Quality evaluation of Red Tilapia (Oreochromis sp.) fillets refrigerated and packed under modified atmosphere using a CO2 emitter
Fish has been gaining space on the consumer's table, due to its nutritional quality and favorable characteristics for maintaining the population's health. However, when not handled properly, it reduces its useful life. The use of a modified atmosphere packaging (EAM) for fish fillets, becomes an alternative to avoid product contact with external deteriorating agents. In addition, the inclusion of a CO2 emitter inside the packaging acts to control the reduction of CO2 gas, extending its useful life. Thus, this study aimed to evaluate the effect on packaging in a modified atmosphere with the inclusion of a CO2 emitter to prolong the useful life of red tilapia fillets (Oreochromis sp.). The specimens used came from the biofloc system cultivation of the Marine Aquaculture Station - FURG,Rio Grande, RS, which were headed, gutted, filleted and packed in plastic bags of high density ethylene alcohol-vinyl - EVOH. The samples were submitted to 5 treatments: A (control), B (Vacuum), C (Vacuum and CO2 emitter), D (100% CO2) and E (100% CO2 and CO2 emitter). The packaged samples were kept under refrigeration temperature, in the range of 5 ± 1 ° C, and evaluated at zero, 3, 8, 14, 21 and 30 days of storage. The fillets were analyzed for their proximal composition (moisture, protein, lipids and ash), texture, color, quality and stability (loss of mass, hydrogen potential - pH, lipid stability - TBA and total volatile bases - N-BVT), microbiological and sensory (MIQ). The results presented showed that the vacuum treatment showed greater mass losses,with maximum loss on the 30th day of storage. The treatment EAM and CO2 emitter showed an increase in pH, from the 14th day of storage, having its maximum (8.37) on the 21st day, generating its disposal. The N-BVT content was higher in the samples kept in the control, significantly higher on the 30th day (15.31 mg N-BVT / 100g). TBA indexes remained below 1.5 mg MA / Kg. The samples with CO2 emitter showed greater shear force on the 30th day (6.71 N). The color patterns fluctuated in the treatments during the storage period. Most treatments exceeded the limit proposed by the Legislation on the 30th day of storage (6.5 Log. UFC / g). During the storage period, the presence of Salmonella sp. From the results obtained,it can be concluded that treatment D (100% CO2) showed better results, extending the useful life for up to 30 days, ensuring the quality and safety of the red tilapia fillets within the limits acceptable by the current legislation.