平菇微波-真空冷冻联合干燥工艺优化及其品质分析

为得到平菇最优干燥工艺,提高其干燥制品品质,本试验利用设计专家(Design-expert)软件的Box-Benhnken design(BBD)方法设计,分别采用单因素和响应面试验方法,分析探讨微波功率、转换点含水率和真空冷冻干燥时间三个因素对产品干基含水率、干燥速率、复水比和感官得分的影响。根据试验数据得出4个指标的二次回归模型,并对其进行响应面分析,得出优化后的平菇干燥工艺,最后对最优工艺条件下的平菇干制品营养成分(蛋白质、粗脂肪和总糖含量)进行测定。平菇最佳微波-真空冷冻联合干燥工艺为:微波功率300 W、转换点含水率37%、真空冷冻干燥时间11 h,在该条件下得到的平菇干制品具有色泽良好、品质极佳、营养成分保留较高等优点,以上工艺条件可为平菇干制品的工业化生产提供一定的理论依据和指导。

Optimization of the Combined Microwave-vacuum Freezing Drying Process and Quality Analysis of Pleurotus ostreatus

This paper aims to obtain the optimal drying process of Pleurotus ostreatus as well as to improve the quality of its drying products. Based on the methods of single factor and response surface method with the Box-Benhnken design (BBD), an experiment was conducted to analyze the effect of three factors including the microwave power, moisture content of switching point and vacuum freezing time on the 4 indicators of dry basis moisture content, drying rate, rehydration ratio and sensory score of the product correspondingly. The quadratic regression models of the 4 indicators were constructed and analyzed with the response surface method according to the experimental data, and the optimal drying process of Pleurotus ostreatus was obtained, which was microwave power 300 W, conversion point moisture content 37%, vacuum freezing time 11 h. In addition, the nutrients of the dried Pleurotus ostreatus (protein, crude fat and total sugar content) were measured under the optimal process conditions. From the experiment and data analysis, it can be concluded that under the proposed optimal processing, the dried Pleurotus ostreatus products have the advantages of good color, excellent quality and high retention of nutrients, which can guide the mass-production of dried Pleurotus ostreatus under industrial conditions.