Combined Treatments of High Hydrostatic Pressure and CO in Coho Salmon (): Effects on Enzyme Inactivation, Physicochemical Properties, and Microbial Shelf Life.

This study focused on applying different high hydrostatic pressure + carbon dioxide (HHP + CO) processing conditions on refrigerated (4 °C, 25 days) farmed coho salmon () to inactivate endogenous enzymes (protease, lipase, collagenase), physicochemical properties (texture, color, lipid oxidation), and microbial shelf life. Salmon fillets were subjected to combined HHP (150 MPa/5 min) and CO (50%, 70%, 100%). Protease and lipase inactivation was achieved with combined HHP + CO treatments in which lipase activity remained low as opposed to protease activity during storage. Collagenase activity decreased approximately 90% during storage when applying HHP + CO. Combined treatments limited the increase in spoilage indicators, such as total volatile amines and trimethylamine. The 150 MPa + 100% CO treatment was the most effective at maintaining hardness after 10 days of storage. Combined treatments limited HHP-induced color change and reduced the extent of changes caused by storage compared with the untreated sample. Microbial shelf life was extended by the CO content and not by the HHP treatments; this result was related to an increased lag phase and decreased growth rate. It can be concluded that combining HHP and CO could be an effective method of inactivating endogenous enzymes and extend salmon shelf life.