壳聚糖对带鱼冷藏期间微生物多样性的影响研究

Effects of Chitosan on Microbial Diversity of Cutlassfish(Trichiurus haumela) During Chilled Storage

本文研究了壳聚糖对冷藏（4±1℃）带鱼贮藏期间微生物多样性的影响，分别选取0、2、4、6、8、10、12d，以感官评分、pH值、菌落总数为测定指标，同时进行微生物分离纯化，提取细菌DNA与PCR扩增，将扩增产物测序。结果表明，10．0g／L的壳聚糖溶液能明显延缓带鱼鲜度下降，抑制细菌增长，冷藏货架期较对照组延长了4—5d。对照组样品在腐败末期（10d）的菌相组成是：草莓假单胞菌（Pseudomormsfragi）（29．5％），荧光假单胞菌（Pseudomonas fiuorecens）（33．4％），腐败希瓦氏菌（Shewane／／aputrefac／ens）（32．％），松鼠葡萄球菌（Staphylococcussciuri）（5．1％）；处理组（12d）有：草莓假单胞菌（Pseudomonas fragi）（38．2％），荧光假单胞菌（Pseudomonas fluorescns）（30．1％），腐败希瓦氏菌（Shewanella putrefaciens）（29．0％），热死环丝菌（Brocho thrixthermosphacta）（2．7％）。经壳聚糖处理后的带鱼样品，在其贮藏期间，使腐生葡萄球菌（Staphylococcussapro-phrticus），松鼠葡萄球菌（Staphylococcus sciuri）与嗜冷杆菌（Psychrobacter spp．）的生长受到抑制。草莓假单胞菌（Pseudomonasfra#）、荧光假单胞菌（Pseudomonas fluorescens）与腐败希瓦氏菌（Shewanella putrefaciens）为优势腐败菌。

In this paper,the microbial diversity changes of cutlaasfish （Trichiurus haume/a） coated with chitosan during chilled storage （4 ± 1 ℃） were investigated. The sensory evaluation, pH value and total viable counts （TVC） were measured in day 0,2,4,6,8,10,12. The strains of samples from different days were separated, purified, DNA extraction and PCR amplification. The results showed that 10.0 g/L of chitosan significantly increased the fresh duration of cutlass- fish and inhibited the growth of microorganism. The shelf-life of cutlassfish was prolonged for almost 4-5 days. At the end of spoilage period,the main changes of bacteria in controlled （ 10 d） were Pseudomonasfiagi 29.5% ,Pseudomonasflu- orescens 33.4% ,Shewanella putrefaciens 32.0% ,Staphylococcus sciuri 5.1% ,and the bacteria of samples （12 d） with chitosan were Pseudomonas fiagi 38.2% ,Pseudomonas fluorescens 30.1% ,Shewanella putrefaciens 29.0% ,Brochothrix thermosphacta 2.7%. Chitesan can inhibit the growth of Staphylococcus saprophyticus,Staphylococcus sciuri and Psy- chrobacter spp,the dominant species were Pseudomonas fiagi, Pseudomonus fluorescens and Shewanella putrefaciens.