冷却速率对洋葱内表皮细胞结构的影响  

Effect of Cooling Rate on the Structure of Onion Epidermal Cells

作　　者：王雅博[1] 诸凯[1] 代宝民 王金山 刘圣春[1] 谢艳琦 Wang Yabo;Zhu Kai;Dai Baomin;Wang Jinshan;Liu Shengchun;Xie Yanqi(Tianjin Key Laboratory of Refrigeration Technology,Tianjin University of Commerce,Tianjin,300314,China)

机构地区：[1]天津商业大学天津市制冷技术重点实验室,天津300134

出　　处：《制冷学报》2018年第6期129-134,共6页Journal of Refrigeration

基　　金：国家自然科学基金(51676139)资助项目;天津市自然科学基金项目(16JCQNJC14000)~~

摘　　要：本文通过控制冷却速率观测了洋葱内表皮细胞结构的动态变化,根据透光强度定量分析了胞内冰晶对细胞结构的影响,对内压与体积的变化关系进行讨论,并研究了冷却速率对过冷度、结晶时间及细胞形变的影响。结果表明:冷却速率越慢,细胞内产生的冰晶数量越少,体积越大,对细胞造成的机械损伤越大。冷却速率从2℃/min升至90℃/min时,细胞的平均灰度值下降了37.2%;体积随内压的增大而减小,内压变化越大,细胞结构的变化越显著,在2℃/min时,冷却-复温后,内压增大了0.388×10^(-2) Pa,体积减小了2.264×10^(-13) m^3。冷却速率对细胞的过冷度、结晶时间及变形量影响显著,在90℃/min时,冷却-复温后相对体积变化为1.24%。Abstract The dynamic variation characteristics of an onion epidermal cell structure under different cooling rates and the impact of intra- cellular ice crystal on the cell structure were investigated experimentally. The internal relations between pressure and volume were also discussed. The relationship between the supercooling degree, Crystallization time, and cell deformation was analyzed. Additionally, the structural teature of the cells after rewanning was shown. The results indicate that the number of intracellular ice crystals tonned is de- creased and their size is increased with the decrease in the cooling rate, which result in more mechanical damage of cell. The average gray scale decreases by 27.5% from 2 ℃/min to 15 ℃/min and 37.5% from 2 ℃/rain to 90 ℃/min. The volume of the cell decreases with increases in the internal pressure, and the cell collapses at a critical internal pressure. When the cooling rate is 2 ℃/min, the internal pressure is increased by 0. 388 × 10-2 Pa and the volume is decreased by 2. 264 × 10^-13 m3 tollowing the fl＇eezing-thawing process. The diiterences in the cooling rates have influence on the supercooling degree, crystallization time, and cell deformation. When the cooling rate is 90 ℃/min, relative volume change in the cell is 1.24% tollowing the freezing-thawing process.

关 键 词：冻结食品 胞内冰 内压 过冷度 冻结点 

分 类 号：TB611[一般工业技术—制冷工程] TS255.3[轻工技术与工程—农产品加工及贮藏工程]