超声波强化真空冷冻干燥酸奶中水分蒸发的研究  

Study on Water Evaporation of Ultrasonic Vacuum Freeze Drying Yogurt

作　　者：杨菊芳[1] 周正[1] 吴昊[1] 查梦吟 陈存社[1] 

机构地区：[1]北京工商大学食品添加剂与配料北京高校工程研究中心/北京市食品风味化学重点实验室,北京100048

出　　处：《食品科学技术学报》2014年第1期53-58,共6页Journal of Food Science and Technology

基　　金：北京市自然科学基金资助项目(KZ20110011013)

摘　　要：结合超声波和真空冷冻干燥的优点,对酸奶进行干燥.与真空冷冻干燥相比,在不同超声作用时间、超声波功率和脉冲的条件下,检测酸奶干燥过程中水分损失率、干燥总时间,建立相应条件下的干燥动力学模型.结果表明:超声波干燥显著的提高了物料在较低气流速度和低温下的水分扩散,有效的缩短了干燥总时间.干燥酸奶的最佳条件为超声波功率55%(总功率为900 W)、超声脉冲5∶3、超声波作用时间1.5 h,此时干燥时间在同等条件下最短,比对照组平均缩短了20.58 h.干燥的数学模型符合指数方程Wt=W0e-Kt.In this study, ultrasonic and vacuum freeze drying were combined to dry yogurt. Compared with the vacuum freeze drying, the effects of ultrasonic time, power, and pulse on water evaporation and drying time of yogurt were determined. Meanwhile, the drying kinetics model was established. The re- sults showed that the ultrasonic synergistic vacuum freeze drying, significantly improving moisture diffu- sion of the material under the conditions of the low air velocity and low temperature, could shorten the to- tal drying time. The optimal drying conditions were ultrasonic power 495 W （55%） , ultrasonic pulse 5： 3, and ultrasonic time 1.5 h. Compared with the control group, the total drying time under the optimalconditions decreased 20.58 h. Moreover, the drying kinetics model was Wt=W0e-kt.

关 键 词：超声波 真空冷冻干燥 酸奶 蒸发数学模型 

分 类 号：TS205.1[轻工技术与工程—食品科学]