核桃外果皮色素的特性分析

【目的】研究分析核桃外果皮色素的特性,为核桃外果皮的开发利用提供依据。【方法】以核桃外果皮为原料,经碱提酸沉法初步提取纯化色素,鉴定其主要化学成分,并研究pH、加热时间、增稠剂、辅色素对核桃外果皮色素的影响,以及核桃外果皮色素在不同干燥条件下的保存稳定性。【结果】核桃外果皮色素主要成分有生物碱、酚类、黄酮类、醌类等化合物;色素在碱性条件下显色效果较好,而加热易导致色素褪色;增稠剂黄原胶和辅色素没食子酸、葡萄糖、酪氨酸对核桃外果皮色素有一定的增色作用;冷冻干燥制备的核桃外果皮色素较真空干燥和热风干燥更稳定。【结论】辅色素和干燥方法是影响核桃外果皮色素增色效果和稳定性的主要因素,在应用加工过程中应选择利于核桃外果皮色素增色和稳定保存的辅色素与干燥方法。

Properties analysis of pigment from walnut husks (Juglans regia L.)

【Objective 】The properties and drying methods of pigment from walnut husks（Juglans regia L.） were studied to provide references for the development and utilization of walnut husks. 【Method】Green husk pigment was extracted and purified from walnut husks（Juglans regia L.） by alkali extraction and acid precipitation. The main chemical compositions of green husk were identified. The effects of pH value, heating time, thickeners and copigments on green husk pigment were studied, and the stability of the pigment dried by different drying methods was also studied. 【Result】The main components of green husk pigment included alkaloids, phenols, flavones and anthraquinones. Green husk pigment was stable at alkaline condition, and heating could lead to color fading. Thickeners, gallic acid, glucose and acid hydrolyzed casein enhanced the color of pigment in a certain extent. Green husk pigment dried by freeze-drying was more stable than vacuum drying and hot air drying. 【Conclusion】Copigments and drying methods have critical effects on coloration and stability of green husk pigment, so proper copigments and drying methods should be chosen during food processing.