壳聚糖对冰藏鲈鱼品质及其菌群变化的影响

Influence of Chitosan on Quality and Change in Intestinal Flora ofLateolabrax japonicus During Iced Storage

为研究壳聚糖涂膜对鲈鱼在冰藏过程中品质及其细菌菌群变化的影响,每隔3 d测定壳聚糖涂膜组(K)和对照组(C)鲈鱼样品的感官评分值、菌落总数、pH值、TVB-N值、TBA值作为品质评价指标,同时采用末端限制性酶切片段长度多态性分析(T-RFLP)技术结合细菌文库分析冰藏过程中鲈鱼肌肉的细菌群落变化情况。结果表明,K的鲈鱼细菌总数、pH值、TVB-N值、TBA值均显著低于C(P<0.05),感官分析结果表明,冰藏时K的鲈鱼货架期为18～21 d,而C的鲈鱼货架期为12～15 d;T-RFLP技术分析结果表明,冰藏0～9 d时,C、K均有3个优势末端限制性片段(T-RFs),分别为T-RF 141、456和488 bp,C在冰藏12 d时T-RF 490 bp为优势峰,冰藏18 d时C出现T-RF 555 bp,而K在冰藏15 d时也出现优势峰T-RF 490 bp,一直持续到冰藏21 d又出现了T-RF 555 bp;T-RFLP技术结合细菌文库分析结果表明,T-RF 490 bp为假单胞菌属(Pseudomonas sp.),T-RF 555 bp则是厚壁菌门的环丝菌属(Brochothrix sp.),由此推断假单胞菌属和环丝菌属是造成鲈鱼货架期缩短的优势腐败菌。本研究为鲈鱼的生物保鲜及冰藏过程中鲈鱼肌肉细菌菌相变化研究提供了理论依据。

In order to study the effect of chitosan films on the quality and microorganism community of perch（Lateolabrax japonicus） during iced storage, we measured quality evaluation index of coating group（K） and control group（C） every three days, including the sensory evaluation value, total bacteria count, pH value, TVB-N value and TBA value. At the same time, the terminal restriction fragment length polymorphism（T-RFLP）, combined with bacterial libraries, was used to analyze the microorganism community changes of perch. The results showed that the total bacterial count, pH value, TVB-N and TBA of K group were significantly（P〈0.05） lower than those of C group. Combined with the results of sensory evaluation, the shelf-life of the K group samples was to 18～21 days at iced storage, while to 12～15 days for the C group. T-RFLP profiles analysis indicated that the dominant T-RFs of K group and C group were T-RF 141 bp, 456 bp and 488 bp in 0～9 days. In C group, T-RF 490 bp became the dominant T-RF at 12 day, and new 555 bp appeared at 18 day. In K group, T-RF 490 bp appeared at 15 day and remained as dominant T-RF, and T-RF 555 bp appeared at 21 st day. T-RFLP and clone library analysis confirmed that T-RF 490 bp belonged to Pseudomonas sp., while T-RF 555 bp for Brochothrix sp.. Thus Pseudomonas sp. and Brochothrix sp. were the main specific spoilage organism to shorten shelf life of perch. This study provided theoretical basis for biological preservation of perch and the changes of bacterial community in perch meat during ice storage.