,在此条件下进行3次平行验证试验,得到精制米糠蜡中丙酮不溶物由49.57%提高至90.09%,得率为86.71%,试验值与预测值吻合良好.得到的米糠蜡在此基础上进行了二次萃取,所得产品纯度达到98.7%,得率为84.35%.

The article extracted glyceride and fatty acids from crude rice bran wax with higher oil content by using isopropyl alcohol,and studied the influences of the extraction time,the temperature and the solid-to-liquid ratio on the glyceride removal effect by single factor experiments.Based on the single factor experiments,we conducted Box-Behnken response surface design,taking purity as the index.The variance analysis results showed that the regression module well reflected the relationship between the purity of the rice bran wax and the time,the temperature and the solid-to-liquid ratio.Through quadratic regression model,we found the important order of the influence factors as follows： solid-to-liquid ratio,temperature and time;and the optimal conditions were as follows： time 49 min,temperature 58 ℃,and solid-to-liquid ratio 1︰6.We conducted three parallel tests under the optimal conditions,and found that the acetone insoluble matters in the refined rice bran wax was improved from 49.57% to 90.09%,and the yield was up to 86.71%;the test value was in good accordance with the predicted value.We also extracted the obtained rice bran wax for the second time to obtain the refined product with the purity of 98.7% and yield of 84.35%.