Estudo de diferentes técnicas ultrassônicas para extração dos compostos fenólicos de folha de bambu (Dendrocalamus asper)

• Ano de defesa: 2024
• Autor(a) principal: Reis, Andreara Rodrigues dos
• Tipo de documento: Dissertação
• 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: Extração verde; Otimização; Bambu; Bioativos; Green extraction; Optimization; Bamboo; Bioactives; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS
• Link de acesso: http://repositorio.ufsm.br/handle/1/33465

Bamboo is a sustainable plant with cultural, ecological, economic, and nutritional value. The growing interest in natural bioactive compounds has encouraged studies on the extraction of these compounds, especially from bamboo leaves, which contain phenolic compounds with antioxidant potential. This study aims to assess whether ultrasonic-assisted extraction of bamboo leaves (Dendrocalamus asper), using green solvents, results in extracts with higher concentrations of phenolic compounds, high antioxidant capacity, and low production costs. Factors such as solid/liquid ratio, green solvents, and ultrasonic frequencies for phenolic compound extraction and economic evaluation were investigated. Both ultrasonic bath and ultrasonic probe were used, with a rotational central composite design. In bath extraction, the independent variables were amplitude, time, and temperature, while the probe tested two power levels (130 W and 750 W), with phenolic concentration as the response variable. The results obtained from the extraction techniques were compared with mechanical agitation extraction in terms of phenolic concentration (TPC), antioxidant capacity, and associated costs. The phenolic profile of the optimized extract was characterized by LC-ESI-QqQ-MS/MS. The optimized conditions were established at 0.4 g of lyophilized sample in 50 mL of solvent (distilled water), with ultrasonic bath-assisted extraction standing out as the most effective technique compared to the others and mechanical agitation, leading to an extraction time of 14 minutes, 60% amplitude, and 25 ºC temperature. The extraction yield of TPC was 1176.107 ± 33.105 mg of gallic acid equivalent per 100 g of bamboo leaves, with an antioxidant capacity of 23.680 ± 1.352 mmol of trolox per 100 g of bamboo leaves. The predominant classes were flavones and hydroxycinnamic acids, with orientin and 5-O-feruloylquinic acid standing out in their respective classes. Based on this, the extract obtained presents a high extraction yield, being efficient, fast, and economical. Manufacturing costs were lower than those of other ultrasonic techniques due to higher raw material processing and lower energy consumption (100 W, compared to 130 W or 750 W). These characteristics make it feasible for application in the food industry