Emprego de cultura pura de Staphylococcus xylosus e ultrassom para a obtenção de compostos bioativos a partir de subprodutos de frangos

• Ano de defesa: 2024
• Autor(a) principal: Nehring, Priscila
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; Ciência e Tecnologia dos Alimentos; UFSM; Programa de Pós-Graduação em Ciência e Tecnologia dos Alimentos; Centro de Ciências Rurais
• Palavras-chave em Português: Ultrassom; Staphylococcus xylosus; Compostos bioativos; Ultrasound; Bioactive compounds; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS
• Link de acesso: http://repositorio.ufsm.br/handle/1/33669

Although obtaining bioactive compounds from plant products is highlighted, few approaches have been made to obtain these compounds from products of animal origin, using clean technologies associated with pure culture. Ultrasound appears as a promising technique in this area. By defining ultrasound parameters and understanding the physical mechanisms of interaction between ultrasound, pure culture and meat, it becomes possible to innovate in the solution of bioactive compounds. In this context, the present project aims to evaluate the use of different frequencies, amplitudes and operating modes of ultrasound to obtain bioactive compounds, using pure culture in cooked chicken meat by-products. Initially, chicken meat by-products were sterilized in an autoclave at 121 ºC and then subjected to an ultrasonic bath. Subsequently, the parameters that influence the action of the ultrasonic bath were evaluated, including time (15, 30 and 45 minutes), operating mode (normal and degas), frequency (35 and 130 kHz) and amplitude (50% and 80%), in the development of pure culture of Staphylococcus xylosus incubated at 37 ºC for 0, 24, 48 and 72 hours. The results indicated that, under conditions of 35 kHz with 80% amplitude and 130 kHz with 50% amplitude, in normal operating mode and incubation time of 24 hours, there was growth of S. xylosus in cooked chicken by-products, reaching values of 8.23 CFU/g and 8.25 CFU/g, respectively, compared to the control, which presented 7.77 CFU/g. After defining the best conditions for ultrasound action in the development of pure culture in cooked chicken by-products, the volatile compounds, free amino acids and molecular weights of the proteins were evaluated. The combined action of ultrasound and the proteolytic activity of S. xylosus resulted in the formation of compounds with 25 kDa and a reduction in the amount of free amino acids, generating different volatile compounds. At 130 kHz, the compounds formed were characteristic of alcohols and aldehydes, while at 35 kHz carboxylic acids predominated. Samples subjected to TUS 130 ultrasound treatment for 30 minutes and incubated for 24 hours showed a total antioxidant activity of 19.62 ± 1.53 μmol TE/g. The samples treated with TUS 35, under the same incubation conditions, showed a total antioxidant activity of 16.69 ± 1.57 μmol TE/g, values higher than those obtained in the CONTROL 24 group (3.22 ± 0.11) μmol TE/g, all at a concentration of 2.0 mg/mL. This same pattern was observed in relation to antidiabetic activity, in the inhibition of the alpha-amylase enzyme. Treatments with TUS 130 (5.99 - 9.22%) and TUS 35 (8.78 - 10.57%) showed a higher percentage of enzyme inhibition (p <0.001) compared to the CONTROL 0 (2 .93 - 5.93%) and CONTROL 24 (1.56 - 4.67%), in all concentrations evaluated (0.5 - 2.0 mg/mL). With regard to inhibition of the alpha-glucosidase enzyme, treatments with TUS 130 (4.37 - 6.06%) and TUS 35 (2.43 - 3.28%) also showed a higher percentage of enzyme inhibition in comparison with the CONTROL 0 (1.01 - 1.69%) and CONTROL 24 (0.73 - 1.00%) groups, at all concentrations analyzed (0.5 - 2.0 mg/mL). In summary, the results obtained in all analyzes carried out demonstrated that ultrasound stimulated the growth of pure culture in cooked chicken by-products, making it possible to obtain new products with greater added value.