Caracterização físico-química, microbiológica e rendimento do filé de Pseudoplatystoma fasciatum X Leiarius marmoratus

Abstract

Since fish meat is an essential part of human food, new species have been created, such as the actual painting, which has an increase in consumption due to its fast growth, low fat content and absence of thorns . The objective of this study was to characterize in a physico-chemical and microbiological manner the fillet of the hybrid Pseudoplatystoma fasciatum and Leiarius marmoratus, popularly known as real painting, cooled after collection and stored at -18°C for 180 days, at 0,30, 60,90,120,150 and 180 days. Analyzes of pH, water activity, color, shear force, amino acids, fatty acids, centesimal composition and microbiological analysis of Salmonella spp, Staphylococcus coagulase positive counts, and coliforms at 45 ºC, Escherichia coli, total bacteria and psychrophils and lipid oxidation (TBA). For the fillet yield analyzes, the total fish weight and fillet weight were obtained, both in grams. The average yield of the fillet of the actual painted hybrid was 38.11% ± 0.49. The values found in the physical-chemical analyzes after slaughter, where, moisture, protein, ash lipids, pH, Aw, color and shear force did not have significant difference compared with the literature. In relation to the amino acids, lysine, leucine, valine, theonine, phenylalanine were those that presented in greater concentration. The amounts of fatty acids present in the painted muscle had the following sums: ΣAGS (52.58 ± 0.62), ΣAGMI (60.32 ± 0.02), ΣAGPI (20.01 ± 0.02) and n-6 / n-3 (10,64). Microbiological counts for fresh and frozen fish were within national and international limits, susceptible to processing and / or consumption. For frozen fish (-18oC) and evaluated during the 180 days values varied for pH (6.23 ± 0.10 to 6.20 ± 0.00), water activity (0.997 ± 0.001 to 0.988 ± 0.00), color (L * 53.58 ± 1.56 to 43.33 ± 1.34, a * 3.14 ± 0.05 to -2.07 ± 0.01, b * 3.09 ± 0.01 to 6.20 ± 0.00), shear force (22.60 ± 1.92 to 8.39 ± 0.57). Mean TBARS values in this study showed a significant difference during the storage period (-18oC), varying from 0.15 to 0.53 mg of MDA kg-1 during the 180 days. The results indicated that the real painted fillet is classified as a fatty fish, with satisfactory microbiological, instrumental and physico-chemical quality and that they maintain these characteristics if stored frozen for 180 days.