核桃青果皮色素成分分析及稳定性研究

Study on Components Analysis and Stability of Pigment from Walnut Green Husks

为开发利用天然色素,提取核桃青果皮色素:在合适的条件下利用超声萃取的方法提取色素,并用酸沉法使色素析出,干燥得到固体。对色素中的主要染色成分进行分析,并对色素稳定性进行研究。结果表明:该色素中单宁和黄酮的平均含量分别为28.07%和4.86%;具有较好的耐热性和耐光性;在酸性条件下产生沉淀,碱性条件下溶液颜色加深;H2O2对其有一定影响而,Na2SO3对其没有影响;金属离子Na+、K+对色素色泽无明显影响,而Ca2+、Al3+、Cu2+、Fe3+与色素分子形成络合物。

For development and utilization of natural pigment, the conditions for extracting a natural pigment from walnut green husks were explored： extracting the pigment by ultrasonic extraction under suitable conditions, and then the pigment was separated out with adding acid, dried for powder. Content of tannin and flavonoids which were main dyeing composition were determined, and stability of the pigment was studied. The result showed that the average content of tannin and flavonoids were 28.07%, 4.86% respectively. The pigment was heat-resistant and lightfast. There was sediment when the pigment was in acid condition, and the color became darker in alkaline condition. H2O2 had a certain impact on the stability of the pigment while Na2S03 had not. Na＋, K＋ had no significant impact on the color of pigment, but Ca2＋,Al^3＋、Cu^2＋.Fe^3＋ could form the complex with the molecules of pigment.