Qualidade microbiológica e físico-química de filés de tilápia tratados com solução de ozônio e cloro e armazenados sob refrigeração

Abstract

Fish are foods with high nutritional value for the human diet because they are rich in proteins, fats and minerals. However, these easily deteriorate due to the action of microorganisms even when stored in a refrigerated environment. In order to know the combined action of sanitizing solutions on the fillet, the antimicrobial and physicochemical action of aqueous ozone and chlorine in washing fillets immediately after application and its effects during storage time was investigated. The fillets were treated in an immersion bath for 5 minutes with demineralized water (T1), 5 ppm chlorine solution (T2), 5 ppm ozone solution (T3) and 5 ppm chlorine solution with 5 ppm ozone (T4). The immediate effects after treatments did not change the proximate composition or the pH of the fillets. There was a decrease in the microbial count of mesophiles by 0.49 log CFU.g-1 at T2 and 0.56 log CFU.g-1 at T4. T3 showed lower values of lipid oxidation, T1 and T3 showed lower values for total volatile base nitrogen (TVB-N). The treatments were not different during the storage time, there was an increase in lipids, a reduction in proteins, an increase in TVB-N, lipid oxidation and mesophilic and psychrotrophic counts. These results are expected due to microbial degradation during the storage period. In view of what was observed, the combined action of the sanitizer had superiority in the microbial control when compared to the control, but it was not able to promote the shelf life of the product.