Patê funcional de tambica (Oligosarcus robustus) e viola (Loricariichythys anus): estabilidade oxidativa, qualidade microbiológica e sensorial

Abstract

Fish are important components in human nutrition, as they provide a diet rich in proteins, micronutrients, and polyunsaturated fatty acids (PUFAs). The chemical composition of fish pâté is rich in PUFAs, making it more susceptible to lipid oxidation, consequently developing an unpleasant aroma and flavor due to generating of rancid compounds contributing to off flavors. Therefore, the objective of the study was to evaluate the oxidative stability, the microbiological and sensory quality of tambica (Oligosarcus robustus) and viola (Loricariichthys anus) pâté, containing Lactobacillus acidophilus and fructooligosaccharides, during the refrigerated storage period. For the experiment, a completely randomized statistical design was carried out, where analyses of pH, titratable acidity, peroxide index (PI), thiobarbituric acid reactive substances (TBARS), determination of fatty acids, volatile organic compounds (VOCs), count of psychrotrophic and mesophilic aerobic bacteria, viability of L. acidophilus LAFTI L10, evaluation of microbiological parameters and sensory analysis were organized in a bifactorial scheme, carried out with biological repetition. The analyses were done immediately after preparing the pâtés (0 days) and at 15, 30, 45, and 60 days of refrigerated storage. In both pâtés, throughout storage, there was an increase in acidity and a reduction in pH. In terms of hygienicsanitary aspects of pathogenic microorganisms, they were satisfactory, and in terms of microbiological quality, mesophilic aerobes showed a reduced count and absence of psychrotrophic, and the viability of L. acidophilus remained higher than 9 log CFU g-1 until the end of the storage period. Regarding the analyzes of IP, TBARS, fatty acids, volatile compounds, and sensory analysis, for tambica pâté, oxidation was not noticeable by the panelists during the 60 days of storage, thus corroborating the results of 2,39 mEq/kg (IP) and 0,55 mg MDA/kg (TBARS). In the viola pâté, at time 45, the panelists noticed a rancid taste, corroborating the PI results of 4,6 mEq/kg and the presence of the nonanal compound (a marker of lipid oxidation). As for fatty acids, arachidonic acid, and α-linolenic acid in the present study showed a significant reduction in both pâtés when analyzed at t0 and t60 in the storage period, signaling lipid oxidation, while linoleic acid remained stable during the 60 days of storage. In the analysis of principal components (PCA), it is possible to infer that mesophilic aerobes (AM), pleasant taste (NT), undecane (V11), decanal (V12), and nonanal (V14) had a higher level of contribution in generating the main components. There were negative attributes related to microbial count, acidity and oxidation; however, the rates were low. Therefore, it is concluded that it is possible to produce a functional product based on fish with fructooligosaccharides and L. acidophilus LAFT L10, safe, with quality and oxidative stability for 45 days for viola pâté and 60 days for pâté also, with refrigerated storage.