Composition and Biological Activity of Extracts Obtained by Three Green Technologies from Residues of the Avocado (Persea americana, Mill.) Oil Industry

The avocado oil industry discards residues from the peeling and destoning steps primarily as mixtures with high biofunctional potential. Extracts from a residual avocado oil industry (RAOI) mixture were evaluated for the effects of green technologies Naviglio® (rapid solid–liquid dynamic extraction), ultrasound, and maceration on their functional compounds and biological activity. The Naviglio® extract excelled for total flavonoid content (7.29 ± 1.09 mg QE/g), minimum inhibitory concentration (MIC) against Escherichia coli (25 mg/mL) and Staphylococcus aureus (25 mg/mL), and minimum bactericidal concentration (MBC) against Staphylococcus aureus (50 mg/mL), with similar anti-inflammatory activity and total phenolic content (17.32 ± 0.59 mg GAE/g) than the maceration extract. Maceration was superior in seven polyphenol contents, β-sitosterol (9135.87 ± 468.83 mg/kg), and antioxidant activities (116.71 ± 16.09, 63.85 ± 3.97 and 49.63 ± 1.83 µmol TE/g for ABTS, FRAP and DPPH, respectively). At the evaluated MIC and MBC, the Naviglio® extract was non-toxic, while maceration and ultrasound extracts were moderately toxic; at the anti-inflammatory concentrations tested, the Naviglio® and ultrasound extracts were non-toxic. Naviglio® and ultrasound extracts have pharmaceutical potential as antioxidants and anti-inflammatory agents, while the macerated extract is a potential source of β-sitosterol. For the first time, Naviglio® technology was applied to RAOI mixtures, and the biological properties of the extracts were evaluated.