Enhancement of modified atmosphere packaged farmed Atlantic halibut (Hippoglossus hippoglossus) fillet quality by soluble gas stabilization

Summary

The suitability of soluble gas stabilization (SGS) to dissolve CO2 into Atlantic halibut ( Hippoglossus hippoglossus) fillets prior to modified atmosphere packaging (MAP) were investigated. Two levels of CO2 partial pressures (200 and 400 kPa) and two levels of time (1 and 2 h) with SGS treatment was used in a factorial design, and compared to conventional MAP. Headspace gas volume (mL), headspace gas composition (%), drip loss (%), pH, microbiological characteristics, off-odor and color were assessed on the packaged fillets. Increased partial pressure and increased SGS treatment time before MAP significantly (p<0.001) increased the CO2 content in the packaged fillets and counteracted package collapse. No interaction between the time and partial pressure was found. SGS treatment significantly (p=0.038) reduced aerobic plate count (APC) and psychrotrophic count (PC). APC and PC increased significantly the tree first sampling days during storage (7, 15, and 21) and stabilized from day 21 to day 28. H2S producing bacteria and Brochothrix thermosphacta was not affected by the SGS treatment. H2S producing bacteria decreased significantly from day 7 to day 15. SGS treatment decreased the drip loss significantly (p=0.006). Color and pH were not affected by the SGS treatment. No difference in the off odor was found between the treatments. Based on off odor analysis, the shelf life of the halibut fillet in this trial exceeded 28 days.