Title: Shelf life of red fish stored in ice and MAP (modified atmosphere packaging). Development of the Quality Index Method for MAP red fish

The objectives of the project were to study the shelf life of red fish stored in ice and in modified atmosphere (MA). In addition, to analyse and define the parameters to be used in the development of a Quality Index Method (QIM) scheme for red fish stored in modified atmosphere.

Samples of iced red fish (Sebastes marinus, S. mentella) caught south of Iceland were stored in ice and in a modified atmosphere (60% CO2: 40%N2) two days after capture and investigated with sensory analysis, chemical measurements and microbial counts, during 4 sampling days.

Differences in total volatile bases (TVB), trimethylamine (TMA) and trimethylamine oxide (TMAO) values between red fish stored in ice and modified atmosphere were not significant. The pH of MA samples remained lower than in ice samples. The Total Viable Counts and Pseudomonas in ice samples were much higher than in MA samples.

Significant differences in sensory changes during storage of ice and MA samples were found. The colour of eyes of fish stored in MA had higher scores than iced samples (changes from black to grey colour), and skin colour of fish stored in MA was more yellow.

The iced fish samples reached the limit of acceptance in day 19 according to sensory evaluation of cooked fish, whereas fish stored in MA reaches that limit in day 21. MA gave a 2 days shelf life extension of red fish.

The QIM scheme for red fish stored in ice is not suitable for red fish stored in modified atmosphere. A slightly modified QIM scheme specific for red fish stored in MA is needed.