膨化干燥灰枣粉玻璃化转变及贮藏稳定性  

Glass transition and storage stability for explosion puffing dried jujube powder

作　　者：毕延娣 陈芹芹[2] 毕金峰[1,2] 颜廷才[1] 吴昕烨[2] 赵悦[1,2] 

机构地区：[1]沈阳农业大学食品学院,沈阳110866 [2]中国农业科学院农产品加工研究所农业部农产品加工重点实验室,北京100193

出　　处：《农业工程学报》2015年第21期265-270,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(31401508);国家"十二五"科技支撑计划课题"复合果蔬新产品创制与节能减排关键技术开发及示范"(2012BAD31B06)

摘　　要：为了综合水分活度及玻璃化转变理论构建状态图,获得灰枣粉的较佳贮藏条件,该文采用静态称量法和差示扫描量热法测定灰枣粉的吸附特性及玻璃化转变温度。结果表明,膨化干燥灰枣粉水分吸附的平衡干基含水率随水分活度的增加而增加,水分吸附等温线呈J型,描述灰枣粉水分吸附特性的适宜模型为GAB模型(R2=0.9968);灰枣粉的玻璃化转变温度随含水率升高而降低,湿基含水率由0.064增加到0.175 g/g时,玻璃化转变温度由29.90降低到-35.02℃;灰枣粉干基含水率≤0.1223 g/g、贮藏温度≤-0.062°C时其稳定性较好,研究结果为灰枣粉加工、运输等过程中的贮藏条件提供理论参考。Since the 1980 s, water activity has been commonly used to evaluate the food storage stability, and food storage will be more stable in or below the moisture content of monolayer molecular layer. Water activity is related to the composition, temperature and physical state of the compounds, and the physical state of food compounds is also related to the stability. But recently, some scholars had found the limitations of using water activity to assess the food storage stability, so the glass transition theory was proposed. Glass transition is a well-known change in the state of amorphous materials, and the characteristic temperature is the glass transition temperature. When the temperature is lower than the glass transition temperature, the system is in glass state, energy is low, viscosity is high, and the molecular chain is segmented into ＂frozen＂ state, so the system is relatively stable. On the contrary, when the system temperature is higher than the glass transition temperature, the system is in rubbery state, which leads to the viscosity reduction, the free volume increasing and a variety of changes in motion by diffusion-controlled reactions acceleration, so the system is unstable. Therefore, food in glass state is often considered to be stable, and the glass transition temperature has become an important predictor of food quality. With the deep understanding of water activity and glass transition theory, more and more scholars had combined these 2 theories together to predict the stability of food storage. In order to investigate the suitable storage condition of explosion puffing dried jujube（Zizyphus jujube cv. Huizao） powder, moisture sorption isotherm and glass transition temperature were determined at 25°C by the gravimetric method and differential scanning calorimetry, respectively. Three water sorption models and Gordon-Taylor equation were used to fit the moisture sorption isotherms and the glass transition temperature data, respectively. The state diagram of jujube powder was developed usi

关 键 词：贮藏 温度 水分 灰枣粉 吸附等温线 玻璃化转变温度 状态图 

分 类 号：TS255.4[轻工技术与工程—农产品加工及贮藏工程]