浸泡与米水比例对预烹调小米微波对流恒温干燥特性与品质的影响

Influence of soaking and millet/water ratio on microwave-convective drying characteristics and quality of cooked millet under the constant temperature

以微波对流恒温组合干燥技术干燥预烹调小米,考察高压汽蒸前米水比例与浸泡对方便小米微波对流恒温干燥动力学及产品品质的影响。结果表明,整个干燥过程受扩散控制,以两阶段降速干燥为特征,基于经验的Henderson and Pabis模型可以预测小米干燥过程的水分含量(R^2>0.971 4),菲克扩散定律计算得到的有效水分扩散系数在3.30×10^(-7)~5.03×10^(-7) m^2/s;以米水比1.5:1(g/mL)常温浸泡3h后,获得的方便小米产品具有最高的感官评分,其特征色值L~*、a~*、b~*、C~*、h°分别为45.75,7.56,38.93,38.19,78.84°,总色差为31.64,复水比最大(2.48),复水时间4.2min。

In this study,the cooked millet was dried using microwave-convective drying under the constant temperature and the effect of soaking and millet/water ratio before pressure cooking millet on the drying kinetics and quality of dried millet were investigated.The results showed that the whole drying process was controlled by diffusion and characterized by two stage falling rate drying.The moisture content during millet drying was predicted by the experienced Henderson and Pabis modle（R^2〉0.971 4）and the effective moisture diffusivity calculated by Fick＇s law of diffusion was in the range of 3.30×10^-7 m^2/s to 5.03×10^-7 m^2/s.The best sensory quality was obtained when the ratio of millet to water was 1.5：1（g/mL）and the millet was dipped for 3h,in which the value of L^＊,a^＊,b^＊,C^＊,h°andΔE was 45.75,7.56,38.93,38.19,78.84°and 31.64 respectively.Under this condition,the rehydration ratio of millet was the highest（2.48）,and it could be rehydrated in 4.2min.