响应面法优化紫五加色素提取工艺及其稳定性研究

Optimization of pigment extraction from purple Acanthopanax senticosus by response surface methodology and its stability

以紫五加为原料,利用超声波辅助法提取紫五加色素.在单因素实验的基础上,采用响应面分析法优化提取方案.结果表明,紫五加色素最佳提取工艺条件(修正)为:液料比为60∶1,乙醇体积分数为85%,超声功率320W,超声时间94min.此工艺条件下提取的紫五加(烘干枝梢部分)色素吸光度值可达0.756(预测值0.760).各部分色素含量顺序:c(叶)>c(枝梢)>c(茎)>c(根).除叶外,前处理方式(烘干或风干)对紫五加色素提取影响不大.紫五加色素稳定性研究表明:抗氧化剂(异抗坏血酸,C6H8O6)、氧化剂(H2O2)、还原剂(Na2SO3)和蔗糖均明显影响紫五加色素稳定性;金属离子Ca^2+,Na^+和Fe^3+对紫五加色素的影响较小,而Mg^2+,Al^3+,Zn^2+,Cu^2+和Mn^2+影响较大;10℃~90℃温度范围内,溶液pH<7,自然光或紫外光照射,加入NaCl溶液均对紫五加色素无明显影响.

Ultrasonic-assisted extraction of pigment was carried out by using purple Acanthopanax senticosus as the raw material.Based on the single factor experiment,response surface methodology was used to optimize the extraction scheme.The results showed that the optimal extraction conditions(correction) of pigment from purple Acanthopanax senticosus were determined as follows:the ratio of solvent to solid was 60∶1,ethanol volume fraction was 85%,ultrasonic power was 320Wand ultrasonic time was 94min.Under the optimal conditions,the absorbance value of pigment extracted from purple Acanthopanax senticosus can reach 0.756(the predicted value was 0.760).The pigment content in different organs showed that the order from high to low was leaf,shoot,stem and root.In addition to the leaves,the pretreatment method(the oven drying or air drying) has little effect on the extraction of pigment.The study on the stability of pigment indicated that antioxidant(isoascorbic acid,C6H8O6),oxidant(H2O2),reducing agent(Na2SO3)and sucrose all significantly affected the stability of pigment.Ca^2+,Na^+ and Fe3+had little effect on pigment,while Mg^2+,Al^3+,Zn^2+,Cu^2+and Mn^2+ had great influences.In the temperature range of 10℃ to 90℃,the pH of the solution is less than 7,natural light or ultraviolet light irradiation and the addition of NaCl solution has no obvious effect on the pigment.