响应面优化仙草微波间歇-热风联合干燥工艺及其对仙草凝胶品质的影响

以仙草为研究对象，采用微波间歇-热风联合干燥方式，探讨微波功率、微波间歇时间、联合干燥转换点含水率及热风干燥温度对仙草多糖提取率的影响，采用Box-Behnken进行优化，并比较不同干燥方式处理仙草对其多糖提取率及凝胶品质的影响。结果表明，通过响应面优化试验获得最优工艺为微波功率为403 W，微波间歇时间为60 s，转换点含水率为42%，热风干燥温度为74 ℃，此条件下仙草多糖提取率为13.60%。微波间歇-热风联合干燥仙草的多糖提取率高于热泵干燥仙草的多糖提取率（12.36%）和晾晒干燥仙草的多糖提取率（12.78%），干燥时间仅是后两种干燥方式的1.44%～16.67%，所制作的凝胶样品硬度（516.60±8.54）g、弹性为（0.83±0.01）和回复性(0.33±0.01)均较为适中，凝胶体内聚性（0.48±0.01）稍小，胶粘性（359.68±11.56）g和咀嚼性（285.54±13.21）g较高，凝胶样品质构特性和感官评分较优。综合比较，微波间歇-热风联合干燥更适合于仙草干燥。

Response Surface Optimization of Mesona Microwave Intermittent-Hot Air Combined Drying Process and Its Effect on Mesona Gel Quality

Taking Mesona blumes as the research object, the effects of microwave power, microwave intermittent time, drying point and drying temperature on the extraction rate of polysaccharides were studied with the microwave intermittent hot air drying method. The effects of different drying methods on the extraction rate and gel quality of Box-Behnken were studied. The results showed that the optimal process was as follows: The microwave power was 403 W, the microwave intermittent time was 60 s, the moisture content at the conversion point was 42%, the hot air drying temperature was 74 ℃, and the extraction rate of Mesona blumes polysaccharide was 13.60%. The extraction rate of polysaccharides from the microwave intermittent hot air drying was higher than the heat pump dried (12.36%) and sun- cure dried (12.78%). The drying time was only 1.44% to 16.67% of the latter two drying methods. The hardness of the gel samples (516.60±8.54) g, elasticity (0.83±0.01) and recovery (0.33±0.01) were all moderate. In the gel the cohesion (0.48±0.01) was slightly smaller, the adhesive viscosity (359.68±11.56) g and chewiness (285.54±13.21) g were higher, and the texture characteristics and sensory score of the gel samples were better. Comprehensive comparison, the microwave intermittent-hot air combined drying was more suitable for Mesona blumes drying.