对虾冷藏过程中细菌菌相变化的研究

为进一步揭示虾类的腐败机理,以养殖南美白对虾和海捕鹰爪虾为研究对象,对其贮藏过程中细菌总数(APC)和细菌菌相的变化进行了研究。结果表明,养殖南美白对虾和海捕鹰爪虾的初始细菌总数分别为4.20 Log10 CFU·g-1和3.60 Log10 CFU·g-1,南美白对虾的初始细菌总数明显高于鹰爪虾(P<0.05);贮藏过程中两种对虾细菌总数的变化情况也有所不同,但都是在第4天达到106 CFU·g-1的货架期上限水平。在南美白对虾初始菌相中,革兰氏阴性菌为优势菌,其所占比例较高的主要有Aeromonas(气单胞菌)、Pseudomonas(假单胞菌)和Enterobacteriaceae(肠杆菌),分别占26%、21%和10%;在鹰爪虾初始菌相中,也是革兰氏阴性菌占优势,其中Pseudomonas、Aeromonas和Shewanella(希瓦氏菌)比例较高,分别占28%、16%和12%。在贮藏过程中,两种对虾细菌菌相的变化情况有所不同,南美白对虾的优势腐败菌为Pseudomonas和Aeromonas,而鹰爪虾的优势腐败菌为Pseudomonas和Shewanella。

Study on Changes in Microbial Flora of Prawns during Storage

In order to reveal the spoilage mechanism of prawns,cultured Litopenaeus vannamei and wild Trachypenaeus curvirostris were selected for storage characteristic analysis.Changes in aerobic plate count(APC) and microbial flora during storage at(4±1) ℃ were determined.Results showed that the initial APC of Litopenaeus vannamei and Trachypenaeus curvirostris were 4.20 and 3.60 Log10 CFU·g-1 respectively.Changes in APC were different between the two kinds of prawns during storage.However,both reached the level of 106 CFU·g-1 at day 4.Gram-negative bacteria were dominant in the initial microbial flora of both prawns.For Litopenaeus vannamei,Aeromonas(26%),Pseudomonas(21%) and Enterobacteriaceae(10%) were dominant.For Trachypenaeus curvirostris,Pseudomonas(28%),Aeromonas(16%) and Shewanella(12%) were dominant.During storage,changes in the proportion of each genera/family were different,of which Pseudomonas and Aeromonas were dominant for Litopenaeus vannamei,while for Trachypenaeus curvirostris,the proportions of Pseudomonas and Shewanella were relatively higher.