超高压辅助酶法制备低酯果胶  

Preparation of low-methoxyl pectin by high hydrostatic pressure-assisted with enzyme methods

作　　者：赵文婷[1,2] 郭兴峰[3] 高林[1,2] 胡小松[1,2] 吴继红[1,2] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083 [2]国家果蔬加工工程技术研究中心,北京100083 [3]聊城大学农学院,聊城252059

出　　处：《农业工程学报》2015年第8期257-263,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金："十二五"国家科技支撑计划课题--柑橘加工副产物高效转化关键技术研究及产业化示范(2012BAD31B02);中国农业大学基本科研业务费专项资金项目(2013QJ035)

摘　　要：为明确超高压辅酶法在低酯果胶生产中的可行性,该研究以传统碱法为对照,研究了超高压(200、300 MPa)辅助果胶甲酯酶法对果胶的理化性质、分子量分布及流变性质的影响。结果表明,与传统碱法相比,超高压辅酶法制备的低酯果胶的表观黏度、固有黏度及黏均分子量均显著大于碱法低酯果胶(P<0.05),而黏流活化能较低(P<0.05),说明其黏-温敏感性更低。通过尺寸排阻色谱分析,超高压辅酶法制备的低酯果胶与脱酯前没有显著性差异(P>0.05),说明该法对果胶分子无降解作用。以上结果表明超高压辅酶法(200、300 MPa)避免了传统碱法的果胶分子降解,该法制备的低酯果胶黏度更高,可作为一种制备低酯果胶的高效、环保的新型技术。Low methoxyl pectin is widely applied as thickener, stabilizer and emulsifier in low calorie or dietetic foods. The main methods reported for the preparation of low methoxyl pectin from high methoxyl pectin have used four types of agents：acids, ammonia in alcohol or concentrated aqueous ammonia, alkali and pectin methyl esterase. The main disadvantage of the first two methods is the slowness of reaction. Alkaline de-esterification is rapid but the removal of methyl ester groups is accompanied by depolymerization of pectin chains. Enzymatic de-esterification represents an attractive alternative to chemical de-esterification, for it is without pollution, but it is time-consuming. Therefore, there is a need to explore new methods to produce pectin with high quality and efficiency. In this study, a novel method of high hydrostatic pressure combined with enzymatic treatment （pectin methyl esterase） was applied in pectin de-esterification. In order to find out the effect of enzymatic treatment assisted with high hydrostatic pressure on the properties of pectin and promote the industrial development of this technology, the physicochemical properties, molecular weight distribution and rheological characteristics of pectins de-esterified by this treatment were investigated and compared with conventional alkaline method. During the de-esterification process of enzymatic treatment assisted with high hydrostatic pressure of 200 and 300 MPa, the degree of de-esterification was reduced from 61.83%to 34.09%and 32.62%in 10 min, respectively. With further de-esterification, the reaction slowed down, while the de-esterification degree of pectin by alkaline method was reduced to 35.54%and decreased continuously when the period was prolonged to 20 min. Based on this experiment, two pairs of pectins with similar degree of de-esterification were prepared by the enzymatic treatment assisted with high hydrostatic pressure and conventional alkaline method, i.e. HHP-1 （200 MPa, 10 min; 34.09%±1.64%） ＆amp; AP-1 （pH 11.0, 11

关 键 词：酶 物理特性 化学特性 低酯果胶 超高压辅酶法 分子量分布 流变性质 

分 类 号：TQ914.1[化学工程]