紫甘薯渣紫色素的微波提取及精制工艺研究

Study on the microwave-assisted extraction and purification technology of purple pigment from Ipomoes batatas L. pomace

以新鲜紫甘薯渣为原料,采用微波萃取法对其紫色素的提取工艺进行了研究。分析了提取溶剂、料液比、提取温度、提取时间及微波功率等因素对紫甘薯渣紫色素提取效果的影响,在单因素实验基础上利用L9（34）正交实验得到紫甘薯渣紫色素的最佳提取工艺为：提取溶剂pH2盐酸水溶液,料液比1∶5（g/mL）,提取温度70℃,提取时间5min,微波功率600W。采用树脂法对色素进行精制,在供试的14种树脂中,大孔树脂AB-8的精制效果最好;通过静态吸附、解吸实验以及动态吸附实验,确定AB-8大孔吸附树脂精制紫甘薯渣紫色素的工艺条件为：紫甘薯渣紫色素吸光度0.5-0.7、吸附时间1h、色素pH2-3、温度30℃左右、上样流速1mL/min,洗脱液95%乙醇,经上述条件精制紫甘薯渣紫色素色价（524nm）为41.3。

Using fresh Ipomoes batatas L. pomace as material,the technology of microwave-assisted extraction of purple pigment（PP） was studied. The effects of main factors such as extraction solvents,ratio of solid to liquid,temperature and time of microwave extraction,microwave power were investigated. On the basis of single factor test,the optimized extraction conditions of purple pigments from I. batatas L. pomace obtained with an orthogonal design Lg（34） were solid/liquid ratio,extraction temperature,time and microwave power as l：5（g/mL）,70℃,5min and 600W, respectively. The PP were then purified by resin and the resin AB-8 showed the best adsorption and desorption effect among the tested 14 kinds of resins. Its optimized purification conditions obtained by static adsorption,desorption and dynamic adsorption experiments were the absorbance, adsorption time,temperature,pH of PP,feeding flow rate,eluent as 0.5-0.7, lh,about 30℃ ,2-3, l mL/min,and 95% ethanol,respectively. Under this condition,the color scale E（524nm） of purificatory PP was 41.3.