Elucidation of the volatilome of packaged Spanish-style green olives of cv. Conservolea and Halkidiki using SPME-GC/MS

Spanish-style green olives are the most important trade preparation of table olives with great economic importance in the international market. As fermented product, olives are characterized by a wide variety of volatile compounds due to microbial metabolism, resulting in the development of the organoleptic characteristics of the final product and especially flavor. In the present study, the volatile profile of Conservolea and Halkidiki cultivars, processed as green olives by the Spanish method, was elucidated. Specifically, olives after fermentation were packaged in multi-laminated pouches and stored at room temperature for 12 months. Solid phase micro-extraction (SPME) was used for the isolation of volatile components, which were further determined by gas chromatography coupled to mass spectrometry (GC–MS). Eighty-nine compounds were identified, including several aldehydes, ketones, acids, terpenes, esters and alcohols. More specifically, the main volatile compounds of both cultivars were acetic acid, propanoic acid, ethanol, 2-butanol and 1-propanol, whereas several esters were found in high concentrations as well (ethyl acetate, ethyl propanoate, n-propyl acetate, propyl propanoate). However, there were some quantitative differences between the two varieties regarding some of the identified substances. Higher concentrations of 2-butanol were found in the Halkidiki cultivar, whereas the content of ethyl propanoate was higher in the Conservolea cultivar. Furthermore, differences in the quantities of some volatile compounds over time were observed. In particular, acetic acid, propanoic acid, ethanol, 1-propanol as well as all the aforementioned esters, showed a gradual increase in their concentration during storage.

Acknowledgement: This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH – CREATE – INNOVATE (project code: T1EDK-04110)