Skin and vacuum packaging of portioned Atlantic salmon originating from refrigerated seawater or traditional ice storage

Summary

The effect of gutted whole fish storage method after slaughter (refrigerated seawater (RSW) −1 °C, ice 0 °C) and common fish packaging methods (vacuum skin, traditional vacuum) in refrigerated storage at 4 °C were investigated. Quality parameters such as pH, drip loss, water holding capacity, colour, texture and microbial growth were analyzed. There was an overall weight gain of 0.9% and salt uptake up to 0.23% for fish stored in RSW for 4 days, followed by ice storage for 3 days. After packaging, pH and hydrogen sulphide producing bacteria in RSW stored fish were lower than iced fish. Drip loss and microbial growth increased through packaged storage, while water holding capacity decreased in all samples. Skin packaged fillets presented a higher drip loss and were lighter, less reddish and less yellowish than traditionally vacuum packaged fillets. Lightness increased, and firmness decreased throughout the experimental period, while redness and yellowness decreased after packaging. Predictive microbiology gave good agreements with the experimental values. It is concluded that storage in RSW extends the lag time of microbial growth and presents good quality traits as those from ice, and the main difference between the packaging methods was drip loss and colour.