Abstract Moisture profiles evolution of a cellular food product (potato) and two non-cellular food models made with maltodextrins (DE19 and DE36) were investigated during air-drying at two different temperatures, 25 °C and 55 °C. MRI results of suggested a non-uniform moisture distribution within potato, whilst the non-cellular food models had a more uniform profile. As expected, temperature had an impact on the drying kinetics and on the pore formation. While temperature had no impact on dry layer development for potato, it had a major impact on dry layer development for non-cellular food models. The fact that the two non-cellular food models used in this study have different glass transition temperatures but presented the same dry layer development curve does not support the hypothesis that glass transition is the driver mechanism for dry layer formation. The applicability of Fick's law was assessed by fitting experimental moisture profile data to quadratic polynomials. Fick's law provided a fairly accurate estimation of the water profiles of materials having different glass transition temperatures only when the dry layer at the surface was not taken into account, and more specifically during the middle stages of drying.

中文翻译：

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风干过程中经历玻璃化转变的食品模型的水分分布分析

摘要 研究了在 25 °C 和 55 °C 两种不同温度下风干期间，一种细胞食品（马铃薯）和两种由麦芽糖糊精（DE19 和 DE36）制成的非细胞食品模型的水分分布变化。MRI 结果表明马铃薯内的水分分布不均匀，而非细胞食物模型具有更均匀的轮廓。正如预期的那样，温度对干燥动力学和孔隙形成有影响。虽然温度对马铃薯的干层发育没有影响，但它对非细胞食物模型的干层发育有重大影响。本研究中使用的两种非细胞食物模型具有不同的玻璃化转变温度但呈现相同的干层发展曲线这一事实不支持玻璃化转变是干层形成的驱动机制的假设。菲克定律的适用性是通过将实验水分剖面数据拟合到二次多项式来评估的。菲克定律提供了对具有不同玻璃化转变温度的材料的水分布的相当准确的估计，仅当不考虑表面的干燥层时，更具体地说是在干燥的中间阶段。