胡萝卜冷冻干燥过程的优化及最佳工艺条件的确立

Establishment for the Optimum Technological Conditions and the Optimized Process for Carrot Freeze-Drying

对胡萝卜进行了冷冻干燥实验,确定了胡萝卜条冻干工艺条件,计算了冻结终点温度、冻结时间、物料厚度,建立了胡萝卜条冻干的传热传质模型,由模型计算出理论干燥时间,并与实验值进行了比较.探讨了冻结速率、升华温度、干燥室及捕水器温度、压强对干燥时间的影响.胡萝卜条冷冻干燥的适宜工艺参数为冻结时间1 h,物料厚度15 mm,干燥室真空度60 Pa,捕水器压强45 Pa,温度-50^-40℃,总干燥时间5 h.

The freeze-drying experiment of carrot was studied in the paper, and obtained the freeze-drying technology for carrot piece. The terminal freezing temperature and time material thickness were calculated and the heat and mass-transfer model for carrot piece was established, and the academic drying time was calculated through the model, and the comparison between calculation and experiment value was discussed. The influence of freezing rate, sublimation temperature, the temperature and pressure of drying room and water catching machine on the freeze drying process was discussed. The parameters of freeze-drying technology for carrot piece are that the freeze time is 1 h, material thickness is 15mm, pressure of drying room is 60 Pa, temperature and pressure of catching water machines is -50--40℃ and 45 Pa ,the total freeze-drying time is 5 h.