乙酸酐/乙酸法制备油溶性胭脂虫红色素

摘要

胭脂虫红色素是水溶性极好的天然色素,改善其油溶性后可拓展该色素在油溶性食品、化妆品、药品、化工等行业的应用.本文以乙酸酐/乙酸为反应体系,对其有效染色成分胭脂红酸分子进行化学修饰后制得了油溶性胭脂虫红色素衍生物.通过单因素及响应曲面优化实验确定了制备油溶性胭脂虫红色素衍生物的最佳工艺参数为:胭脂虫红色素0.5g; 乙酸酐与乙酸用量均为10mL; 催化剂三乙胺用量为1.0mL; 反应温度70℃; 反应时间为8h; 此条件下油溶性胭脂虫红色素衍生物收率为65.2%.通过紫外可见光谱、红外光谱对所得到的色素产物进行了初步的结构表征,表明胭脂虫红酸分子中增加了酯基和烷基,得到的产物在油样中的溶解度为 2.41(25℃),且稳定性良好,说明胭脂虫红色素的油溶性得到有效的改善,具有开发和应用潜在价值与前景.%Cochineal is one of the most valuable water soluble natural pigments. Improving its oil soluble may contribute to the application on oil soluble food,cosmetics,medicines,etc. Herein, oil-soluble cochineal dye was obtained by molecule esterification of carminic acid with acetic anhydride/acetic acid in this paper. Based on single factor experiments,response surface methodology has been applied to further optimize pretreatment condition. Under the optimal condition,i.e. cochineal dye was 0.5g,acetic anhydride and acetic acid dosage were 10mL,catalyst dosage of triethylamine was 1.0mL,reaction temperature was 70℃,and reaction time was 8h,the yield of cochineal dye derivatives reach up to 65.2%. The target product showed good solubility in corn oil,good dyeing effect and good stability with 2.41g in oil (25℃). This suggests that cochineal dye derivatives have potential value and promising development prospects.