紫荆花精制红色素稳定性和理化性质的研究

目的探讨纯化的紫荆花红色素的稳定性和理化性质。方法用分光光度法。结果紫荆花红色素属花色苷类，最大吸收波长526nm，易溶于水等极性溶剂，不溶于石油醚等非极性溶剂；其水溶液颜色随pH值变化而变化，酸性条件下呈红色，PH〉10时呈褐色；耐光性、耐热性较好；蔗糖、抗坏血酸、苹果酸、柠檬酸等添加剂对其影响较小，过氧化氢、亚硫酸钠对其有一定的破坏作用，苯甲酸钠超过0．5％时色素保存率明显降低；金属离子Na^＋、Mg^2＋、Zn^2＋、Al^3＋对其稳定性无影响，Cu^2＋、Fe^2＋影响较小，Fe^3＋可使其变为褐色。结论紫荆花红色素稳定性较好，有进一步研究的价值。

Study on Stability and Physico-chemical Property of Prepared Red Pigment from Cercis chinensis Bge.

Objective To study the stability and physico-chemical property of prepared red pigment from Cercis chinensis Bge. Methods The ultraviolet-visible spectrophotometry was adopted. Results The red pigment was an anthocyanin and its maximum absorption wavelength was 526 nm. It was freely soluble in water and other polar solvents, insoluble in petroleum ether and other non-polar solvents. It＇ s color aqueous solution was changed with pH value and it was red in acidic solutions, brown at pH 〉 10. It had good photostability and thermostability, and was hardly influenced by sodium benzoate, sugar, antiscorbic acid, apple acid, citric acid, etc. But it was sensitive to H2O2, Na2SO3 and sodium benzoie acid （over 0.5 % ）. It was stable to Na^＋, Mg^2＋, Zn^2＋ and Al^3＋, and could be protected by Fe^2＋and Cu^2＋, while Fe^3＋ made it brown. Conclusion With a good stability, the red pigment from Cercis chinensis Bge. deserves the further investigation.