玉米醇溶蛋白与黄色素提取工艺优化及黄色素稳定性研究

Optimization of Extraction of Zein and Yellow Pigment from Corn and Stability of the Yellow Pigment

以生产玉米淀粉的副产物——玉米蛋白粉为原料,筛选有机溶剂浸提玉米醇溶蛋白和黄色素,采用微量凯氏定氮法测定玉米蛋白含量,分光光度法测定玉米黄色素含量。试验结果表明,乙醇体积分数为90%,固液比为1∶15,萃取温度为50℃,萃取时间5 h,提取效果最好;蛋白提取率为89.6%,提取物纯度为84.3%。玉米黄色素提取物中色素的质量分数为0.189%。玉米黄色素随着柠檬酸的质量浓度变化稳定性变化不大;光照和高温对色素的影响很大,所以应该低温暗处保存色素。玉米黄色素对金属离子Fe3+不稳定,耐氧化性能较好。

Zein and yellow pigment are obtained from by- products of corn starch manufacturing by organic solvent extraction.Micro Kjeldahl determination of nitrogen and spectrophotography are applied to measure the content of zein and yellow pigment,respectively. The results show that optimal extraction parameters are as follows：ethanol concentration 90%,solid to liquid ratio 1：15,extraction temperature 50 ℃,and extraction time 5 h. Under these conditions,the extraction yield and purity of zein a re respectively 89.6% and 84.3%, and the yellow pigment yield is 0.189%. The yellow pigment has better stability in the presence of citric acid and oxidation,but sunlight,high temperature and ferric ion are not.