千根草红色素的提取及其稳定性研究

Extraction and Stability Study on Euphorbia Thymifolia Red Pigment

研究了千根草红色素的提取条件和稳定性。以乙醇作提取剂，用紫外分析法研究色素的稳定性。得到乙醇提取的适宜工艺条件是：以pH=3的65％乙醇溶液，原料与乙醇的质量与体积比为1：10，在室温下浸提24h。色素在320nm有最大吸收峰，该色素水溶性较好，在pH值1～9时具有良好的稳定性，热稳定性也良好。蔗糖、葡葡糖和盐等食品添加剂对色素无影响，但淀粉对其影响较大，耐光性较差。影响明显的氧化剂有（NH4）2S2O8、还原剂有抗坏血酸，金属离子对其影响较大。

The extraction condition from Euphorbia thymifolia and the stability of red pigment was studied. Ethanol was used as the extractant in the extraction, and the pigment stability was investigated by UV spectrum. The optimum conditions for ethanol extraction were： 65 % ethanol was used as the extractant （ pH= 3）, and lg material was extracted in 10mL extractant under room temperature for 24h. The λmax for the pigment was at 440nm, which had good solubility in water, and excellent stability in the extractant （pH 1--9） for wide temperature scope, bad light resistance characteritics was observed, however. Some common food additive, such as cane sugar, glucose and salt, had no effect on the stability of the pigment, except for starch, （NH4）2S2O8 （oxidant）, vitamin C （reducing agent） and metallic ions.