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: We aimed to test whether headspace solid-phase microextraction gas chromatography–mass spectrometry combined with chemometrics can discriminate sex from gonadal volatilomes. Methods: Gonads from 29 individuals (21 females, 8 males) were profiled by this technique. Spectral data were modeled with Partial Least Squares–Linear Discriminant Analysis (PLS–LDA), Variable Importance in Projection scores highlighted key features, and Mann–Whitney tests assessed univariate differences. Tentative identifications were assigned by library match and curated for potential environmental artifacts. Results: Chemometric modeling yielded a clear female–male separation. Female gonads were enriched in low-odor-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 odor impact. Minor aromatic hydrocarbons (e.g., styrene; 1,3-bis(1,1-dimethylethyl)-benzene) were retained as environmental/artifact markers and excluded from biological interpretation. Conclusions: HS-SPME gas chromatography–mass spectrometry 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.