微波-热风联用制取笋干工艺条件优化

Optimization of Combined Microwave-Hot Air Drying Process of Bamboo Shoots

为获得干燥时间短、干燥品质好的笋干,以竹笋为原料,在单因素试验的基础上,根据中心组合试验设计原理,分析微波干燥功率、微波干燥时间和热风干燥温度3 个因素对笋干感官评分、总干燥时间、复水比、色差和硬度指标的影响,以确定微波-热风联用制取笋干最佳工艺条件。结果表明,制取笋干的最佳工艺条件为:微波干燥功率6.3 W/g、微波干燥时间60 s、热风干燥温度65 ℃。在此条件下得到的笋干感官评分85.6、总干燥时间200 min、复水比6.17,干制品色差ΔE* 19.99、复水制品色差ΔE* 13.92、干制品硬度19 511.23 g、复水制品硬度20 010.71 g,该工艺研究结果可为笋干产业化发展提供理论支持。

In order to reduce the drying time and at the same time to improve the quality of dried bamboo shoots, a combined microwave-hot air drying process was developed and optimized by examining the effect of microwave drying time and power and hot air drying temperature on sensory score, total drying time, rehydration rate, color difference and hardness using a combination of single factor method and central composite design coupled with response surface methodology. The results showed that the optimal drying conditions were as follows: microwave power, 6.3 W/g;microwave drying time, 60 s;and hot air drying temperature, 65 ℃. Under these conditions, the sensory score of dried bamboo shoots was 85.6 points, the total drying time was 200 min, and the rehydration rate was 6.17;the color difference ΔE* and hardness were 19.99 and 19 511.23 g, while those of the rehydrated product were 13.92 and 20 010.71 g, respectively. The proposed drying process will be of great significance to the future development of the bamboo shoot industry.