Effect of high‐pressure treatment and refrigerated storage on the amino acid profile, color, and texture of hammour ( Epinephelus coioides ) fillets

Abstract

The objective of this study was to assess the quality parameters of hammour (Epinephelus coioides) fillets subjected to a high-pressure (HP) treatment at 375 MPa for 20 min followed by refrigerated storage for 30 days. The optimum pressure/time was selected based on the complete inactivation of Listeria monocytogenes. Treated samples were analyzed by amino acid profile, visual color, microstructure, and texture profile analysis. Lysine and glycine were the predominating essential and non-essential amino acids in hammour fillets. The total amino acids did not change by the HP-treatment, whereas the free amino acids decreased markedly from 4.35 to 2.43 mmol/g. The color of fillets changed significantly with the pressurization and storage in particular, a* and b* values. Hardness, compressibility, and adhesiveness increased after the HP-treatment. FTIR results indicated a shift in the amide II band after the HP-treatment and storage due to high-pressure-assisted protein denaturation. A porous structure was identified in the HP-treated microstructure of the fillet. The results indicated that HP-treatment could be successfully applied to hammour fillets for reduction of microbial growth with minor changes in quality. Industrial relevance In recent days, the acceptability of high-pressure (HP) processing in the seafood industries is growing significantly. Hammour has a huge demand in the Middle Eastern countries for its exotic flavor and taste. An optimum pressure/time combination could maintain the desired flavor and safety of the fish fillets. Storage of high-pressure-treated fillets, however, showed a decrease of the PUFA content significantly that needs to be further addressed. The obtained results could help the fish processing and service industries to boost the economy by providing pressurized hammour fillets. Novelty impact statement High-pressure treatment retained the total amino acid contents and texture of hammour fish fillets. Retention of visual color/pigment remains the challenge of the process.