CHANGES IN THE ODOR-ACTIVE COMPOUNDS IN VITIS-LABRUSCANA CV CONCORD DURING GROWTH AND DEVELOPMENT

Three compounds important to the characteristic flavor (American character) of Vitis labruscana Bailey cv. Concord grapes (o-aminoacetophenone, methylfuraneol, and methyl anthranilate) were quantified in both berries and leaves before and after veraison (the onset of color formation in fruit). beta-Damascenone, a compound important to the flavor of most grapes, and its hydrolyzable precursors (including glycosides) were also measured. The compounds with American character were detected only after veraison and only in the berries, where they increased rapidly after veraison. However, beta-damascenone and its hydrolyzable precursors were detected in the leaf and berry tissue during the entire season. Furthermore, both free and bound beta-damascenone increased in the berries after veraison, while only the bound forms increased in the leaves.