降温速率对梨瓜细胞冻干特性的影响  

Effect of Cooling Rate on Freeze-drying Characteristics of Pear Melon Cells

作　　者：张哲[1] 郎元路 吴巧燕 张志强[1] 陈佳楠 计宏伟[1] 田津津 ZHANG Zhe;LANG Yuanlu;WU Qiaoyan;ZHANG Zhiqiang;CHEN Jianan;JI Hongwei;TIAN Jinjin(School of Mechanical Engineering,Tianjin University of Commerce,Tianjin 300134,China)

机构地区：[1]天津商业大学机械工程学院,天津300134

出　　处：《食品工业科技》2022年第19期31-42,共12页Science and Technology of Food Industry

基　　金：天津市自然科学基金(21YDTPJC00300);国家自然科学基金(12172254;11772225);天津市研究生科研创新项目(2020YJSS066;2021YJSS291);天津商业大学大学生创新训练项目(202110069059)。

摘　　要：为了探究降温速率对梨瓜细胞冻干过程中的影响,基于低温显微镜成像及真空冷冻干燥技术,对梨瓜细胞进行了不同降温速率(5、15、25、35、50℃/min)下的冻干可视化实验,分析了脱水干燥过程中的细胞形态学参数(当量直径、面积、周长、体积)以及内压在冻干过程中的变化规律,并对干燥组织的多孔物料特征参数(孔隙率)进行了研究。结果表明:冻结温度随着降温速率的增长整体呈逐渐降低的趋势;冻干过程中,降温速率为25℃/min时,细胞形态学参数和内压变化最小,其中,细胞形态学参数变化率与内压均随降温速率的增大呈先减小再缓慢增加的趋势;过高和过低的降温速率下,梨瓜细胞形态与内压变化较大,不利于梨瓜的冻干处理;当降温速率大于5℃/min时,孔隙率较大且受降温速率的影响较小,只在一定范围内发生微小波动;梨瓜的最佳降温速率为25℃/min,该降温速率下的细胞形态及溶质损害最小。In order to explore the effect of cooling rate on the freeze-drying process of pear melon cells, the pear melon cells were subjected to different cooling rates(5, 15, 25, 35, 50 °C/min) based on cryomicroscopy imaging technology and vacuum freeze-drying technology. The freeze-drying visualization experiment was carried out, and the changes of cell morphological parameters(equivalent diameter, area, circumference, volume) and internal pressure during the freeze-drying process were analyzed. The characteristic parameters of porous materials(porosity) of dry tissue were studied. The results showed that: The freezing temperature generally decreased with the increase of the cooling rate. During the freeze-drying process, when the cooling rate was 25 °C/min, the changes of cell morphological parameters and internal pressure were the smallest. With the increase of cooling rate, the change rate of cell morphological parameters and internal pressure first decreased and then slowly increased. The cell morphology and internal pressure of pear melons changed greatly under too high and too low cooling rates, which was not conducive to the freeze-drying of pear melons. When the cooling rate was greater than 5 ℃/min, the porosity was larger and less affected by the cooling rate, and only small fluctuations occured within a certain range. The optimal cooling rate of pear melon was 25 ℃/min, and the cell morphology and solute damage were the least at this cooling rate.

关 键 词：真空冷冻干燥 降温速率 冰晶生长 细胞形态学 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]