Microencapsulation of bioactive compounds from avocado oil residues

• Ano de defesa: 2024
• Autor(a) principal: Gonzales, Camila Maria
• 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: Spray dryer; Encapsulamento; Encapsulation; Industrial waste; Optimization; Otimização; Resíduos industriais; Superfície de resposta; Surface response
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/11/11141/tde-07102024-135044/

Brazil is one of the largest global producers of avocado and, in addition to the consumption of the fruit, avocado oil has emerged as an alternative. In order to mitigate the by-products associated with the production of pressed oil, an approach was developed to take advantage of active compounds. This work presents a review in Chapter 1, focusing on the encapsulation of bioactive compounds from agro-industrial waste, the potential for reusing these wastes and their possible applications in the food and cosmetics industries. Chapter 2 presents the optimization of the extraction of bioactive compounds from avocado waste, with an emphasis on the adoption of clean technology principles and processes accessible to the avocado oil industry. To this end, the extraction was conducted using only water as solvent, in a stirring bath system. An experimental design of the central point rotational compound type (CCRD) was used to study the extraction parameters. The optimal conditions for the extraction of phenolic compounds and antioxidants from the residues were a temperature of 60°C and a solid/solvent ratio of 1 g/mL, where a maximum total phenolic content of 3.33 ± 0.22 mg EAG/ mL of extract. The antioxidant activity ranged from 6.44 to 22.40 µmol TEAC/mL of extract for the ABTS analysis and from 6.95 to 19.83 µmol FeSO4/mL of extract in the FRAP method. The phenolic compounds present in the extracts after optimization were analyzed using High Performance Liquid Chromatography (HPLC). The compounds identified were gallic acid, catechin, 4-hydroxybenzoic acid, 3,4-hydroxybenzoic acid, caffeic acid and p-coumaric acid. In Chapter 3, the extracts were microencapsulated and analyzed for their physicochemical, morphological characteristics and ability to retain phenolic compounds. The results showed that the microparticles obtained presented low water activity (Aw) (0.14 ± 0.002), high solubility (90.16% ± 0.08), and hygroscopicity of 53.71 ± 0.01 g of water absorbed /100 g of sample. The particles had an average size of 21.8 ± 0.44 m, the system encapsulation efficiency was 99.7% and satisfactory stability. The values of total phenolic compounds and antioxidant activities were lower when compared to other studies that used more aggressive and high-cost extraction methods. The spray dryer encapsulation technique proved to be efficient, presenting promising properties and industrial applicability. The results obtained indicate that, although the optimization and encapsulation strategy has demonstrated effectiveness in defining the best extraction parameters and protection of bioactive compounds, additional studies are needed to explore extraction approaches that favor sustainable and low-cost techniques.