紫背天葵色素的稳定性及其提取工艺优化

以提高紫背天葵色素提取率为目的，分别以甲醇、乙醇、甲醇与乙醇体积分数各为50%的混合溶剂及蒸馏水作为提取剂进行提取对比试验，分析了紫背天葵色素提取液的稳定性。采用均匀设计，探讨了乙醇浓度、提取温度和提取时间对紫背天葵色素提取率的影响。结果表明：紫背天葵色素溶于甲醇、乙醇、甲醇与乙醇混合溶剂及蒸馏水中，乙醇提取剂对紫背天葵色素的溶解度最大，吸光值最高，提取效果最好；紫背天葵色素提取液随pH的变化而变化，pH≤4.1条件下基本保持鲜艳的紫红色，pH>4.1时色素消退；紫背天葵色素提取液不宜采用含铁锌离子的容器盛装，应置低温或室温避光环境中贮放，加热或高温时易氧化褪色。此外，还对紫背天葵色素乙醇提取的工艺参数进行了优化

The Stability of Extract from Begonia finbristipula Hance's Pignent and Optimization of its Processing parameters

In order to improve the extraction rate of fimbristipula Hance’s pigment, the beaker was used to extract the experiment for processing fimbristipula Hance’s pigment, in which methyl alcohol , alcohol, a mixture of 50% methyl alcohol with 50% alcohol and distilled water were used as extracting media to replace pigment from Begonia fimbristipula Hance. The stability of extract of fimbristipula Hance’s pigment was analyzed. An uniform design was carried out to study different influence factors. The effect of alcohol concentration, extraction temperature and extraction time on the extraction process of fimbristipula Hance’s pigment was analyzed. The result showed that fimbristipula Hance’s pigment can dissolve in methyl alcohol, alcohol, mixture of methyl alcohol with alcohol, and distilled water. Dissolvability and quality with alcohol as medium was better than that with methyl alcohol, the mixture of methyl alcohol with alcohol, and distilled water. The extract of fimbristipula Hance’s pigment changes as pH varies, and under pH≤4.1, the extract almost remained bright-purple, while pH ＞4.1, its color gradually faded. As a result. The Begonia fimbristipula Hance’s pigment can only be used as coloring matter for acid food and can not be packaged in a container which contains Zn2 and/or Fe3, and should be preserved in low temperature or normal temperature but avoiding the sunshine for heating or high temperature will easily cause oxidation and fading. A regression analysis of fimbristipula Hance’s pigment with alcohol as medium was carried out and a mathematical model was obtained.