CAJ | 학술논문

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。
위료종합수분활도급파리화전변이론구건상태도，획득회조분적교가저장조건，해문채용정태칭량법화차시소묘량열법측정회조분적흡부특성급파리화전변온도。결과표명，팽화간조회조분수분흡부적평형간기함수솔수수분활도적증가이증가，수분흡부등온선정J형，묘술회조분수분흡부특성적괄의모형위GAB모형（R2=0.9968）；회조분적파리화전변온도수함수솔승고이강저，습기함수솔유0.064증가도0.175 g/g시，파리화전변온도유29.90강저도?35.02℃；회조분간기함수솔≤0.1223 g/g、저장온도≤?0.062°C시기은정성교호，연구결과위회조분가공、운수등과정중적저장조건제공이론삼고。
Since the 1980s, 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 temperaturedata, respectively. The state diagram of jujube powder was developed using the fitted moisture sorption isotherm and glass transition temperature curve to determine the suitable storage condition. Results showed that the equilibrium moisture content of explosion puffing dried jujube powder increased with the increasing of water activity, and the equilibrium moisture content (dry basis) was increased from 0.06 to 0.76 g/g as water activity increased from 0.113 to 0.902. The sorption behavior displayed “J” type isotherms, which may be due to the high sugar content of jujube powder. The best model to describe the moisture sorption isotherm characteristics of jujube powder was GAB model (R2=0.9968). The fitting curve indicated great fitting effect. The glass transition temperature was decreased with the increasing of moisture content, and the glass transition temperaturewas decreased from 29.90 to -35.02℃ as moisture content (wet basis) of jujube powder was increased from 0.064 to 0.175 g/g. The Gordon-Taylor equation was used to fit the glass transition temperature nonlinearly, and the correlation coefficient (R2) was 0.9912, which revealed good fitness. When dry basis moisture content was at or below 0.1223 g/g, and the temperature was at or below -0.062℃, the storage condition was suitable for jujube powder.