Summary
This study aimed to evaluate the effect of modified atmosphere packaging associated with ascorbic acid on the shelf life of Nile tilapia fillets, and to determine the most effective treatment for their conservation. To this end, fillets of this species were subjected to four different treatments: T1 (control) aerobically, T2 (1% ascorbic acid + 80% CO2 + 20% O2), T3 (1% ascorbic acid + 100% CO2) and T4 (1% ascorbic acid + vacuum). The samples were subsequently stored at 4 ± 1°C and subjected to microbiological, physical-chemical and sensory evaluations at different intervals. The T3 and T4 treatments were more effective in inhibiting the development of psychrotrophic bacteria and the coliform group of microorganisms with time in the samples analyzed, the presence of Clostridium sulfite reducers not being detected in the fillets of either treatment. However, the results for pH, NTVBs and TBAs showed that treatment T4 stood out as compared to treatment T3, maintaining the freshness features unchanged for a longer time. The results of the sensory analysis showed a reduction in the average scores with time for all the attributes assessed, being significantly affected during the storage period (p<0.05). The sensory evaluation delimited the shelf life of the samples, treatment T4 treatment maintaining better mean scores for a longer period of time of 18 days. Correlating the results of the microbiological, physical-chemical and sensory analyses, it was concluded that treatment T4 (1% ascorbic acid + vacuum) was more effective and therefore the most suitable for the conservation of refrigerated Nile tilapia fillet.
Keywords:
Sensory acceptance; Psychrotrophic bacteria; Vacuum