不同干燥方式对黄花菜干燥效果的影响

Impact Analysis of Different Drying Methods on Drying Effects of Daylily

将新鲜黄花菜采用自然晾干、干燥箱烘干(60、70、75、80℃)和真空冷冻干燥(75℃)进行干燥处理,分析干燥过程中黄花菜质量的变化,计算含水量、干基含水率和干燥速率,绘制相应的曲线图,对比干燥结果。结果表明:晾干工艺依赖天气情况,晴天时室内外高温低湿环境会加速黄花菜的干燥速率,雨天时室内外低温高湿环境会降低黄花菜的干燥速率,但干黄花菜的品质最佳;真空冷冻干燥技术效率最高、干黄花菜颜色较好,但能耗大,投资成本高;干燥箱烘干效率随温度的升高而提高,烘干效率由低到高依次是60、70、75、80℃,但80℃高温烘干会导致黄花菜褐色加深。综合考虑在保障黄花菜的品质、降低预算的情况下,推荐75℃干燥箱烘干为黄花菜的适宜烘干工艺。

The fresh daylily was dried by airing, drying through drying oven(60, 70, 75, 80 ℃) and vacuum freezedrying(75 ℃), respectively, then the qualities changes of daylily during drying processes were analyzed, the water contents, dry base moisture contents and drying rates were calculated, and the corresponding curves were drawn for comparing the drying effects. Results showed that the drying processes depended on the weather conditions. Under sunny conditions, high temperature and low humidity in indoor and outdoor environments accelerated the drying rates of daylily, while under rainy conditions, low temperature and high humidity in indoor and outdoor environments reduced the drying rates of daylily, but the dry qualities was the best. Vacuum freeze-drying technology presented the highest efficiency and better color of dried daylily, but the energy consumption and investment cost were high.Drying efficiency of drying oven was raised with the increase of temperatures, the drying efficiency from low to high order was 60, 70, 75, 80 ℃, but high temperature drying(80 ℃) would lead to the brown deepening of daylily.Comprehensive consideration on the conditions of ensuring the daylily qualities and budget reduction, the drying condition through drying oven at 75 ℃ was recommended as the suitable drying process of daylily.