Effect of Harvesting Time on Volatile Compounds Composition of Bergamot (Citrus × Bergamia) Essential Oil

Bergamot (Citrus × bergamia) is mainly cultivated in Calabria area (Italy) for its essential oil that is widely used in cosmetics, food and medicine. The harvest season (November to February) affects the quality of essential oil, consequently the aim of our study was to evaluate the composition of volatile fractions at different harvesting stages. Two different cultivars, Femminello and Fantastico, were collected in November, December and January and their volatile compounds composition was determined by SPME GC/MS. Fourty‐two compounds were identified. Monoterpenes were the preponderant group; limonene was the most representative compound with similar concentrations in the varieties and at the three harvesting times. β‐Ocimene, β‐mircene and α‐terpinene showed higher concentration in Femminello than Fantastico, while trans‐α‐bergamotene, α‐pinene and citronellal were mostly concentrated in Fantastico. The concentration of β‐pinene in Fantastico and Femminello was higher in December and January, respectively, and γ‐terpinene concentration was higher in Femminello in November and January and in Fantastico in December. Linalool was the most preponderant monoterpene alcohol with a significantly higher concentration in Femminello than in Fantastico, but without significant differences during ripening. cis‐γ‐Bisabolene was the most preponderant sesquiterpene; it was more concentrated in Fantastico than in Femminello and showed a significantly higher concentration in December and January than in November. Linalyl and neryl acetate were the most abundant esters, with a significantly higher concentration in Fantastico. Fantastico seems to be the variety that produces higher volatile organic compounds in essential oil; moreover, the volatile compound concentration was higher at the second and third harvest time. The ripening stage significantly modify bergamot oil volatile composition; monoterpenes and aldehydes showed a significant increase during ripening, balanced by a decrease of monoterpene alcohols and esters; sesquiterpenes, instead, showed an unstable trend during ripening.