Quality Changes on Cod Fish (Gadus morhua) during Desalting Process and Subsequent High-Pressure Pasteurization

Abstract

During the desalting of salted cod, significant textural, histological, and biochemical changes occur. Understanding these changes is crucial for enhancing the preservation and extending the shelf life of desalted cod. This study aimed to investigate the physicochemical quality parameters and enzymatic activities during the desalting process of cod (16 h at 4 and 20 °C) and to extend the shelf life of desalted cod through high-pressure processing (HPP) at 400 and 550 MPa for 5 min. During desalting, a correlation was noted between the pH and trimethylamine content in samples desalted at 20 °C, with both parameters increasing in the initial 4 h and stabilizing thereafter. The soluble protein in cod muscle decreased over desalting time, as it dissolved into the desalting water. Enzymatic activity showed a decline in cathepsins (B and D) and acid phosphatase throughout desalting, whereas lipase activity increased, particularly at 20 °C. HPP effectively extended the shelf life of desalted cod by controlling endogenous microbial growth, enabling an extension to 14–21 days compared to the 7 days observed in untreated control samples. This study highlights quality changes during desalting, with lesser effects at lower temperatures. Subsequent HPP improved the microbiological quality of desalted cod during refrigerated storage.