蝶豆花天然色素的提取分离及光热稳定性的实验研究

Optimization of extraction,separation of natural pigment from butterfly pea flower and its photothermal stability

以蝶豆花为原料,柠檬酸水溶液为提取剂,通过溶剂提取法进行提取,利用柱层析法进行分离纯化,并对色素的光热稳定性进行了研究。采用单因素实验的方法考察提取温度、提取时间、料液比对提取效果的影响,最终确定的提取工艺为:提取温度为55℃、提取时间为2.5 h、料液比为1∶30;在单因素实验的基础上,响应面法优化的提取条件为:提取时间为2.5 h、提取温度为52℃、料液比为1∶35。同时还采用单因素试验考察径高比、乙醇浓度及洗脱速率对柱层析分离效果的影响,最佳的分离效果为径高比1∶4.5、乙醇浓度为75%、洗脱效率为3.5 mL/min,在此分离下,可使色素的色价由58.29纯化成186.51,大大地提高了蝶豆花色素的色价。研究表明蝶豆花色素具有很好的热稳定性,光照对色素的影响很大,需避光处理,为蝶豆花色素进一步反应合成和产品开发提供了可能。

The butterfly pea flower pigment was extracted by citric acid and then separated and purified by column chromatography.The photothermal stability of the pigment was studied.The influence of extraction temperature,extraction time and material-liquid ratio on the extraction was investigated by single factor test.The final extraction process conditions were as follows:extraction temperature 55℃,extraction time 2.5 h,and material-liquid ratio 1∶30.On the basis of single-factor experiments,the extraction conditions optimized by response surface method were as follows:extraction time 2.5 h,extraction temperature 52℃,and material-liquid ratio 1∶35.At the same time,a single factor test was used to investigate the influence of diameter to height ratio,ethanol concentration and elution rate on the column chromatography separation.The best separation conditions were as follows:the ratio of diameter to height 1∶4.5,the ethanol concentration 75%,and elution rate 3.5 mL/min.Under the above conditions,the color could be purified from 58.29 to 186.51,which greatly improved the color value of the pigment.This study showed that butterfly pea anthocyanins had good thermal stability,and the light has a great impact on the pigment,so it needs to be protected from light.The results provide references for synthesis and development of butterfly pea anthocyanins in the future.