黑米花青素酶法提取工艺优化及颜色稳定性测定

Enzymatic Extraction Process and Color Stability of Anthocyanins in Black Rice

摘要: 利用响应面法对酶法辅助提取黑米花青素工艺进行优化，制备主要单体矢车菊素-3-O-葡萄糖苷(cyanidin-3-O-glucoside, C3G)并研究氨基酸对C3G颜色稳定性的影响。以花青素得率为指标，在单因素试验基础上，结合响应面法，确定最佳提取条件，进而通过AB-8、聚酰胺树脂和半制备液相色谱分离纯化出C3G。采用分光光度法和色差测定，研究4种氨基酸对C3G颜色稳定性的影响。结果表明，酶法提取的最佳工艺条件为：柠檬酸浓度3.5%、酶的种类α-淀粉酶、酶的添加量95 U/mL、温度50℃、时间125 min和液料比14:1 mL/g，在此条件下，花青素的平均得率为1.725‰，纯度为71.24%；4种氨基酸均增加了C3G的颜色稳定性，其中半胱氨酸的辅色作用最为显著。因此，酶法提取花青素是一种切实有效的提取方法，及氨基酸的辅色作用对扩大花青素的应用范围具有重大意义。

Abstract: In this paper, enzymatic extraction process of black rice anthocyanins was optimized by response surface analysis, the main monomer C3G was prepared and the effect of amino acids on color stability of C3G was studied. The extraction conditions were determined by single factor tests in terms of anthocyanin yield. On this basis, the extraction parameters were optimized by response surface analysis, then C3G was separated and purified by AB-8 macroporous, polyamide resin and semi-prepared liquid chromatograph in turn, finally copigmentation of leucine, cysteine, tryptophan, and methionine on C3G was studied by spectrophotometry and color difference measurement. The results showed that the optimum extraction conditions were: citric acid concentration 3.5%, enzyme type α-amylase, enzyme addition 95 U/mL, temperature 50˚C, time 125 min, and liquid-solid ratio 14:1 mL/g. Under this condition, the average yield of anthocyanins was 1.725‰, while the purity was 71.24%. Four amino acids increased the color stability of C3G and improvement with cysteine was the most significant. Therefore, enzymatic extraction of anthocyanins is an effective extraction method, and the auxiliary color of amino acids plays an important role in expanding the application range of anthocyanins.