The impacts of salt with Chinese liquor on the inhibition of microbial spoilage and quality attributes of grass carp ( Ctenopharyngodon idellus ) fillets stored at 4°C

In order to clarify the action of a seasoning mixture of salt and Chinese liquor in maintaining the hygienic and quality characteristics of refrigerated grass carp, the changes in physicochemical properties, biogenic amines, and microbial growth in grass carp fillets during storage at 4°C for 30 days were investigated. Results showed that fillets lightly salted with Chinese liquor had lower values of total volatile basic nitrogen, drip loss, biogenic amines contents, and higher hardness as well as stable pH during storage, compared to the untreated or individual salted groups. The increase in total viable counts and total psychrophile counts were significantly inhibited by combined adding salt and Chinese liquor. Additionally, Illumina sequencing analysis showed Enterobacteriaceae and Carnobacteriaceae were the major spoilage bacteria species in untreated samples at the end of storage, but they were highly inhibited by adding salt and Chinese liquor. Practical applications Refrigerated storage can better maintain the fresh quality of fish because it is stored under nonfrozen conditions, but the shelf life is limited due to the action of microorganisms and endogenous enzymes. Food seasoning ingredients have the characteristics of high safety, low cost, and convenient application. The combination of salt with other ingredients in fish curing to develop low-salt preservation techniques has attached increasing interest. The present study showed that curing of grass carp using salt combined with Chinese liquor can largely delay chemical changes, lower the accumulation of putrescine and cadaverine, and inhibit the growth of spoilage microorganisms in refrigerated fish fillets compared to the untreated group. This study provided a promising cost-efficient and simple preservation technique of fish.