High-throughput extraction method for phenolic compounds in olive fruit ( Olea europaea )

Abstract Phenolic compounds in olive fruit significantly influence the health benefits and sensory properties of processed olive oil and table olives. A simple and rapid extraction method using homogenization with dimethyl sulfoxide (DMSO) and solid-phase extraction (SPE) cleanup was developed and optimized for ten phenolics in olive fruit. Quantification was performed using high-performance liquid chromatography with diode-array detection (HPLC-DAD). Chromatographic separation of the relevant compounds was achieved using a C18 column (5 μm, 4.6 × 250 mm). The method was validated for accuracy and precision using replicate fortifications (n = 5) in 3 olive matrices (fresh, brined and California-style olives). All compounds were recovered between 80 and 120% and had relative standard deviations below 12.5%. Limits of detection (LOD) and limits of quantification (LOQ) ranged from 0.06 to 7.4 mg/kg and 0.20 to 23.3 mg/kg, respectively. The method was used to quantify phenolic concentrations in fresh olives at different maturities, brined olives and California-style olives, including the analysis of green ripe olives and black ripe olives processed without ferrous gluconate for the first time.