Effects of vacuum pack onn the shelf life of live mussels (Mytilus galloprovincialis)

Italy is one of the main mussel producer Country in the EU, but this production is not matched by development of processing techniques able to maintain product quality and facilitate storage and utilization along the supply chain. Changes in consumer’s habits suggest the need for processed products with longer shelf-life also for traditional seafood like mussels. This research was aimed to compare the effect of under vacuum package (SV) with traditional plastic net (RT) on live mussel shelflife. The effect of the storage method was evaluated on chemical, physical and microbiological parameters of M. galloprovincialis kept at 3°C±0.5 for 16 days. Statistical analysis was used to compare the collected data. In a first trial, groups of 15 mussels were checked in duplicate in terms of mortality, intervalvar liquid release, edible portion water holding capacity and microbiological counts to evaluate the effect of the innovative and traditional package at day 1, 3, 6, 9, 13 and 16. Vacuum storage resulted able to extend live mussel shelf-life: mortality started earlier in RT group (day 6 of storage) relatively to the SV group (day 9 of storage). In a second trial, the effect of byssus removal was tested. Four groups of 15 mussels were daily sampled for 13 days. Mussels kept under vacuum with byssus (SVBS) exhibited lower mortality compared to RT groups or under vacuum after byssus removal (SVDB). Microbiological counts and pH values of the edible parts, although modified during storage, did not reveal significant differences between groups SVBS and SVDB. The research shows the efficacy of vacuum packaging to extend live mussel shelf-life in comparison with the traditional plastic net while preventing product contamination and body fluids loss.