Quality evaluation of pirarucu fillets (Arapaima gigas , Cuvier 1829), refrigerated and packed under modified atmosphere
Fish is a highly perishable food, and as such requires special care in its handling, being subject to contamination by various organisms. Under normal refrigeration conditions, the shelf life of the food is limited by the enzymatic, microbiological and oxidative deterioration processes, which limits its distribution and commercialization period. The effective consolidation of aquaculture depends on the flow of production, which in turn will depend on the demand for products. In order for the consumption of fish in Brazil to be increased, it is necessary to offer products with the quality required by the consumer. This study aimed to evaluate the effect on modified atmosphere packaging (EAM) in pirarucu fillets (Arapaima gigas). Specimens from cultivated areas in the State of Amazonas were used,from the Manacapuru region, Northern Brazil, which were processed, gutted, filleted and packed in plastic bags of high density ethylene-alcohol-vinyl - EVOH. The samples were submitted to 6 treatments: A (Control), 4 atmospheres containing approximately 0.5 L of air: B (100% CO2); C (40% O2/60% CO2); D (50% O2/50% CO2), E (30% O2/30% N2/40% CO2) and an F (vacuum). The packaged samples were kept under refrigeration, in the range of 2 ± 1oC, when they were subjected to analysis at zero times, 1,7,14,21,30,45 and 50 days of refrigerated storage in a heated oven. Physical-chemical analyzes (total volatile bases - N-BVT, pH), lipid stability (TBA), texture (shear strength), color and microbiological analyzes were performed.It was observed that the samples kept in aerobic (control) showed a rapid increase in the N-BVT values, with its maximum peak in the 50th day of storage (67.59 mg N-BVT/100 g). The production of N-BVT in the other treatments remained, throughout the storage period, around 21 mg of N-BVT/100g. The control samples showed an increase in pH, from the 30th day of storage, with its maximum value (6.98) on the 50th day. The treatments with modified atmospheres showed similar pH values during storage during storage and close to the initial pH (6.4). Most treatments exceeded the limit proposed by the legislation on the 30th day of storage (7 Log. Of UFC/g). During the storage period, neither Salmonella nor E. coli was detected. . The TBA indexes remained below 1,5 mg MA/Kg, the color patterns oscillated little and the texture (shear strength) varied between 2.39 and 6.88N. According to the results obtained, it can be concluded that packaging B (100% CO2), stood out from the others, presenting a good performance, extending the useful life for up to 45 days, being effective for maintaining the physical parameters -chemical and quality within the limits of acceptability proposed by current legislation.being effective for maintaining the physical-chemical and quality parameters within the limits of acceptability proposed by the current legislation.