Camellia sinensis extract delays microbiological and oxidative changes in striped catfish fillets during frozen storage/Extrato de cha verde age sobre a qualidade de files de pescado durante o armazenamento por congelamento

This study investigated the effects of tea leaf (Camellia sinensis) extract on the quality of striped catfish (Pangasianodon hypophthalmus) fillets during 18-months of frozen storage (-20 [+ or -] 2 [degrees]C). Fillet samples were submitted to the treatments Control (cold tap water), CS 7.63 (C. sinensis extract solution 7.63 [micro]g / mL) and CS 625 (C. sinensis extract 625 [micro]g / mL) and stored for 18 months, with collections performed at 0, 1, 3, 6, 9, 12 and 18 months. Total viable count, physicochemical parameters (water holding capacity, total volatile basic nitrogen, peroxide value, thiobarbituric acid reactive substances, moisture and pH), sensory properties and color measurement were evaluated. Results showed that fillets treated with C.a sinensis extracts slightly reduced lipid oxidation, inhibited bacterial growth and improved sensory properties compared to untreated samples, without causing significant changes in the other quality indicators. The findings indicated that the green tea leaf extract immersion treatments, contributed to the improved quality preservation of striped catfish fillets during frozen storage. Key words: Camellia sinensis, extract, frozen storage, striped catfish. O objetivo deste estudo foi investigar os efeitos do extrato de folhas de cha verde (Camellia sinensis) na qualidade de files de bagre listrado (Pangasianodon hypophthalmus) durante 18 meses de armazenamento congelado (-20 [+ or -] 2 [degrees] C). O estudo incluiu tres tratamentos: imersao dos files de bagre listrado em agua fria da torneira como um tratamento de controle, em solucao de extrato de Camellia sinensis 7,63 [micro]g/mL e em solucao de extrato de Camellia sinensis 625 [micro]g/mL. As amostras foram armazenadas por 18 meses e as coletas foram feitas aos zero, um, tres, seis, nove, 12 e 18 meses. Os parametros avaliados incluiram contagem viavel total, parametros fisico-quimicos (capacidade de retencao de agua, nitrogenio basico volatil total, valor de peroxido, substancias reativas ao acido tiobarbiturico, umidade epH), propriedades sensoriais e medicao de cor. Os resultados mostraram que os files de bagre listrado tratados com extratos de Camellia sinensis reduziram ligeiramente a oxidacao de lipidios, inibiram o crescimento de bacterias e aumentaram as propriedades sensoriais em comparacao com as amostras nao tratadas. Alem disso, o tratamento do extrato de Camellia sinensis nao afetou o pH, a umidade, a capacidade de retencao de agua, o nitrog