Strategies for the purification of hydroxytyrosol-rich extracts obtained from exhausted olive pomace

• Autor(a) principal: Gómez Cruz, Irene
• Data de Publicação: 2023
• Outros Autores: Contreras, Maria del Mar, Romero, Inmaculada, Ribeiro, Belina, Roseiro, Luisa B., Duarte, Luís C., Carvalheiro, Florbela, Castro, Eulogio
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.9/4240
• topic: Adsorption; Antidiabetic; Hydroxytyrosol; Liquid-liquid extraction; Membrane purification

ABSTRACT: Exhausted olive pomace (EOP) is a residual biomass from which hydroxytyrosol can be recovered. This compound has applications in the food/pharma sectors, but its extraction yields complex extracts that require further purification for some applications. This work explores purification strategies based on membrane technology, liquid–liquid extraction (LLE), and solid-phase extraction with adsorbents and resins. The hydroxytyrosol content, phenolic profile, antioxidant activity, and inhibition of α-glucosidase and α-amylase were monitored. Hydroxytyrosol stood out in all purified extracts. The best hydroxytyrosol recovery (88.8%) was achieved using LLE with ethyl acetate as the extractant, while the purest extracts in phenolic compounds, including hydroxytyrosol, were obtained using the latter solvent and C18 (529 mg/g), DSC-8 (873 mg/g), and Purosorb PAD910 (523 mg/g). Conversely, mannitol and glucose, at high concentrations in the extract, were selectively retained in the aqueous phases. The developed strategies are discussed regarding their suitability to provide hydroxytyrosol-concentrated extracts, up to 291 mg/g, with antioxidant and antidiabetic functionalities.