Aroma potential of three autochthonous grapevine varieties from Tunisia

Aims : The aim of the present work is to characterize the aromatic profiles of three Tunisian autochthonous grapevine ( Vitis vinifera L.) varieties (Asli, Beldi and Ferrani). Methods and results : The GC-MS analysis of the autochthonous grapevine varieties studied allowed identifying 38 volatile compounds in the free fraction and 36 glycosidically bound aroma compounds. Volatile C6 compounds were typical for the studied varieties especially for Asli variety. The analysis of the liberated aglycones through enzymatic hydrolysis show that a-terpineol and cis linalool oxide pyran that did not appear as free aroma compounds were found with significantly highest concentration in Asli grape juice. Also, 3-oxo-α-ionol and 3-hydroxy-7,8-dihydro-β-ionol were found only under their glycosidically bound forms with significantly higher concentrations in Asli and Ferrani than in Beldi grape juices. Conclusion : The results obtained in the present work show qualitative and quantitative differences in the aroma profiles among the studied varieties. However, non-terpenyl compounds were the most abundant aroma substances in the three studied varieties. Significance and impact of the study : The present work characterize, for the first time, the aromatic profiles of three Tunisian autochthonous grapevine varieties (Asli, Beldi and Ferrani) and constitutes a major contribution to the aroma chemistry of these three grape varieties.