Physical-chemical and freshness characterization of nile tilapia (Oreochromis niloticus) fillets from extractive catching in the medium Tietê River/SP, Brazil

Abstract

For increasing the fish consumption in Brazil is necessary offer products with quality control to guarantee food safety to the consumers. The Medium Tietê river region is the largest producer of Nile tilapia (Oreochromis niloticus) from catching in the São Paulo state and, thus, the aim of this research was to evaluate the physical-chemical parameters (protein, moisture, lipid, ash and freshness (no protein nitrogen, total volatile base nitrogen - TVB-N and pH) in fish fillets - Anhembi, Botucatu and Igaraçu do Tietê. The data were examined further using random blocks design and submitted to test of variance analysis and Tukey Test for comparison of means. The data showed significant difference (5%) among the places, for the centesimal composition and freshness, being found the following medium values: moisture (77.9 to 81.69 g/100 g), protein (13.72 to 18.25 g/100 g), lipids (0.6 to 1.9 g/100 g), ash (0.6 to 1.0 g/100 g), NNP (61.6 to 78.0 mg/100 g), pH (6.2 to 6.4) and TVB-N (5.0 to 10.5 mg/100 g). The values found in the physical-chemical and freshness analysis are in accordance with Brazilian legislation, and the processing of fish in the places studied are irregular and cannot guarantee food safety to the consumers and the quality of the product.