The effects of vacuum and modified atmosphere packaging on quality changes in seasoned cobia (Rachycentron canadum) sticks stored under refrigeration

Abstract The objective of this research was to compare the quality attributes of seasoned cobia sticks packed under vacuum and using modified atmosphere packaging (MAP) and stored under refrigeration, as well as to establish the most suitable gas mixtures to maintain product freshness and provide an extended shelf life. The seasoned cobia sticks were breaded with a mixture of dehydrated spices (parsley, onion, garlic, tomato and bacon), packaged under vacuum; 100% aerobic package (control, with the presence of atmosphere air); MAP1 (15% N2 + 80% CO2 + 5% O2), and MAP2 (20% N2 + 70% CO2 + 10% O2 ), and stored at 5°C for 28 days. Samples were taken every 72 hours for the microbiological analyses (total mesophilic count, total psychrotrophic count, coagulase positive Staphylococcus, Salmonella sp., and thermotolerant Coliforms at 45°C) and physicochemical analyses (pH, the nitrogen from the total volatile bases, and trimethylamine), all carried out in triplicate. The results showed that the seasoned cobia sticks remained safe and with good microbiological, physical and chemical quality for a longer period when packed in a modified atmosphere. MAP1 (15% N2 + 80% CO2 + 5% O2) was the system showing the best performance in the maintenance of quality and freshness, demonstrating the feasibility of ensuring quality and a longer shelf life (28 days) at 5°C.