微波辅助提取中pH值与脱色对苹果果胶的影响  

Effect of pH and decoloring on apple pectin extraction with microwave-assisted

作　　者：曹霞敏[1] 周林燕[1] 吴继红[1] 张燕[1] 廖小军[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院果蔬加工教育部工程研究中心农业部果蔬加工重点开放实验室,北京100083

出　　处：《农业工程学报》2010年第S2期410-415,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：农业部"948"项目-果胶产业化关键技术(No.2005-Z33);国家"十一五"支撑计划课题-苹果果胶系列产品与优质苹果汁开发及产业化示范(2006BAD05A13)

摘　　要：为了得到高得率、高品质的苹果果胶,该文利用不同pH值的盐酸溶液对苹果渣中果胶进行微波辅助提取(Microwave-assisted extraction,MAE),之后对果胶提取液进行大孔树脂XAD-16HP脱色,研究了pH值与脱色对果胶得率和品质的影响。结果表明:微波辅助提取工艺中随着pH值的升高,果胶得率、半乳糖醛酸质量分数和总离子含量减少,酯化度、黏均分子量和总多酚增加,褐变度无显著变化;大孔树脂吸附脱色后果胶褐变度、总多酚、彩度C*值显著下降,色调角H°值显著增加,半乳糖醛酸质量分数和酯化度没有变化;经脱色处理后,果胶半乳糖醛酸含量和酯化度都没有明显的变化,褐变度和酚类物质含量减少,颜色品质得到改善。综合以上,pH值为1.50条件下所得的果胶既能达到10.78%的得率,又能较大程度地提高苹果果胶的品质。In order to improve the yield and quality of apple pectin,the effects of extraction pH by microwave-assisted extraction(MAE) and decoloring by using adsorption of resin were studied systematically by evaluating the yield and quality of apple pectin.The results showed that the higher pH,the lower yield of apple pectin,total mineral contents and galacturonic acid(GA),However,the higher degree of esterification(DE) and average molecular weight.The polyphenols in extracted pectin was increased as pH increased by MAE,indicating that higher pH was beneficial to extract polyphenols from apple pomace.Further investigations indicated that the GA and DE of the pectin recovered from apple pomace didn't change significantly after decolourisation among all the treatments.The a*,b*,C* value,browning index and total phenolic content of decoloured sample significantly decreased while the H° value increased,which showed that decolourisation by using adsorption of resin significantly improved the color of apple pectin.It can be concluded that the parameters of pH=1.50 provide one of the most promising conditions for extracting pectin from apple pomace.

关 键 词：微波 提取 农业废弃物 苹果渣 果胶 PH值 

分 类 号：TS255.36[轻工技术与工程—农产品加工及贮藏工程]