Abstract

The aim of present work was mainly to study the influence of blanching-freezing pre-treatment on moisture removal characteristics of potato during microwave drying process. The influence of microwave power and the samples thickness was also assessed. For this purpose, microwave powers of 100, 350 and 550 W were practiced to dry discoid shape samples of fresh and blanched-frozen potatoes with a constant diameter of 20 mm and different thicknesses of 5, 10 and 15 mm. The obtained results revealed that time required to dehydrate treated potatoes was significantly (P < 0.05) shorter than the fresh ones. The moisture diffusivity of the fresh and blanched-frozen potatoes was determined to be in the range of 9.13 × 10⁻⁹‒7.93 × 10⁻⁸ and 9.89 × 10⁻⁹‒9.36 × 10⁻⁸ m² s⁻¹, respectively where enhanced with the both increasing power level and samples thickness. The average energy required to instigate water diffusion inside the treated samples with 5, 10 and 15 mm thickness was obtained to be 0.463, 0.379 and 0.331 W g⁻¹, respectively while the values for fresh samples were 0.505, 0.466 and 0.413 W g⁻¹, respectively.

摘要

本工作的目的主要是研究热烫-冷冻预处理对微波干燥过程中马铃薯水分去除特性的影响。还评估了微波功率和样品厚度的影响。为此，使用 100、350 和 550 W 的微波功率来干燥直径恒定为 20 mm 和不同厚度为 5、10 和 15 mm 的新鲜和热烫冷冻马铃薯的盘状样品。结果表明，处理过的马铃薯脱水所需的时间明显 短于新鲜马铃薯（ P < 0.05）。新鲜和漂烫冷冻马铃薯的水分扩散率确定在 9.13 × 10 ^-9 ‒7.93 × 10 ^-8和 9.89 × 10 ^-9范围内‒9.36 × 10 ^-8 m ² s ^-1，分别随着功率水平和样品厚度的增加而增强。在厚度为 5、10 和 15 mm 的处理过的样品内引发水扩散所需的平均能量分别为 0.463、0.379 和 0.331 W g ^-1，而新鲜样品的值为 0.505、0.466 和 0.413 W g ^{- 1}，分别。