Relationship between physicochemical properties, non-volatile substances, and microbial diversity during the processing of dry-cured Spanish mackerel

Abstract

To meet the demand of consumers for high-quality dry-cured fish. This study investigates the relationship between microbial diversity and the changes in physicochemical properties and non-volatile flavor compounds of dry-cured Spanish mackerel (DCSM) throughout the curing process. Our findings demonstrate that moisture content significantly decreased during curing, while NaCl generally increased. The nitrite level of 1.52 mg/kg, meeting national safety standards. Additionally, there was a significant increase in hardness and chewiness. The synergistic effect of glutamic acid (Glu), alanine (Ala), and histidine (His) with inosine monophosphate (IMP), adenosine monophosphate (AMP) and guanosine monophosphate (GMP) enhanced the umami taste. Proteobacteria and Photobacteria are the main microorganisms of DCSM at the phylum and genus levels. Proteobacteria and Photobacteria are the main microorganisms of DCSM at the phylum and genus levels. Photobacterium, Moritella, and Pseudomonas were positively correlated with AMP, GMP, Ala, and Glu. And negatively correlated with nitrite and TBARS. These findings suggest that specific microorganisms positively influence the quality of DCSM through their metabolic activities. This research enhances our understanding of flavor formation mechanisms and provides critical insights for optimizing DCSM processing and quality control.

Keywords: Dry-cured Spanish mackerel; Free amino acids; Microbial diversity; Nitrite content; Pearson correlation.