快速评估青菜冷处理的临界点温度  

Rapid Assessment of Critical Point Temperature of Pak Choy by Refrigerating Treatment

作　　者：顾双[1] 王向阳[1] Gu Shuang;Wang Xiangyang(College of Food and Biological Engineering,Zhejiang Gongshang University,Hangzhou 310018)

机构地区：[1]浙江工商大学食品与生物工程学院

出　　处：《中国食品学报》2019年第10期190-196,共7页Journal of Chinese Institute Of Food Science and Technology

基　　金：浙江省食品科学与工程“重中之重”一级学科基金项目(JYTSP20141101);浙江省公益技术研究项目(LGN18C200014)

摘　　要：目的:快速找到青菜冷处理的临界点温度。方法:使用叶绿素荧光仪和离子选择性电极测定不同温度冷水处理的青菜。结果:青菜叶片用冷水处理1 min,在-4℃检出低温伤害,显示处理时间不够。冷水处理青菜10 min,可以判断冷害温度,而不足以激发显著的冷激反应。在0℃时,ETR和qP下降极显著,Y(NO)显著上升。在2℃时,所有荧光参数正常,属于安全温度。处理30 min时,2℃处理的NPQ和qN显著上升,有明显的冷激反应。0℃处理30 min后K^+溶出极显著上升(P<0.01),说明细胞膜渗漏加剧,青菜在0℃下贮藏可能有冷害。0~2℃处理Ca^2+溶出显著上升,说明已引起细胞壁的变化。Na^+溶出随温度下降而下降,0℃处理Na^+的溶出最少。结论:ETR和K+溶出可作为冷害指标,NPQ和qN可作为冷激温度和时间的指标。0℃冷水处理10 min或30 min均可以检出低温伤害,青菜在0℃下长期贮藏可能有冷害,2℃处理30 min有冷激反应,在该温度可以安全贮藏。1℃是两者的临界点。Objective:In order to find rapid assessment of critical point temperature for cold shock treatment and low temperature storage.Method:After pak choy(Brassica rapa var chinensis)dipped in different temperatures of cold water,the leaves were measured by chlorophyll fluorescence analyzer,and the osmosis and diffusion amount of potassium(K+),calcium(Ca2+)and sodium(Na+)were determined by ion electrodes.Result:Pak choy was dipped in cold(or salt)water for 1 min,all fluorescence data did not significantly change until treatment temperature dropped to-4℃.Obviously,the dipping time of 1 min for judging chilling injury temperature was not enough.When pak choys were treated with 0℃water for 10 min,all parameters had significantly changed.Especially,ETR and qP had extremely significant decrease,while Y(NO)was significant increase.When pak choys were treated with 2℃water for 10 min,all fluorescence data did not show significantly change,so 2℃was identified as a non-hazardous temperature,and treatment for 10 min was enough time for judging chilling injury temperature,but not enough for judging cold shock response temperature.When leaves treated by 2℃water for 30 min,Stern-Volmer type NPQ and qN were significantly increased,and obvious cold shock response were observed.The diffusion and osmosis content of K+treated with 0℃water for 30 min were extremely significantly higher than that of 4℃(P<0.01),which showed that cell membrane leakage was exacerbated,and pak choy might suffered chilling injury at 0℃.The diffusion amounts of Ca2+from pak choy treated with 0-2℃was exceeded than that of 4℃,which meant low temperature might induce the changes of the calcium binding capacity of cell walls.The diffusion of Na+decreased with the dropping of temperature,and Na+of 0℃treatment was significantly lower than that of 4℃(P<0.05).Conclusion:ETR data and diffusion and osmosis content of K+can be used as parameters for judging chilly injury temperature,NPQ and qN can be used as parameters for judging the temperature an

关 键 词：青菜 叶绿素荧光参数 低温伤害 冷激处理 离子电极 

分 类 号：TS2[轻工技术与工程—食品科学与工程]