Phenolic Profiling of Olive (Olea europaea L. cv. Nocellara Messinese) Samples by Comprehensive 2D Liquid Chromatography

The comprehensive profiling of phenolic compounds in olive matrices provides crucial insight into their distribution, transformation, and contribution to the chemical and sensory properties of olive products. In this work, a comprehensive 2D reversed phase ×reversed phase liquid chromatography (RP-LC ×RP-LC) method coupled with photodiode array (PDA) and tandem mass spectrometry (MS/MS) was applied to the comparative characterization of phenolic compounds in Olea europaea L. cv. Nocellara Messinese samples, namely, drupe, leaves, pomace, and extra virgin olive oil (EVOO). A total of 52 phenolic compounds, belonging to major subclasses such as phenylethanols, secoiridoids, phenylpropanoids, and flavonoids, were identified or tentatively characterized. Distinct distribution patterns were observed across matrices, highlighting the accumulation of oleuropein derivatives in drupes and the selective enrichment of flavonoids in leaves. Compared to conventional RP-LC-PDA- MS analysis, the RP-LC ×RP-LC-PDA-MS/MS platform provided improved chromatographic resolution. The developed workflow confirms the analytical power of the RP-LC ×RP-LC in unveiling the complex phenolic pattern of olive-derived materials and provides a basis for targeted valorization of olive by-products in food chemistry.