Water sorption isotherms and glass transition in strawberries: influence of pretreatment
Water sorption isotherms and glass transition in strawberries: influence of pretreatment
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DOI：
10.1016/s0260-8774(03)00245-0
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发表时间：
2004-05
影响因子：
5.5
通讯作者：
G. Moraga;N. Martínez‐Navarrete;A. Chiralt
中科院分区：
文献类型：
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作者：
G. Moraga;N. Martínez‐Navarrete;A. Chiralt
草莓的吸水等温线和玻璃化转变随水分含量的变化作为样品前处理的函数进行了测定。吸附实验是在30℃的受控AW值下进行的，研究的样品是完整和均质的组织、新鲜的(用于解吸过程)和预先冷冻干燥的(用于吸附过程)。用差示扫描量热仪分析了平衡到不同水分含量的样品的玻璃化转变。吸附数据用GAB模型拟合，水的塑化效应用Gordon和Taylor方程模拟。草莓的预处理引起了组织结构的变化，这些变化影响了不同产品相在一定的aw值下的平衡保水能力。这意味着产品的平均平衡含水率与非晶态可溶固体的aw值(平衡时的所有相都相等)和玻璃化转变温度之间的关系存在差异。
Water sorption isotherms and glass transition as a function of moisture content were determined in strawberries as a function of sample pretreatment. Sorption experiments were carried out in chambers at controlled aw, at 30 °C. Samples studied were whole and homogenized tissue, fresh (for the desorption process) and previously freeze-dried (for the adsorption process). Glass transition of samples equilibrated to different moisture contents were analysed by DSC. GAB model was fitted to sorption data and Gordon and Taylor equation was used to model the water plasticization effect. Strawberry pretreatments caused changes in the tissue structure that affected the water binding capacity of the different product phases at equilibrium with a determined awvalue. This implied differences in the relationships between the mean equilibrium moisture content of the product and both the awvalue (equal for all phases at equilibrium) and glass transition temperature of the amorphous soluble solids.