Abano Ernest Ekow
Department of Agricultural Engineering, School of Agriculture, College of Agricultural and Natural Sciences, University of Cape Coast, Cape Coast, Ghana.
Int J Food Sci. 2016;2016:2037029. doi: 10.1155/2016/2037029. Epub 2016 Jan 3.
The effect of microwave-assisted convective air-drying on the drying kinetics and quality of mango was evaluated. Both microwave power and pretreatment time were significant factors but the effect of power was more profound. Increase in microwave power and pretreatment time had a positive effect on drying time. The nonenzymatic browning index of the fresh samples increased from 0.29 to 0.60 while the ascorbic acid content decreased with increase in microwave power and time from 3.84 mg/100g to 1.67 mg/100g. The effective moisture diffusivity varied from 1.45 × 10(-9) to 2.13 × 10(-9) m(2)/s for microwave power range of 300-600 W for 2 to 4 minutes of pretreatment. The Arrhenius type power-dependent activation energy was found to be in the range of 8.58-17.48 W/mm. The fitting of commonly used drying models to the drying data showed the Midilli et al. model as the best. Microwave power of 300 W and pretreatment time of 4 minutes emerged as the optimum conditions prior to air-drying at 7°C. At this ideal condition, the energy savings as a result of microwave application was approximately 30%. Therefore, microwave-assisted drying should be considered for improved heat and mass transfer processes during drying to produce dried mangoes with better quality.
评估了微波辅助对流空气干燥对芒果干燥动力学和品质的影响。微波功率和预处理时间都是显著因素，但功率的影响更为显著。微波功率和预处理时间的增加对干燥时间有积极影响。新鲜样品的非酶褐变指数从0.29增加到0.60，而随着微波功率和时间的增加，抗坏血酸含量从3.84毫克/100克降至1.67毫克/100克。对于300 - 600瓦微波功率范围和2至4分钟预处理时间，有效水分扩散率在1.45×10(-9)至2.13×10(-9)平方米/秒之间变化。发现阿累尼乌斯型功率依赖活化能在8.58 - 17.48瓦/毫米范围内。常用干燥模型对干燥数据的拟合表明米迪利等人的模型是最佳的。300瓦微波功率和4分钟预处理时间是在7°C空气干燥之前的最佳条件。在这个理想条件下，由于应用微波而节省的能量约为30%。因此，在干燥过程中为改善传热传质过程以生产质量更好的芒果干，应考虑采用微波辅助干燥。
