Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Department of Food Science and Technology, University of California Davis, Davis, CA 95618, USA.
Food Chem. 2023 Jan 15;399:133989. doi: 10.1016/j.foodchem.2022.133989. Epub 2022 Aug 24.
To characterize the involvement of microorganisms in amino acid degradation and fish quality deterioration, three major grass carp spoilage bacteria were artificially inoculated in amino acid solutions (in-vitro) and grass carp flesh (in-situ). Results showed that Pseudomonas putida largely degraded free amino acids and produced 3.78 mM/100 g ammonia in grass carp flesh, relying on its high amino acid deamination activity. Aeromonas rivipollensis produced 3-Methyl-butanol and 2-Methyl-butanol through leucine and isoleucine degradation. Shewanella putrefaciens had potent ornithine-decarboxylation activity (423.91 × 10 µg/CFU) and released 22.98 mg/kg putrescine in situ. S. putrefaciens could produce more putrescine when cooperating with P. putida through the arginine deiminase pathway. To conclude, the biochemical activities identified through in-vitro tests correlated well with quality changes in inoculated grass carp flesh. The outcomes of this study provided fundamental information on the spoilage mechanisms of freshwater fish and important guidance for the development of quality control strategies.
为了研究微生物在氨基酸降解和鱼肉品质劣变中的作用，本研究采用人工接种的方法，分别在氨基酸溶液（体外）和草鱼鱼肉（体内）中接种三种主要的草鱼腐败菌。结果表明，假单胞菌（Pseudomonas putida）主要通过高氨基酸脱氨酶活性来降解游离氨基酸，并在草鱼肌肉中产生 3.78mM/100g 氨。河流弧菌（Aeromonas rivipollensis）通过亮氨酸和异亮氨酸降解产生 3-甲基-1-丁醇和 2-甲基-1-丁醇。腐败希瓦氏菌（Shewanella putrefaciens）具有很强的鸟氨酸脱羧酶活性（423.91×10µg/CFU），并在原位释放 22.98mg/kg 腐胺。腐败希瓦氏菌通过精氨酸脱氨酶途径与假单胞菌协同作用时，可以产生更多的腐胺。总之，体外试验中鉴定的生化活性与接种草鱼肌肉的品质变化密切相关。本研究结果为淡水鱼腐败机制提供了基础信息，为质量控制策略的制定提供了重要指导。
