Potencial tecnológico das espécies de pescados carpa capim, pacu e catfish: avaliação de aminoácidos, odor e textura

Abstract

Fish is highlighted as a significant nutritional source due to the presence of minerals, polyunsaturated fatty acids and proteins of high biological value. Although recognized as important food in several countries, including Brazil, there is a concern about its low consumption. There are several barriers cited as a possible cause, among them the characteristic odor of fish, often related to the freshness of the meat. The texture of raw meat is another attribute related to the quality and freshness of fish. As important as the knowledge of these attributes is the characterization of the amino acid profile. The knowledge about essential amino acid contents can be an important strategy for the promotion and dissemination of fish consumption habits. Currently, the southwestern region of the state of Paraná has great potential for development of fish farming, besides the tilapia production. Thus, the creation of other species, such as catfish, grass carp and pacu in concomitance or in the tilapia off season, would leverage the income of the small producer and strengthen the productive chain of fish farming in the region. In this context, the objective of this work was to characterize three species of fish: Grass carp (Ctenopharyngodon idella); pacu (Piaractus mesopotamicus) and catfish (Ictalurus punctatus), regarding the odor, texture and amino acid profile. At first, the odor of the three species was evaluated. With the assessors selected for odor analysis, the evaluation of the samples from pacu, catfish and grass carp occurred in two stages (1) generation of attributes by Grid method and (2) evaluation of samples by the Flash Profile method. The survey of terminology revealed the term "fish" as the most cited, followed by "pond water", "fat" and "rancid". The Flash Profile methodology provided quantitative characterization and discrimination of odor among species. Pacu was the species related to the terms earth, fat, plant, refrigerator and wood. Catfish, related to the most negative descriptors, was characterized by the terms earth, viscera, putrid, fat, burnt oil, blood, fish and acid. Grass carp was related to the terms pond water, fish, rancid, fat and grass. In a second moment the analysis of the instrumental texture profile was carried out by means of the texture analyzer TA-XT plus. The attributes hardness, cohesion, adhesiveness, gumminess, mastigability and resilience were evaluated through analysis of variance (ANOVA) and difference of means via Tukey test. The discriminant multivariate analysis was applied in order to further understand the differences between the three fishes. The results of mean differences revealed expressive texture differences among species, and the variables hardness, resilience and gumminess are the parameters that discriminated the texture better. In a third moment, the amino acid profile of the three fish species was characterized by high performance liquid chromatography (HPLC) and statistical treatment by the Tukey test (α = 0.05). Significant differences could be identified in the present amino acids among species, except the cysteine. The amino acid values, from the fish under study, when compared to FAO (Food and Agriculture Organization) standards were higher for most of the amino acids. From the obtained results it is possible to verify the technological potentiality of the fishes studied.