Bhattacharya Mrittika, Srivastav Prem Prakash, Mishra Hari Niwas
Department of Agricultural and Food Engineering (AgFE), Indian Institute of Technology, Kharagpur, West Bengal 721 302 India.
J Food Sci Technol. 2015 Apr;52(4):2013-22. doi: 10.1007/s13197-013-1209-2. Epub 2013 Nov 29.
Oyster mushroom samples were dried under selected convective, microwave-convective drying conditions in a recirculatory hot-air dryer and microwave assisted hot-air dryer (2.45 GHz, 1.5 kW) respectively. Only falling rate period and no constant rate period, was exhibited in both the drying technique. The experimental moisture loss data were fitted to selected semi-theoretical thin-layer drying equations. The mathematical models were compared according to three statistical parameters, i.e. correlation coefficient, reduced chi-square and residual mean sum of squares. Among all the models, Midilli et al. model was found to have the best fit as suggested by 0.99 of square correlation coefficient, 0.000043 of reduced-chi square and 0.0023 of residual sum of square. The highest effective moisture diffusivity varying from 10.16 × 10(-8) to 16.18 × 10(-8) m(2)/s over the temperature range was observed in microwave-convective drying at an air velocity of 1.5 m/s and the activation energy was calculated to be 16.95 kJ/mol. The above findings can aid to select the most suitable operating conditions, so as to design drying equipment accordingly.
平菇样品分别在循环热风干燥机和微波辅助热风干燥机（2.45GHz，1.5kW）中，在选定的对流、微波对流干燥条件下进行干燥。两种干燥技术均仅表现出降速阶段，而无恒速阶段。将实验得到的水分损失数据拟合到选定的半理论薄层干燥方程中。根据相关系数、约化卡方和残差均方和这三个统计参数对数学模型进行比较。在所有模型中，发现Midilli等人的模型拟合效果最佳，其平方相关系数为0.99，约化卡方为0.000043，残差平方和为0.0023。在空气流速为1.5m/s的微波对流干燥中，观察到在该温度范围内最高有效水分扩散率在10.16×10⁻⁸至16.18×10⁻⁸m²/s之间变化，计算得到的活化能为16.95kJ/mol。上述研究结果有助于选择最合适的操作条件，从而据此设计干燥设备。
