绿豆清爽饮料制备中护色剂选择及总黄酮含量测定

目的：在制备绿豆清爽饮料过程中,确定护色效果好且总黄酮提取率高的护色剂最佳配方。方法：对护色剂柠檬酸钠、异VC钠、三聚磷酸钠单独使用及其复合配方的护色效果和总黄酮含量进行单因素及正交试验研究,总黄酮含量采用分光光度法测定。结果：三种护色剂柠檬酸钠、异VC钠和三聚磷酸钠复合使用时均显著影响护色效果,对绿豆中总黄酮的提取率也有显著影响,各因素影响顺序为柠檬酸钠〉异VC钠〉三聚磷酸钠;得出最佳护色剂配比为：柠檬酸钠0.02%、异VC钠0.018%和三聚磷酸钠0.1%;通过重复试验制备的绿豆清爽饮料中的总黄酮含量为12.8±0.42mg/L。结论：柠檬酸钠的酸度调节作用、异VC钠的抗氧化作用和三聚磷酸钠的螯合作用,三者结合后方可显著提高绿豆色素的稳定性。

Selection of color protection agents and determination of total flavonoids in preparation of refreshing mung bean beverages

Objective:To determine the optimal combination of color protection agents both effective in color protection and helpful to high extraction rate of total flavonoids in the preparation of refreshing mung bean beverages.Method:Single-factor and orthogonal experiments were carried out to study color protection effects and total flavonoids contents in the case of color protection agents sodium citrate,sodium D-isoascorbate and sodium tripolyphosphate used alone or in combination.The total flavonoids contents were determined by spectrophotometry.Results:Sodium citrate,sodium D-isoascorbate and sodium tripolyphosphate used in combination had a significant influence on not only color protection effects but also the extraction rate of total flavonoids from mung bean,with the sequence of influence as sodium citrate > sodium D-isoascorbate > sodium tripolyphosphate;the optimum combination of color protection agents was determined as 0.02% sodium citrate,0.018% sodium D-isoascorbate and 0.1% sodium tripolyphosphate;the total flavonoids content in refreshing mung bean beverages prepared in repeated experiments was 12.8 ± 0.42 mg/L.Conclusion:Only in combination can the acidity regulating effect of sodium citrate,the anti-oxidation effect of sodium D-isoascorbate and the chelation effect of sodium tripolyphosphate significantly improve the stability of mung bean pigment.