Unraveling the Aromatic Profiles of Longnan Olive Oils: A Complementary HS-GC-IMS and HS-GC-MS Analysis for Varietal Discrimination

This study employed a complementary analytical approach, combining headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS) and headspace gas chromatography–mass spectrometry (HS-GC-MS), to comprehensively characterize the dynamic evolution of volatile organic compounds (VOCs) in virgin olive oil (VOO) from Chenggu 32 (CG-32) and Koroneiki (KK) cultivars across eight maturity indices (MIs). The combined strategy proved powerful: HS-GC-IMS detected 90 VOCs, excelling in profiling polar, aroma-active compounds, while HS-GC-MS confirmed 61 VOCs, providing broader metabolome coverage. Multivariate statistical analysis revealed that genetic cultivar is the primary driver of VOCs profile divergence. The CG-32 variety was characterized by a high abundance of aldehydes, imparting classic “green” notes, whereas the KK variety was dominated by ketones, resulting in a less traditional, intense aroma. Notably, a key finding was that genetic factors can override ripening trends, as evidenced by the late-harvest KK sample clustering with the early-harvest CG-32 sample based on VOCs signature. Orthogonal partial least squares-discriminant analysis (OPLS-DA) models exhibited exceptional predictive power ( Q 2 > 0.94) for varietal authentication, and a set of 35 key discriminatory markers (VIP > 1.0) was identified. This work underscores that MIs alone is an insufficient harvest guide and establishes a robust foundational methodology for VOCs-based quality control and varietal screening of olive oils. The high predictive power of the models demonstrates their potential for authenticity purposes, which now warrants validation with a larger sample set. Graphical Mapping the aroma of virgin olive oil: A dual-technique approach. HS-GC-IMS/MS analysis of two cultivars across eight maturity stages uncovered 35 key VOCs dictating oil identity and maturation. Multivariate modeling enabled precise differentiation, establishing a novel method for quality and authenticity verification.