本实验对菱角壳色素的理化性质和稳定性进行了研究。结果表明，菱角壳色素可溶解于水、乙醇、氢氧化钠等极性较强的溶剂，微溶于石油醚、苯、乙醚等非极性溶剂。pH值和温度对该色素稳定性有明显影响，金属离子Cu2+对色素有增色作用，K+、Na+、Ca2+对色素稳定性基本无影响，Fe2+、Al3+、Zn2+离子使其明显褪色。该色素耐氧性、耐光性差，耐还原性好。

Properties and stability of the pigment from water caltrop outer peel was investigated in this study. Results indicated that this pigment was easily soluble in water, sodium hydroxide and ethanol but insoluble in benzene, ether, and petroleum ether. An obvious effect of pH on stability of this pigment was observed and this pigment exhibited better stability in alkaline environments. In addition, Cu2+ revealed a color enhancement effect on this pigment, while K+, Na+, Ca2+, exhibited little effect. In contrast, Fe2+, Al3+ and Zn2+ contributed obvious adverse effects. It was found that the pigment was poor resistant to light and oxide, but the effects of heat on stability of pigment were little.