The Volatile Profile and Seasonal Shifts of Greek-Grown Yuzu (Citrus junos) Peels and Leaves

This study presents the first characterization of peel and leaf essential oils (EOs) from Citrus junos Sieb. ex Tanaka (yuzu) cultivated in Greece, evaluating seasonal maturation effects on their chemical profiles. EOs were extracted through hydrodistillation from samples harvested between September and November (stages H1–H3) and analyzed via GC-MS, identifying 32 and 38 volatile compounds in peel and leaf EOs, respectively. High yields were recorded for both peels (1.00–1.27%, peaking in H2) and leaves (0.28–0.39%, peaking in H1), exceeding values reported for East Asian and Mediterranean cultivars extracted through conventional methods (0.09–0.27% for peels; 0.04% for leaves). Peel EO matched the traditional yuzu chemotype, dominated by limonene (62.62–67.32%) and γ-terpinene (10.95–14.24%), but lacked β-phellandrene and contained higher amounts of thymol and sesquiterpenes. Early-stage peels (H1) were characterized by linoleic acid (2.26%), which cleared in subsequent months, indicating a marker for fruit immaturity. In contrast, leaf EO displayed a distinct profile dominated by β-phellandrene (27.92–29.60%), γ-terpinene (20.43–24.06%) and p-cymenene (8.95–10.86%) alongside 2,5-dimethoxy-p-cymene (2.92–3.54%). Late-stage harvests (H2 and H3) showed a more than three-fold increase in linalool (1.35% to 4.82%), enriching the oxygenated fraction and aroma quality. These results confirm that Mediterranean-grown yuzu maintains its aromatic identity while developing a high-yield regional profile, providing practical guidance for optimizing harvest timing across flavor, fragrance, and cosmetic applications.