Recovery of bioactive components from avocado peels using microwave-assisted extraction

[Display omitted] •Avocado peels are an agroindustrial residue largely produced without a useful valorization.•MAE is an effective technology to obtain extracts with high antioxidant potential.•Statistical designs allowed to optimize the MAE conditions to bioactive compounds.•Procyanidins, phenolic acids and catechin are the main compounds identified. The avocado processing industry generates large amounts of avocado peels, which contain large amounts of high value-added compounds with antioxidant capabilities that have not yet been explored. Optimization of microwave-assisted extraction (MAE) of bioactive compounds from avocado peels with high antioxidant capacity was the objective of present work. Two experimental designs were implemented, using acetone 70% and ethanol at different concentrations, finding at 74.48 °C by 14.32 min and 66.37 °C by 0.97 min with 42.58% of ethanol as optimal conditions to obtain the highest antioxidant capacity, respectively. Optimized extracts with acetone and ethanol showed a high polyphenolic content (379.28 ± 19.35 and 354.43 ± 16.85 mg GAE/g dry extract, respectively); high antioxidant activity measured by DPPH (268.04 ± 25.11 and 233.85 ± 13.58 mgET/g dry extract, respectively); ABTS (895.19 ± 30.41 and 949.41 ± 7.42 mgET/g dry extract, respectively); ORAC (648.88 ± 28.66 and 692.06 ± 28.80 mgET/g dry extract, respectively), results reported for the first time. Fiber bonded phenolics compounds was extracted of MAE residues show a significant antioxidant activity. HPLC-MS analysis of optimized extracts showed the present of diverse phenolic acids, numerous procyanidins dimer A and B in different isomer shapes, catechin, epicatechin and perseitol.