潮州“后陇红”番薯皮色素的提取及其稳定性分析

以"后陇红"番薯皮为原料,提取色素,并对其稳定性进行研究分析。实验结果表明,色素最佳提取工艺为:提取剂1%盐酸乙醇(V/V),浸提温度为60℃,时间为5h,料液比为1∶500。稳定性研究表明,该色素具有良好的热稳定性、抗氧化性和抗还原性。常用的食品添加剂如糖类,对该色素的色泽没有大的不良影响,其中苯甲酸钠,柠檬酸,抗坏血酸对色素的影响相对较大,因此其用量不宜过多。日光对色素的影响很大,所以在生产和储存过程中要避免阳光直射。金属离子中Ca2+,Mg2+对色素的影响较大,其他金属离子如K+、Na+、Zn2+、Fe3+、Cu2+对色素无大影响。该色素有较强的耐酸性,但不耐碱,当pH为12时,色素明显变色且有大量沉淀物,若溶液用酸调至酸性时,即恢复原来的颜色。

The Extraction of Chaozhou Houlonghong Sweet Potatoes Skin Pigment and the Research of its Stability

In the paper,we use Houlonghong Sweet Potatoes Skin as raw materials to extract pigment,and analyze its stability of the red pigment.The studies show that the best extraction technology is 1% Hydrochloric acid ethanol,60 ℃,5 h and the ratio of solid and liquid as 1∶500.Stability research shows that the pigment has fine heat stability,oxidative stability and reducing stability.Common food additives,such as sugar,have little negative effect on the pigment.Nevertheless,sodium benzoate,citric acid and ascorbic acid has the a slight impact on it,so these food additives shouldn’t be used too much.Sunlight has great influence on the pigment,hence direct sunlight should be avoided in the process of production and storage.Ca2+,Mg2+ have greater influence on the pigment than others including K+,Na+,Zn2+,Fe3+,Cu2+ etc.The pigment shows strong acid resistance,but alkali resistance intolerance.when pH values at 12,the pigment changed its color obviously with a large amount of sediment.When pH values no more than 7,the pigment would recover its original color.