Recovery of active compounds from avocado oil residues: sustainable alternatives for obtaining new ingredients

• Ano de defesa: 2022
• Autor(a) principal: Teixeira, Bianca Ferraz
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Antioxidant capacity; Avocado oil; Capacidade antioxidante; Óleo de abacate; Optimization; Otimização; Resíduos; Response surface; Superfície de resposta; Waste
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/11/11141/tde-12072022-151732/

During the fruit oil processing, such as the avocado oil, only the pulp is used, while the peel, seed and the solid fraction of the pulp (pomace) are generally discarded as waste. However, these residues are promising sources of bioactive compounds, with potential application as functional ingredients in the food and cosmetics industry, due to the high content of phenolic compounds and the high antioxidant capacity. Therefore, the obtention of compounds of interest should be studied in a holistic way, in which all stages of the process of obtaining bioactive ingredients are efficient and friendly to the environment. Thus, this dissertation aimed to optimize the process for the recovery of bioactive compounds, such as phenolic compounds, from the residues of avocado oil extraction, adding value to discarded materials. Hence, in Chapter 1, a review is presented on the processing of avocado oil, the main residues generated during processing, the potential for reuse of these residues as a source of bioactive compounds and the possible applications of these compounds in the food and cosmetics industries. Chapter 2 presents the optimization of obtaining bioactive compounds from avocado oil production, of the Breda variety, through ultrasound-assisted extraction. The response surface methodology with a central composite rotatable design (CCRD) was used to optimize the experimental variables (ethanol concentration (%), temperature (°C) and solid/solvent ratio (g/mL)). The extraction of phenolic compounds and tannins was significantly (p < 0.05) influenced by the ethanol concentration and the solid/solvent ratio. Temperature did not significantly influence the extraction yield, so the temperature of 30°C was chosen for energy-saving reasons. The extracts obtained under optimized conditions were characterized as the content of total phenolic compounds (TPC), antioxidant activity (DPPH, ABTS, and FRAP), antimicrobial activity and phenolic compounds (3,4-dihydroxybenzoic, 4-hydroxybenzoic, caffeic, syringic acid and catechin). For the peel, the optimal concentration of ethanol was 40%, temperature of 30°C and the ratio of solid/solvent of 0.225 g/mL. For the seed, the optimal conditions were 20% ethanol, 30°C and a ratio of solid/solvent of 0.5 g/mL. Both extracts showed high antioxidant activities, however, they were not effective in inhibiting the microorganisms studied. In addition, it was possible to identify high concentrations of phenolic compounds in the optimized extracts. Thus, the results indicate that the extracts obtained can be considered a good sustainable bioactive source for food and cosmetic purposes.