草莓冷冻干燥工艺研究

Study on the Vacuum Freeze-dried Technology of Strawberry and Production Line Designing

以长丰草莓(品种为天香)为对象,对整粒草莓的真空冷冻干燥技术进行研究。以复水比为指标,考察了草莓预冻工艺和真空冷冻干燥工艺中影响产品质量的主要因素,通过正交试验对草莓的冷冻干燥工艺进行优化,确定了适合工业化生产的工艺参数。研究结果如下:试验所用草莓的共晶点为-15℃;最佳预冻条件是:在-25℃中冷冻2.5 h;真空冷冻干燥工艺可分为四个阶段:第一阶段在-25℃干燥10 h,第二阶段在-5℃干燥10 h,第三阶段在15℃干燥12 h,第四阶段在40℃干燥8h,此时工艺最佳。

Selecting Changfeng strawberry （varieties of Tianxiang） as the research object, the vacuum freeze-dried technology of total strawberries was studied. Using rehydration rate and sensory evaluation as index, the main factors in the process of pre-freezing and vacuum freeze-drying were surveyed. Finally, the process parameters suitable to industrial production were optimized through orthogonal experiments, the results were as follows： the eutectic point of this kind of strawberry was -15 ℃; the optimal pre-freezing conditions was -25 ℃ for 2.5 h; the optimal vacuum freeze-drying process was divided into four stages, the first stage was drying in -25 ℃ for 10 h, the second stage was drying in -5 ℃ for 10 h, the third stage was drying in 15 ℃ for 12 h, the forth stage was drying in 40 ℃ for 8 h.