适宜贮藏温度和添加剂提高苹果粉稳定性  

Optimal temperature and additives improving stability of apple powder

作　　者：张雨[1] 陈义伦[1] 马超 吴茂玉 

机构地区：[1]山东农业大学食品科学与工程学院,泰安271018 [2]中华全国供销总社济南果品研究院,济南250014

出　　处：《农业工程学报》2014年第22期323-331,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金："十二五"国家科技支撑计划课题(2012BAD31B01)

摘　　要：为提高喷雾干燥苹果粉的贮藏稳定性和优化贮藏条件,基于水分活度保藏理论和玻璃化转变理论,探讨了温度及添加剂对苹果粉吸附等温线和玻璃化转变温度的影响。采用静态称量法研究了苹果粉在不同温度(5、25和45℃)下的吸附等温线;采用Lewicki、GAB、Smith、Henderson和Peleg模型拟合试验数据,得到描述苹果粉水分吸附特性的数学模型;采用差示扫描量热法测定了添加β-环糊精、麦芽糊精、可溶性淀粉和玉米淀粉的苹果粉在贮藏温度40℃达到水分平衡时的玻璃化转变温度;采用Khalloufi,El-Maslouhi,Ratti方程拟合数据,探讨添加剂对苹果粉临界水分活度和临界平衡干基含水率的影响。结果表明,GAB模型为描述苹果粉水分吸附特性的适宜模型;苹果粉的平衡干基含水率随着水分活度的增加而增加,水分活度小于0.76时随着温度的升高而降低;苹果粉的玻璃化温度随平衡干基含水率的增加而降低,添加β-环糊精的苹果粉玻璃化温度较高,不易结块,有利于提高苹果粉的贮藏稳定性。研究可为苹果粉适宜干燥技术条件和贮藏条件的确立提供参考。In order to improve the storage stability and to optimize the storage conditions, the effect of temperature and additives on the moisture adsorption isotherms and glass transition temperature of spray drying apple powders were investigated based on the water activity concept and the theory of glass transition temperature. The water activity concept and the glass transition temperature theory can be used to predict the stability of food. Monolayer water content is another functional value that relates to the amount of bound water in a solid material. This water normally varies between 0.04-0.11g/g dry solids for several dried foods. This low water content does not support microbial reactions, and hence contributes to food product stability. Food materials are fairly stable below their glass transition temperature but when the temperature rises above glass transition temperature, a solid structure is transformed to a supercooled liquid state with time-dependent flow. The use of state diagrams that indicate the material’s physical state, in combination with the sorption isotherms, helps in the prediction of food stability. Thus, the objective of this work was to provide experimental data of the state diagram and moisture absorption isotherm of spray dried apple powder produced with different temperature and additives, in order to obtain useful information about powders stability. Apple powders were produced by spray drying using different additives： β-cyclodextrin, corn starch, maltodextrin, soluble starch. Additives were then added to the filtered pulp, in a concentration of 30%（w/w）, under magnetic agitation, until complete dissolution. This concentration was selected in a preliminary study, as the minimum concentration at which it was possible to dry the juice without excessive powder stickiness on the chamber wall. Spray drying process was performed in a laboratory scale spray dryer LPG5 （XianFeng, JiangSu, China）. The feed flow rate used was 20 mL/min, inlet and outlet air temperature was 180℃ an

关 键 词：贮藏 温度 吸附 苹果粉 添加剂 水分活度 平衡干基含水率 玻璃化温度 

分 类 号：TS255.4[轻工技术与工程—农产品加工及贮藏工程] TS201.7[轻工技术与工程—食品科学与工程]