植物组织的复水动力学模型

Modeling of Rehydration Kinetics of Plant Tissue

针对植物物料组织结构所具有的细胞内空间和细胞外空间的典型特征 ,分析了植物组织在复水过程中的水分迁移特性。根据提出的流动区域与非流动区域概念 ,建立了植物组织复水的一级两项动力学模型。通过试验测定云豆在 30℃和 4 5℃条件下的复水动力学曲线 ,并对试验结果进行拟合 ,拟合曲线与试验结果吻合 ,回归系数分别为 0 .998和 0 .995 ,表明该模型能够很好地表达植物组织复水动力学过程。增加复水温度可提高流动区域的平衡含水率 ,提高流动区域、非流动区域水分质量传递速率常数 ,缩短复水时间 ,可提高植物组织总平衡含水率。

Inter-cellular spaces and individual intra-cellular spaces consist of typical tissue structure of plant material. The passages for water migration are well connected in inter-cellular spaces and water migration into these pores only needs to overcome the capillary resistance. So, intercellular spaces can be defined as mobile region. For the closed pores of intact cells, water migration into these cells is via the permeable flow through the cell wall. There is much greater resistance for water migration into the discrete pores of the intra-cellular spaces, because the orders of water channels through cell walls are magnitude smaller than the inter-cellular spaces. Therefore, intra-cellular spaces can be defined as stagnant region. Based on above proposed concepts of mobile region and stagnant region, a two-component first-order rehydration kinetic model was established. The rehydration kinetic curves of red kidney bean, soaked at 30°C and 45°C respectively, were obtained. The results from the model and the experiments coincide with each other and the regression coefficients were 0.998 and 0.995 respectively. Increasing rehydration temperature could hasten water mass transfer, lead to a high equilibrium water content in intra-cellular spaces, and raise water mass transfer constants.