摘要
采用-60、-90、-120℃液氮冻结雷竹笋至中心温度-18℃,或-90℃液氮冻结雷竹笋至中心温度-6、-12、-18℃,真空包装后置于-18℃冰柜中冻藏24周。通过测定雷竹笋的苯丙氨酸解氨酶(L-phenylalanine ammonialyase,PAL)和过氧化物酶(peroxidase,POD)活性、总酚含量、相对电导率和水分状态,观察冰晶结构和细胞形貌,分析液氮冻结对冻藏雷竹笋生理生化特性的影响。结果显示,随着冻藏时间的延长,6组雷竹笋的PAL和POD活性、总酚含量、细胞自由水峰面积均显著下降(P<0.05),相对电导率显著上升(P<0.05);冰晶和细胞发生不同程度的变形、破损。冻结温度越低导致冰晶越小,PAL、POD活性和相对电导率越低,总酚含量越高,雷竹笋细胞形态保持越好,但是-90℃与-120℃冻结雷竹笋的生理生化特性差异不显著(P>0.05)。-6℃雷竹笋的PAL、POD活性和相对电导率均高于-12、-18℃组;-6℃雷竹笋的冰晶大于-12℃和-18℃组,细胞破坏程度重于-12℃和-18℃处理组,-12℃和-18℃雷竹笋之间的差异不显著。综合各方面考量,冻结温度-90℃、冻结至中心温度-12℃为冻藏雷竹笋较佳的液氮冻结条件。
Phyllostachys praecox shoots were frozen using liquid nitrogen at–60,–90 or–120℃to an internal temperature of–18℃,or frozen at–90℃to an internal temperature of–6,–12 or–18℃,vacuum-packed and stored in a freezer at–18℃for 24 weeks.In order to analyze the effect of liquid nitrogen freezing on physiological and biochemical characteristics of P.praecox shoots during frozen storage,L-phenylalanine ammonialyase(PAL)and peroxidase(POD)activities,total phenolic content,relative electrical conductivity,and water state were measured and ice crystal structure and cell morphology were observed.The results showed that with increasing freezing time,the PAL and POD activities,total phenolic content,and peak area of free water in all six groups decreased significantly(P<0.05),while the relative electrical conductivity increased significantly(P<0.05),with the ice crystals and cells being deformed and damaged to varying degrees.Lower freezing temperature led to smaller ice crystals,lower PAL and POD activities and relative electrical conductivity,higher total phenolic content,and better maintenance of cell morphology,but there was no significant difference in physiological and biochemical properties between P.praecox shoots frozen at–90 and–120℃(P>0.05).The PAL and POD activities and relative conductivity of P.praecox shoots frozen at–6℃were higher than those frozen at–12 and–18℃,and the size of ice crystals was smaller and the degree of cell damage was greater in P.praecox shoots frozen at–6℃than at–12 and–18℃.The difference between P.praecox shoots frozen at–12 and–18℃was not significant(P>0.05).Collectively,these findings indicated that the most suitable liquid nitrogen freezing conditions of P.praecox shoots are-90 and-12℃for freezing and internal temperature,respectively.
作者
廖锦晗
陈季旺
徐丽敏
路洪艳
王柳清
焦楚壹
LIAO Jinhan;CHEN Jiwang;XU Limin;LU Hongyan;WANG Liuqing;JIAO Chuyi(School of Food Science and Engineering,Wuhan Polytechnic University,Wuhan 430023,China;Hubei Key Laboratory for Processing and Transformation of Agricultural Products(Wuhan Polytechnic University),Wuhan 430023,China;Hubei Heyuan Gas Co.Ltd.,Yichang 443000,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2024年第13期247-255,共9页
Food Science
基金
湖北省自然科学基金重点项目(2010CBB02601)。
关键词
雷竹笋
液氮
冻结温度
中心温度
生理生化特性
Phyllostachys praecox shoots
liquid nitrogen
freezing temperature
internal temperature
physiological and biochemical characteristics