对虾冷藏过程中细菌菌相变化的研究

Study on Changes in Microbial Flora of Prawns during Storage

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。

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.