Quality of fresh saithe (Pollachius virens) in modified atmosphere packages as affected by the gas composition

Abstract

The experimental design was set up to study the effect of different modified atmospheres (CO2 (67 or 33%) balanced with either O2 or N2) on autolytic- and microbiological deterioration of chilled saithe (Pollachius virens). As controls, vacuum packaged saithe was used. The results showed a positive effect of gas mixtures containing O2 on physiochemical and microbial product quality. Discriminating factors were; lower psychrotrophic count, slower breakdown of ATP, lower contents of certain biogenic amines (e.g. cadaverine) and reduced drip loss during storage. A high CO2 concentration (67%) in the packaging atmosphere was moreover found to inhibit microbial proliferation. Vacuum-packaged saithe stand out negatively with highest DL and reduced sensory shelf life and physiochemical and microbial quality. It was moreover found that increased drip loss, and higher contents of hypoxanthine and cadaverine in the muscle tissue was related to the microbiological ecology (i.e. increased growth of Shewanella spp. and Photobacterium spp.).