响应面法优化青椒微波-真空冷冻联合干燥工艺及品质分析

该研究采用微波-真空冷冻联合干燥方式对青椒进行干制，研究微波功率、中间转换点含水率及真空冷冻干燥时间对青椒干燥产品维生素C含量、感官评分、复水比及a*的影响。通过单因素试验和响应面试验优化微波-真空冷冻联合干燥工艺，并对青椒联合干燥产品的营养成分、风味进行了比较分析。最后研究了微波-真空冷冻联合干燥、微波干燥、真空冷冻干燥对青椒干燥品质的影响。结果表明，联合干燥的最佳工艺条件为微波功率381.17 W，中间转换点含水率61.81%，真空冷冻干燥时间12.04 h。3种青椒联合干燥产品在营养成分和风味上分别具有一定差异性。微波-真空冷冻联合干燥和真空冷冻干燥的青椒产品在质构、青椒组织微观结构、部分理化指标方面均优于微波干燥的青椒产品。

Process Optimization of Microwave-vacuum Freezing Combined Drying of Green Pepper by Response Surface Methodology and Its Quality Analysis

In this study, green pepper was dried by the microwave-vacuum freezing combined drying method. The effects of microwave power, moisture content at the intermediate conversion point and vacuum freeze-drying time on the vitamin C content, sensory score, rehydration ratio and a* of the dried green pepper were studied. The microwave-vacuum freezing combined drying process was optimized by the single factor experiments and response surface experiments, and the nutritional components and flavor of the green pepper products via combined drying were compared and analyzed. Finally, the effects of microwave-vacuum freezing combined drying, microwave drying and vacuum freeze drying on the drying quality of green pepper were studied. The results showed that the optimal process conditions for combined drying were microwave power 381.17 W, moisture content at the intermediate conversion point 61.81%, vacuum freeze drying time 12.04 h. The three kinds of combined drying green pepper products showed certain differences in nutritional contents and flavors. The green pepper products subjected to microwave-vacuum freezing combined drying and vacuum freeze drying were superior to those subjected to microwave drying in terms of texture, microstructure, and certain physicochemical indexes.