Abstract: Rancid taste, pH, and TBARS are important quality parameters of food oxidation, analyzed in a time-consuming and destructive way. Non-destructive characterization of food can be achieved correlating this data with computational vision. Thus, the present study aimed to use RGB digital images to predict sensory rancid taste, pH, and TBARS results in fish burgers. A mobile obtained the digital images, in a controlled environment, and 768 grayscales were performed using RGB histograms. The pH, showed a peak at 21st day of storage, which PCA confirmed by isolating the 21st samples, corroborated by HCA grouping 21st day samples. PLS models from RGB digital images and sensory rancidity, pH and TBARS data, using mean center method and SIMPLS algorithm found models with > 0.97 R2. Thus, any digital image of this batch of burgers, inserted into the model to predict rancid taste, pH and TBARS has high confidence level of prediction.
In Brazil, 47% of the fish farming correspond to the tilapia species, and the main producers are the south and northeast regions. This work aimed at characterizing the amino acid profile of three fishes with the potential for rearing and diversification in Brazil and worldwide. The fishes grass carp (Ctenopharyngodon idella), pacu (Piaractus mesopotamicus), and catfish (Ictalurus punctatus) were obtained from a rural property located in the city of Pato Branco, PR, Brazil, and analyzed regarding the amino acid composition through High-Performance Liquid Chromatography. The amino acid profile showed the presence of glutamic acid, followed by lysine, aspartic acid, and leucine as the most prominent amino acids for the three fishes. Among the studied species, the grass carp presented the highest content of essential amino acids, registering all values superior to the minimum recommendation standards determined by the Food and Agriculture Organization of the United Nations (FAO). The disclosure of the significant nutritional value presented by these species consolidate their protein quality and expand possibilities to improve the fish farming and development of derivative products.
Fish has a high nutritional value and its regular consumption is associated with lower probabilities of cardiovascular diseases. Brazilians are characterized as low fish consumers, and the fish odor significantly affects the consumer acceptance or rejection. Grass carp, catfish and pacu are three fishes with high potential of farming in the Southwestern region of Paraná, Brazil, and worldwide. The characterization of their odor profile using the Flash Profile technique is the focus of this study. With assessors selected for odor analysis, the assessment of samples of the three species of fish was carried out in two stages (1) generation of attributes using the Grid method and (2) evaluation of the fish samples, according to attributes individually selected, with 9 cm unstructured and anchored scales. The data was processed by using generalized procrustes analysis. A total of 19 selected assessors were able to recognize and describe the stimuli perceived by the different substances. The terminology surveyed revealed the term "fishy" as the most cited, followed by "pond water", "fat" and "rancid". Flash Profile provided a precise odor characterization and discrimination with quantitative differences among the fishes. Pacu was the species related to the terms earth, fat, plant, fridge and wood. Earth, viscera, putrid, fat, burnt oil, blood, fishy odor and acid characterized the catfish, related to the most negative descriptors. Grass carp was associated to the terms pond water, fishy odor, rancidity, fat and grass.
