Kinetics of Protein Degradation and Physical Changes in Thermally Processed Atlantic Salmon (Salmo salar)

Abstract

Protein denaturation is the main reason for physicochemical changes in muscle foods during thermal processing. The purpose of this study was to understand the kinetics of quality degradation and protein denaturation of Atlantic salmon (Salmo salar) during thermal pasteurization. Findings indicate that cook loss, area shrinkage, and protein denaturation parameters (both dielectric loss and differential scanning calorimetry (DSC) studies) were best fitted to a first-order reaction. In addition, color parameters followed zero-order kinetics. Fourier transform infrared spectroscopy (FTIR) results showed that increasing heating time and temperature reduced the α-helix peak, indicating protein denaturation. At the same time, the β-sheet peak intensity increased, which is related to protein aggregation. Correlation loading plots from FTIR spectra showed that protein denaturation was dominant below 75 °C. Above this transition temperature, protein denaturation occurred rapidly and protein aggregation became more obvious. The dielectric properties in cooked salmon at different times and temperature increased with increasing heating time and temperature, while penetration depth decreased significantly (P < 0.05). The kinetics of protein denaturation from DSC showed that the activation energy of 300.6 kJ/mol and k 0 was 1.1 × 1042 min−1. Our findings on kinetic data from protein denaturation and physical changes may be used to improve the processing schedule in the production of safe, high-quality pasteurized salmon.