金叶榆叶片黄色素的提取及性质研究

Research on Extraction and Properties of the Pigment of Ulmus pumila Leaves

为了明确金叶榆(Ulmus pumila)叶片中黄色素的适宜提取试剂及黄色素的理化性质,采用分光光度计法测定不同溶液提取黄色素的吸光度。结果表明:金叶榆叶片中黄色素的适宜提取试剂为乙醇,吸收波长为440nm。呈色反应表明黄色素中含有类胡萝卜素和黄酮类物质。稳定性研究表明金叶榆的黄色素对热较稳定,80℃以下2h色素颜色变化不明显;黄色素对光不稳定,全光照处理2h后吸光度仅保持11.5%,贮存时宜避光;黄色素在弱酸、弱碱和大部分金属离子条件下稳定,还原剂、氧化剂及Al3+对色素具有不利影响。以上研究表明,金叶榆黄色素具有一定的开发利用价值,这为充分开发利用金叶榆资源,增加其经济附加值以及开拓新的天然食品着色剂提供了理论依据。

Taking Ulmus pumila leaf as material, the physiochemical properties and the suitable reagent of the pigment from Ulmus pumila leaf was investigated in this study. The extraction solvent kind and the change in maximum absorption wavelength of this pigment under different conditions were determined through a speetrophotometer. The results showed that the suitable reagent for the extraction was ethanol. The pigments dissolved in ethanol exhibited a maximum absorption at 440 nm wavelength. The color generation manifest that the yellow pigment contained carotenoids and flavonoids. The pigments had poor light stability. The absorbance only maintained 11.5 % after 2 hours reaction and consequently should be stored in the dark condition. After 2 hours exposure to a temperature below 80℃, a low degradation ratio was observed in the pigments. The pigments were stable in acidic and alkalescent media. There were negative influences of light,oxidants, deoxidants and Al^3 ＋ on the yellow pigment. These investigations demonstrated that the pigment had the exploitation and utilization values. These results had provided a new theoretical basis for the full utilization of Uhnus pumila resources,increasing its economic value and the exploration of natural food colorants.