海藻酸钠覆膜革胡子鲶鱼肉冷藏期间品质变化及与微生物多样性间相关性分析

Quality Change of Sodium Alginate-Coated Clarias gariepinus during Cold Storage and Its Correlation with Microbial Diversity

评估海藻酸钠覆膜革胡子鲶鱼肉冷藏过程中微生物及理化品质的变化,并讨论各指标间的相关性。通过高通量测序技术分析鱼肉4℃冷藏期间微生物群落结构,测定持水力、pH值、总挥发性盐基氮(total volatile base nitrogen,TVB-N)含量、硫代巴比妥酸反应物(thiobarbituric acid reactive substance,TBARs)值、生物胺含量以及感官品质的动态变化。结果表明:革胡子鲶鱼肉冷藏过程中微生物多样性逐渐降低,初始优势菌为嗜冷杆菌属、不动杆菌属和链球菌属,冷藏后期优势菌为乳球菌属、邻单胞菌属、摩根氏菌属和希瓦氏菌属;鱼肉pH值和感官品质在冷藏过程中逐渐降低,TVB-N含量、TBARs值、尸胺、腐胺、酪胺含量随冷藏时间延长逐渐上升,冷藏10 d时TVB-N含量((30.69±1.92)mg/100 g)超过食用安全上限;相关性分析表明,乳球菌属数量与鱼肉腐败指标TVB-N含量、TBARs值、组胺、酪胺含量呈极显著正相关。

The present study aimed to evaluate the dynamic changes of the microbial diversity,physicochemical and sensory qualities of sodium alginate-coated catfish(Clarias gariepinus)flesh during cold storage at 4℃and to examine the correlation between them.High-throughput sequencing technology was used to analyze the structure of microbial community.The physicochemical parameters investigated included water-holding capacity(WHC),pH,total volatile base nitrogen(TVB-N)content,thiobarbituric acid reactive substances(TBARs)value,and biogenic amine contents.The results showed that the microbial diversity diminished with storage time.At the initial stage of storage,the dominant bacteria were Psychobacterium,Acinetobacter,and Streptococcus.The dominant bacteria in the late storage period were Lactococcus,Orthomonas,Morganella,and Shewanella.The pH and sensory quality gradually decreased during cold storage.The contents of TVB-N,TBARs,cadaverine,putrescine,and tyramine gradually increased with storage time,and TVB-N content was(30.69±1.92)mg/100 g on the 10th day,exceeding the safe upper limit.Correlation analysis showed that the count of Lactococcus was positively correlated with the levels of spoilage indicators such as TVB-N content,TBARs value,histamine and tyramine contents.