Identification of Sex-Dependent Aroma Compounds in Gonads of Commercially Valuable Sea Urchins: Implications for Gastronomical Use of Paracentrotus lividus

Background: The edible gonads of the sea urchin Paracentrotus lividus are highly valued, yet sex cannot be determined externally, limiting selective harvest and quality control. Objective: To test whether headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME–GC–MS) combined with chemometrics can discriminate sex from gonadal volatilomes. Methods: Gonads from 29 individuals (21 females, 8 males) were profiled by HS-SPME–GC–MS. Spectral data were modeled with Partial Least Squares–Linear Discriminant Analysis (PLS–LDA); Variable Importance in Projection (VIP) scores highlighted key features, and Mann–Whitney tests (FDR-adjusted) assessed univariate differences. Tentative identifications were assigned by library match and curated for potential environmental artefacts. Results: Chemometric modeling yielded a clear female–male separation. Female gonads were enriched in low-odour-threshold oxygenates—aldehydes (hexanal, heptanal) and alcohols (1-penten-3-ol, 1-octen-3-ol)—together with diet-linked monoterpenes (e.g., D-limonene), consistent with PUFA LOX/HPL pathways and macroalgal inputs. Male gonads were dominated by saturated/branched hydrocarbons and long-chain alcohols with limited direct odour impact. Minor aromatic hydrocarbons (e.g., styrene; 1,3-bis(1,1-dimethylethyl)-benzene) were retained as environmental/artefact markers and excluded from biological interpretation. Conclusions: HS-SPME–GC–MS volatilomics coupled with PLS–LDA effectively distinguishes the sex of P. lividus gonads and rationalizes reported sensory differences. The marker set offers a basis for future non-destructive sexing workflows, pending confirmation with retention indices, authentic standards, and GC-olfactometry.