正交试验法对黑米黑色素的微波提取工艺研究

Study on Melanin Extraction from Black Rice by Microwave and Orthogonal Test

采用正交试验法,利用微波萃取技术,对黑米中黑色素的最佳提取工艺进行了深入研究。以黑米黑色素的提取率作为考查指标,用分光光度法进行测定,利用单因素试验分别考察了提取剂乙醇浓度、料液比、微波功率、微波提取时间在不同水平下对黑色素提取率的影响程度,通过正交试验对影响黑色素提取率的因素进行了优化研究。试验结果表明:乙醇浓度是影响黑米黑色素提取的最关键因子。优化得到黑色素的最佳提取工艺参数为:浸提剂乙醇浓度为80%、料液比1∶20、微波作用功率为480W、微波作用时间为120s。在此试验条件下,黑米黑色素的提取率达到3.2%,为先前文献报导的2.2倍。试验所得黑色素色泽纯正,且带有黑米的清香,该工艺有良好的应用前景。

The optimal conditions for microwave-assisted extraction of melanin from black rice were investigated by the orthogonal experimental design.The content of melanin as research index in the extractant was tested by spectrophotometry.Single factor analysis of four factors such as extraction solvent（ethanol） concentration,soild-liquid ratio,microwave extraction power,extraction time in several levels was conducted to investigate their influence on the extraction yield.Then,the influencing factors of melanin extraction were optimized by orthogonal test.The results suggested that the ethanol concentration should be the statistically significant factor.The optimal parameters of the extraction process were as follows：ethanol concentration （80%）,solid-liquid ratio（1：20）,microwave output power（480W） and microwave irradiation time（120s）.Under the optimal experimental condition the extraction yield of melanin from black rice reached 3.2%,which was increased by a factor of 1.2 compared with the former data.The melanin from black rice is coloury with faint scent.The extraction technology of melanin has an extensive application prospect.