Influences of Blanching and Freezing Pretreatments on Moisture Diffusivity and Quality Attributes of Pumpkin Slices During Convective Air-Drying
Influences of Blanching and Freezing Pretreatments on Moisture Diffusivity and Quality Attributes of Pumpkin Slices During Convective Air-Drying
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DOI：
10.1007/s11947-019-02340-9
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发表时间：
2019-11-01
影响因子：
5.6
通讯作者：
Okadome, Hiroshi
中科院分区：
文献类型：
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作者：
Ando, Yasumasa;Okunishi, Tomoya;Okadome, Hiroshi
本研究以南瓜片为研究对象，通过热烫和冷冻预处理，探讨了对流空气干燥过程中水分扩散系数与南瓜片细胞结构及品质特性之间的关系，为设计合理的干燥和预处理条件提供必要的依据。结果表明，松散的约束结构的细胞壁，由于热烫和组织中形成的冰晶在冷冻过程中增加水分扩散率的孔。此外，电阻抗分析表明，预处理对细胞膜的功能和结构损伤可能与干燥过程中的水分扩散有关。特别是，通过热烫和冷冻预处理的样品显示出显着更高的值相比，其他样品的水分扩散率。关于质量属性，由于在热烫过程中淀粉糊化的颜色亮度的下降显着影响干燥产品的颜色特性。淀粉糊化由于热烫和冷冻过程中形成的孔隙显着影响干燥后的样品的结构，从而影响复水率和力学性能。
In this study, the relationship between moisture diffusivity in convective air-drying and cellular structure through blanching and freezing pretreatment and quality attributes of dried pumpkin slices were evaluated to obtain necessary information for designing appropriate drying and pretreatment conditions. The results suggest that the loosely bound structure of cell walls due to blanching and pores in the tissue formed by ice crystals during freezing increased moisture diffusivity. In addition, the functional and structural damage of cell membranes by the pretreatments, shown by the electrical impedance analysis, is likely involved in moisture diffusivity during drying. In particular, the sample pretreated by both blanching and freezing showed significantly higher values of moisture diffusivity compared to other samples. With regards to quality attributes, a decrease in color lightness due to starch gelatinization during blanching dramatically affected the color characteristics of the dried product. Starch gelatinization due to blanching and the formation of pores during freezing significantly influenced the structure of the samples after drying, which affected the rehydration rates and mechanical properties.