Comprehensive Characterization and Chemometric Valorization of Tunisian <i>Chemlali</i> Olive Oil through Physicochemical, Volatile, and Sensory Analyses

High Resolution Image Download MS PowerPoint Slide This study investigates volatile and sensory profiles of Chemlali virgin olive oil (VOO) for premium market positioning. Ten samples from two seasons (2022/2023 and 2023/2024) across five Tunisian regions (Sfax, Boughrara-Sfax, Mahdia, Sidi-Olwane-Mahdia, Kairouan) were analyzed by GC-MS and a trained sensory panel. All samples complied with extra virgin standards. Oleic acid (C18:1, 56.04–60.82%) was predominant, followed by linoleic (15.10–18.51%) and palmitic (16.31–19.91%) acids. Sterol profiling revealed high β-sitosterol (77.72–84.00%) and Δ5-avenasterol (8.83–14.19%), confirming authenticity and oxidative stability. Lipoxygenase (LOX)-derived volatiles─notably ( E )-2-hexenal (up to 86.64 mg/kg), 1-hexanol, and ( Z )-3-hexenyl acetate─strongly correlated with sensory descriptors (fruity, almond, apple, green-leaf), confirming lipoxygenase pathway dominance. Chemometrics discriminated samples by season and region, revealing distinct aroma–composition patterns associated with antioxidant content and freshness. Sensory evaluation detected no defects, with fruitiness peaking at 4.9. These findings confirm Chemlali olive oil’s compositional adaptability, supporting geographical indications for premium market recognition.