本文已被:浏览 254次 下载 0次
投稿时间:2015-06-08
投稿时间:2015-06-08
中文摘要: 为研究紫青稞色素的稳定性,在不同温度(70、80、90℃)和pH值(1、3、5、7)条件下检测其降解过程。结果发现该色素的降解速率与加热时间呈线性关系,符合一级动力学特征。该色素的稳定性同时受温度和pH影响,在较低温度和较低pH条件下稳定性较强。在70℃~90℃范围内,pH值为1,3,5和7时,紫青稞色素的半衰期t1/2分别为23.8 h~9.1 h、16.5 h~6.9 h、13.5 h~6.8 h、16.8 h~7.5 h,活化能Ea分别为49.68、45.37、35.55、41.84 kJ/mol。此外,紫青稞色素提取液的降解生成褐色物质,褐变指数随加热时间的延长、加热温度的升高、pH值的增大而增大。
Abstract:In the present study,thermalsta bility of anthocyanins from purple hulless barley was investigated at three temperatures(70,80,90℃)and four pH values(1,3,5,and 7).Results indicated that the degradation kinetics of hulless barley anthocyanins followed first-order reaction kinetics.The thermal degradation of hulless barley anthocyanins was temperature and pH dependent,and the anthocyanins were more stable during heating at lower temperature and pH.The calculated values ofhalf-lives t1/2were 23.8 h-9.1 h,16.5 h-6.9 h,13.5 h-6.8 h,16.8 h-7.5 h and the activation energies(Ea)were 49.68,45.37,35.55,41.84 kJ/molfor anthocyanins atpH 1,3,5 and 7,respectively.Besides,brown compounds appeared in the pigment extracts during heating,and the brown indices ofthe extracts increased with increasing oftime,temperature and pH.
keywords: anthocyanins stability kinetics hulless barley
文章编号:201612006 中图分类号: 文献标志码:
基金项目:上海工程技术大学高水平项目培育基金(2012gp10);上海市大学生创新活动计划项目(cs1404009);上海工程技术大学大学生创新活动计划项目(cx1404004)
引用文本: