响应面法优化香菇热风-微波联合干燥工艺

本文基于热风-微波分段联合干燥方式,探讨了联合干燥转换点干基含水率(2.00~5.00 g/g)、热风温度(50.0~70.0 ℃)及微波功率密度(6.67~33.33 W/g)对香菇营养成分、干燥特性及品质的影响。通过单因素实验确定较优参数范围并采用Box-Behnken组合设计优化联合干燥工艺,分析干燥工艺对干燥时间及香菇典型品质(色差、收缩率及多糖保留率)的影响。结果表明,通过响应面优化试验获得最优工艺为转换点干基含水率4.20 g/g、热风温度60.60 ℃、微波功率密度30.00 W/g,此条件下的联合干燥时间为178.33 min(其中热风干燥170 min,微波干燥8.33 min),产品色差ΔE为11.21,收缩率为65.28%,多糖保留率为66.98%,综合评分为0.145。研究结果表明热风-微波联合工艺能够实现对香菇的快速干燥,并保证较好的干品品质。

Optimization of Hot Air-microwave Combined Drying Process of Shiitakes by Response Surface Method

Hot air-microwave combined drying process was used to dry shiitakes in the current study.Effects of switching point ( dry basis moisture contents 2.00~5.00 g /g),hot air temperature( 50.0~70.0 ℃) and microwave power density( 6.67~33.33 W/g) on the drying characteristics and quality of shiitakes were investigated.Single factor experiments combined with Box-Behnken design was used to optimize the process parameters of hot air-microwave drying process.Effects of dry process on total drying time,and quality of final products( color,shrinkage,polysaccharide retention) were analyzed.Results showed that the optimal parameters for this combined drying process for shiitakes were:Dry basis moisture content at switching point 4.20 g /g,hot air temperature 60.60 ℃ and microwave power density 30.00 W/g,and the corresponding drying time was 178.33 min( the hot air was dried for 170 min and the microwave was dried for 8.33 min),total color difference was 11.21,shrinkage was 65.28%, lentinan retention was 66.98%,and the overall score was 0.145.This study suggested that the hot air-microwave combination could be an effective drying method to obtain dehydrated shiitakes with high quality.