Volatile Compound Profile as a Biomarker of the Ripening Stage of Cornelian Cherry Fruits

This study aims to evaluate, for the first time, the profile of volatile compounds (VCs) at four different ripening stages of cornelian cherry (Cornus mas L. cultivar ‘Bolestraszycki’) fruits: unripe (green), semi-ripe (pale orange and light red), and fully ripe (dark red), to indicate specific volatile markers describing fruit ripening stages. The evolution of aroma VCs was investigated using gas chromatography/mass spectrometry (GC/MS) combined with headspace-SPME extraction. Aldehydes and alcohols dominated the VC profile of cornelian cherry fruits, accounting for 18.2–54.7% and 20.0–45.9%, respectively. The maturation process caused a significant decrease in aldehyde relative amounts (a 7-fold reduction in hexanal) and a simultaneous increase in alcohols (relatively higher amounts of ethanol, butanol, and the presence of hexanol). High levels of hexanal, 2-hexenal (E), pentanol, 1-octen-3-ol, 6-methyl-5-hepten-2-one, camphor, kaurene, cadinene, pentane, and dimethyl sulfide, along with the absence of many esters and alcohols, may serve as volatile markers of unripe fruits. Conversely, high levels of ethanol, butanol, and hexanol, along with numerous esters dominated by ethyl acetate and increased levels of acetic acid, were specific to fully ripe fruits. In conclusion, the presence or relative amount of certain VCs may serve as biomarkers of ripening stages of cornelian cherry fruits.