Identification of potential freshness indicator of Atlantic salmon based on iTRAQ proteomic analysis

Freshness is a primary indicator of fish quality, which is influenced mainly by protein degradation during refrigerated storage as manifested by changes in protein composition. However, the changes in protein composition of Atlantic salmon during refrigerated storage and its relationship with the salmon freshness remain unclear. Proteomics based on isobaric tags for relative and absolute quantitation were used to study protein changes in Atlantic salmon stored at 4 ℃. A total of 42 differentially abundance proteins (DAPs) were identified during 20 days of refrigerated storage. 25 proteins obtained by correlation analysis between DAPs and quality indicators for Atlantic salmon were significantly correlated with salmon color, sensory properties, total number of colonies, and volatile alkaline nitrogen, which could be used as potential indicators to reflect change in salmon freshness. This findings shed light on proteome changes and the mechanisms behind the decline in Atlantic salmon quality during refrigerated storage. This study provides valuable evidence for better control and monitoring of Atlantic salmon during transportation and storage.