Recovery of bioactive compounds from Arbutus unedo L. fruits: comparative optimization study of maceration/microwave/ultrasound extraction techniques

17pages, 4 tables, 4 figures

The aim of this work was to produce an extract rich in different bioactive compounds from Arbutus unedo L. fruits to enhance its possible valorization and commercialization. The conditions of the main variables of maceration, microwave, and ultrasound assisted extractions (MA, MAE and UAE, respectively) were optimized and compared in terms of its composition (based on the total material extracted, total content in carbohydrates, phenolic and flavonoid compounds) and its preservative potential (based on the response of four in vitro antioxidant assays). The key variables of each extraction technique (time, temperature or power and hydroalcoholic mixture) were evaluated by specific experimental designs using response surface methodology. Mathematical models were developed and numerical optimal values for each extraction technique and response were achieved. Regarding the extraction of target compositional compounds, MAE was the most efficient, closely followed by MA. In terms of its preservative potential, MAE was the most suitable solution, but MA gave similar results at lower temperatures (~90 °C). Globally, MA and MAE were the best options conducting to optimal solutions using reduced amounts of ethanol. UAE required higher ethanol contents (~60%). The results showed alternatives to obtain extracts of A. unedo fruits, supporting their potential to be exploited at industrial level

The authors thank the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013) and L. Barros contract. The authors are also grateful to FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E; and to the European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE. To POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by FEDER, through POCI-COMPETE2020 and FCT. To Xunta de Galicia for financial support for the post-doctoral researcher of M.A. Prieto

Peer reviewed