Odour-active compounds of Citrus deliciosa Tenore var. Caí essential oils detected by gas chromatography-mass spectrometry and gas chromatography-olfactometry

Context: Mandarins are a complex taxonomic group including different species, cultivars and hybrids growing around the world being fruits greatly appreciated by the consumers. Citrus deliciosa Tenore var. Caí originates from Rio Grande do Sul State (Brazil) and the fruit is characterised by its pleasant properties, especially its aroma. Aims: To evaluate the C. deliciosa cold-pressed essential oils, classified as “green”, “yellow” and “red” according to fruit maturity, and the one produced by distillation by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). Methods: The essential oils aromatic quality was evaluated by GC-O through a panel of trained judges. The identification of the volatile compounds was performed by GC-MS and their quantification by GC-FID. Results: The chemical composition of the three types of cold-pressed essential oils was very similar. However, the distilled oil presented a higher concentration of oxygenated monoterpenes (mainly α-terpineol, 4-terpineol and sabinene hydrates). Herbaceous and floral aromatic notes were able to describe the “green” oil, while for the distilled oil wood and unpleasant notes were perceived. Conclusions: The cold-pressed oils did not show nor chemical, or aromatic differences, by the fruit maturity. The distilled oil was characterized by aromatic nuances making the oil less appreciated (inferior quality) than the cold-pressed oil. Probably as consequence of artifacts formation during the distillation process.