Hyperbaric cold storage: Pressure as an effective tool for extending the shelf-life of refrigerated mackerel (Scomber scombrus, L.)

The efficacy of hyperbaric cold storage for preserving lean fish has been recently demonstrated but, to the best of our knowledge, no data exist for fatty fish. To evaluate the effect of hyperbaric cold storage on the shelf-life and quality of fatty fish, we stored Atlantic mackerel fillets at 5 degrees C, both at atmospheric pressure and at 50 MPa. After 12 days of hyperbaric storage, no microbial growth was observed. Thus, most counts were similar or slightly lower than those of control samples at day 0, while H2S-producing organisms and sulphite-reducing bacteria reduced under the detection limits. Moreover, no significant lipid degradation was observed. By contrast, increased microbial counts and significant lipid hydrolysis were detected in the samples stored at atmospheric pressure. Moreover, even though the protein profile was significantly altered during hyperbaric storage, most fish-quality indicators (pH, TVB-N, drip loss, water-holding capacity, and firmness after cooking) were better preserved in the mackerel samples stored at 50 MPa. These results clearly prove that hyperbaric cold storage was more efficient than conventional refrigeration for the preservation of Atlantic mackerel fillets. Industrial relevance: Long-term preservation of fatty fish is a challenge for the seafood industry mainly due to lipid degradation that can rapidly reduce fish quality. If effective against lipid degradation, hyperbaric cold storage could be an interesting technology to preserve fish and fish products. The increased cost resulting from hyperbaric storage should be overcome by an extended shelf-life of a high-quality product.