红毛丹果皮色素及其稳定性的研究

红毛丹(Nephelium lappaceum L.)果皮含有较高的色素。为综合利用植物色素资源，对红毛丹果皮色素进行提取与纯化，并从光照、温度、pH 值、氧化与还原介质、防腐剂、酸味剂、糖类、VC 和金属离子方面对该色素的稳定性进行研究。结果表明：红毛丹色素属花色苷类；对自然光、高温、H2O2 和Na2SO3 的耐受性较差，在pH3 以下色泽较稳定；低浓度防腐剂苯甲酸钠对色素稳定性影响较小，柠檬酸具有一定的增色作用；乳酸、葡萄糖和蔗糖、VC 对色素的稳定性无明显的影响，但Fe3+、Fe2+、Pb2+、Sn2+ 对该色素稳定性起不利的作用。该研究为开发植物新的天然色素产品提供理论参考。

Extraction and Stabilization of Pigments from Rambutan (Nephelium lappaceum L.) Fruit Pericarp

The crude pigments were extracted from rambutan (Nephelium lappaceum L.) fruit pericarp tissues with 80% of acidified ethanol and purified through silica gel column and Amberlite XAD-7 resin column. Factors affecting the stability of purified pigments were investigated including sunlight, temperature, pH value, oxidant, reducer, preservative, citric acid, lactic acid, glucose, sucrose, VC and metal ions. Rambutan pigments showed high similarity to anthocyanins on the absorption spectrum and exhibited a poor stability to sunlight, heat, hydrogen peroxide and sodium sulfite. Color stability was observed under pH 3 and was enhanced by addition of citric acid. However, no significant effect of sodium benzoate was found at low concentration. Lactic acid, glucose, sucrose and VC exhibited no negative effects on the stability while iron (III), iron (II), lead (II) and stannum (II) ions accelerated the degradation of the pigments.