Extraction of Anthocyanins and Total Phenolic Compounds from Açai (<i>Euterpe oleracea</i> Mart.) Using an Experimental Design Methodology. Part 3: Microwave-Assisted Extraction
María José Aliaño-González,
Marta Ferreiro-González,
Estrella Espada-Bellido,
Ceferino Carrera,
Miguel Palma,
Jesús Ayuso,
Gerardo F. Barbero,
José Á. Álvarez
Affiliations
María José Aliaño-González
Department of Analytical Chemistry, Faculty of Sciences, University of Cadiz, Agrifood Campus of International Excellence (ceiA3), IVAGRO, 11510 Puerto Real, Cadiz, Spain
Marta Ferreiro-González
Department of Analytical Chemistry, Faculty of Sciences, University of Cadiz, Agrifood Campus of International Excellence (ceiA3), IVAGRO, 11510 Puerto Real, Cadiz, Spain
Estrella Espada-Bellido
Department of Analytical Chemistry, Faculty of Sciences, University of Cadiz, Agrifood Campus of International Excellence (ceiA3), IVAGRO, 11510 Puerto Real, Cadiz, Spain
Ceferino Carrera
Department of Analytical Chemistry, Faculty of Sciences, University of Cadiz, Agrifood Campus of International Excellence (ceiA3), IVAGRO, 11510 Puerto Real, Cadiz, Spain
Miguel Palma
Department of Analytical Chemistry, Faculty of Sciences, University of Cadiz, Agrifood Campus of International Excellence (ceiA3), IVAGRO, 11510 Puerto Real, Cadiz, Spain
Jesús Ayuso
Department of Physical Chemistry, Faculty of Sciences, University of Cadiz, Institute of Biomolecules (INBIO), 11510 Puerto Real, Cadiz, Spain
Gerardo F. Barbero
Department of Analytical Chemistry, Faculty of Sciences, University of Cadiz, Agrifood Campus of International Excellence (ceiA3), IVAGRO, 11510 Puerto Real, Cadiz, Spain
José Á. Álvarez
Department of Physical Chemistry, Faculty of Sciences, University of Cadiz, Institute of Biomolecules (INBIO), 11510 Puerto Real, Cadiz, Spain
In this work, two methods based on microwave-assisted extraction techniques for the extraction of both anthocyanins and total phenolic compounds from açai have been developed. For that, a full factorial design (Box-Behnken design) has been used to optimize the following four variables: solvent composition (25−75% methanol in water), temperature (50−100 °C), pH (2−7), and sample/solvent ratio (0.5 g: 10 mL−0.5 g: 20 mL). The anthocyanins and total phenolic compounds content have been determined by ultra high-pressure liquid chromatography and Folin-Ciocalteu method, respectively. The optimum conditions for the extraction of anthocyanins were 38% MeOH in water, 99.63 °C, pH 3.00, at 0.5 g: 10 mL of ratio, while for the extraction of total phenolic compounds they were 74.16% MeOH in water, 99.14 °C, pH 5.46, at 0.5 g: 20 mL of ratio. Both methods have shown a high repeatability and intermediate precision with a relative standard deviation lower than 5%. Furthermore, an extraction kinetics study was carried out using extraction periods ranging from 2 min until 25 min. The optimized methods have been applied to açai-containing real samples. The results with such real samples have confirmed that both methods are suitable for a rapid and reliable extraction of anthocyanins and total phenolic compounds.
