Hydrogen Inclusion in Modified Atmosphere Extends the Shelf Life of Chilled Rainbow Trout Fillets

Different gas formulations with inclusion of hydrogen were evaluated for extension of shelf life of chilled rainbow trout. A control and four treatment samples were as follows: Control (air), MAP1 (50% CO2 / 50% N2), MAP2 (60% CO2 / 40% N2), RAP1 (50% CO2 / 46% N2 / 4% H2) and RAP2 (60% CO2 / 36% N2 / 4% H2). Samples were stored at +2±1°C for 15 days and periodically analyzed for changes in their quality. TBARS exceeded consumable limits in control after 5 days while treatment samples were under the limit during storage. Consumable limits for TVB-N were exceeded after 7 days in control while treatment samples remained below the limit. The modified atmosphere was significantly effective in retarding protein degradation although a modest difference was observed due to hydrogen inclusion. Gradually increased microbial counts also confirmed quality loss in control while a rather limited change was observed under a modified atmosphere. Microbial loads of treated samples were under consumable limits until the 10th day, while control reached to limits by just the 3rd day. The incorporation of molecular hydrogen in a modified atmosphere may bring benefits to the seafood industry although further research is needed.