Conservação de tambaqui (Colossoma macropomum–Cuvier 1818), refrigerado em atmosfera modificada com ozônio

Abstract

The Tambaqui (colossoma macropomun – Cuvier 1818) is an extremely important freshwater fish for the state of Amazonas, especially for commercial fish farming. Biochemical events resulting from the capture, manipulation, transport and commercialization processes result in the deterioration of fresh fish and can be used for the physic-chemical evaluation of the degree of freshness through analytical procedures. Due to the need for alternatives for reginal fish conservation, the present study had the objective of storing whole tambaqui under refrigeration (± 2oC temperature and 75-80% relative humidity) with atmosfere modified by ozone gas (1,5 ppm) for 30 days where the variable response were analyzed at 10-day intervals between collections (00, 10, 20 and 30 days). There was analyzed microbiological variables as counting of mesophilic and psychrophilic counts, total NPM and and NPM 45ºC, Salmonella spp and Staphylococcus coagulase positive, and physico-chemical variables (pH, N-BVT, TBA and peroxide index). It was observed that the initial psychophilic bactéria count was 2,25 log CFU/g and the final count was 2,87 log CFU/g for the control group and 2,44 log CFU/g for rhe ozone treated group. For the mesophilic bactéria counts the initial values were 2,5 log CFU/g and final count 2,56 log CFU/g for the control group and 2,12 log CFU/g for the ozone group. Regarding total and faecal NMP in both treatments the samples were negative, as well as, for Salmonella spp and coagulase posite Staphylococcus. For de pH variable the initial values were 6,32 and the final ones were 6,31 for the control group and 6,18 for the ozone treated group. In relation to N-BVT, the initial results in both treatments were 5,82 mg/N/100g and the final results were 10,90 mg/N/100g for the control group and 7,74 mg/N/100g for the ozone group. The initial values for TBA in both treatments were 0,64 mgMA/Kg, increasing gradually until reaching a maximum of 3,37 mgMA/Kg for the control group and 2,03 mgMA/Kg in the musculature of tambaquis treated with ozone. For the peroxide index the initial values in both treatments were similar 0,047 meq/Kg and the final values were 3,15 meq/Kg for the control group and 0,94 meq/Kg in the ozone treated group. It was concluded that whole tambaquis treated in atmospheres with ozone modified atmosfere (1,5 ppm) in cold room (± 2oC temperature and 75-80% relative humidity, for 30 days presented better quality tham the untreated fish, evidencing that the Ozone provides na increase in product quality.