液氮深冷速冻对三疣梭子蟹品质和微观组织结构的影响  

Effect of Cryogenic Freezing by Liquid Nitrogen on the Quality and Microstructure of Portunus trituberculatus

作　　者：鲁珺[1,2] 余海霞[2] 杨水兵[2] 吴甜甜[1] 黄佳奇 向迎春[1,2] 胡亚芹[1,2] 

机构地区：[1]浙江大学生物系统工程与食品科学学院馥莉食品研究院浙江省农产品加工技术研究重点实验室浙江省食品加工技术与装备工程中心,杭州310029 [2]浙江大学舟山海洋研究中心,浙江舟山316021

出　　处：《中国食品学报》2016年第9期87-94,共8页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家重点研发计划项目(2016YFD0400102);浙江省重大项目(2014C02017)

摘　　要：用液氮喷淋(-40℃,20 min)对舟山新鲜三疣梭子蟹冻结处理并贮藏于-18℃。作为对比,对大小相近的同批原料进行平板冻结(-20℃,6 h)以及冰柜冻结(-18℃,20 h)预处理,其它操作与液氮速冻相同。以蟹肉p H值,K值,TVBN值和TBA值为理化指标,结合SDS-PAGE电泳和光学显微观察蟹肉内部变化。结果表明:除p H值外,液氮组、平板组、冰柜组样品的各项理化指标(K值、TVBN、TBA值)在30 d内均随着时间的延长呈上升趋势,并且液氮组各项指标变化速率均显著低于平板组和冰柜组(P<0.05)。保存第30天的样品中,3组样品的K值较初始值分别增加了39.9%,45.95%,49.97%。电泳图谱显示:在30 d时,液氮组样品的肌球蛋白重链(200 ku)和肌动蛋白(45 ku)含量最高。微观结构观察发现,3种处理均导致肌原纤维不同程度的扭曲和收缩,肌原纤维间隙增大。然而,液氮组样品的肌原纤维与新鲜样品最为接近,肌纤维间隙较小,细胞完整度最好,冰晶破坏率最低。本研究结果显示液氮深冷速冻对蟹肉冻藏品质维持的效果最佳。Alive crabs （Portunus trituberculatus） harvested in Zhoushan, used as the raw materials, were pre-treat- ed by liquid nitrogen （LN2） spray freezer （-40℃, 30 rain）, followed by storage at -18 ℃ thereafter. Samples were al-so pre-treated by plate freezing （-20℃, 6 h） and frozen directly by a refrigerator （-18℃, 20 h）, which were also stored at -18 ℃. The pH value, K value, TVBN and TBA value were used as the physicochemical indicators for meat quality. SDS-PAGE electrophoresis pattern and optical microscopy of the sample meat were performed to reveal the mi- cro-structural change of the myofibrils. The result indicated that all parameters values of the liquid nitrogen pre-frozen sample, plate pre-frozen sample and refrigerator pre-frozen sample, except pH value, increased during the 30-days storage. And the change rates of pH value, K value, TVBN value and TBA value of the liquid nitrogen pre-frozen sam- ple were significantly lower（P〈0.05） than those under the other treatments. K values of the three treatments increased by 39.9 %,45.95%,49.97% during the 30-days storage, respectively. After the storage of 30 th day, eleetrophoretic pattern revealed that liquid nitrogen pre-frozen sample had the highest content of myosin heavy chain （200 ku） and actin （45 ku）. Microstrueture observation showed that the three pre-freezing methods all resulted in distortion and contraction of myofibrils at different degree. Liquid nitrogen pre-frozen sample was the most similar one to the fresh material, with ex- cellent cell integration, low space between the myofibrils and ice crystal damage. It could be concluded that the liquid nitrogen （LN2） spray method showed the best effects on the quality of Portunus tritubereulatus.

关 键 词：液氮速冻 三疣梭子蟹 K值 TVBN值 微观结构 

分 类 号：TS254.4[轻工技术与工程—水产品加工及贮藏工程]