Eficiência de pré-lavagem de tambaqui (Colossoma Macropomum) com água hiperclorada para redução de Salmonella spp

Abstract

The microbiological safety of fish as food is a concern for consumers, industries and regulatory agencies worldwide. The pathogenesis by Salmonella spp. derived from fish is responsible for serious infections through inadequate handling or hygiene in the Fish Processing Unit or through contact with water contaminated by a biological agent that is not originally related to fish. The objective of this work was to evaluate the efficiency of washing tambaquis (Colossoma macropomum) in a rotating cylinder to reduce Salmonella spp. and propose a new initial washing protocol considering free chlorine concentration and washing time. For this, fish were experimentally contaminated with a Salmonella solution with an initial concentration of 1.5 x 106 CFU/mL and 20 treatments were tested, which consisted of washing only with water and washing with different concentrations of chlorine (2, 5 and 10 ppm) with 5 washing times (20, 40, 60, 120 and 180 seconds) in the rotating cylinder, and the colorimetry of the fish was performed after washing them in the cylinder, using the washing treatment that did not grow of Salmonella colonies. Statistics showed that there was no significant difference between treatments with different concentrations of chlorine, but there was a significant difference between washing times, demonstrating a reduction in Salmonella as the washing time increased. The experiment showed that in the time of 180 seconds at a concentration of 10 ppm of chlorine there was no growth of Salmonella colonies on the plate after washing, which meets the provisions of the legislation, absence of Salmonella in 25g of fish. As there was a color change in the fish with this treatment, future research should be carried out to verify consumer acceptability.