Comprehensive metabolomic profiling of aroma-related volatiles in table grape cultivars across developmental stages

Abstract Aroma is a crucial determinant of consumer preference in both table grapes and wine production. While extensive research has been dedicated to characterizing aroma compounds in wine grapes, it is crucial to prioritize aroma profiling studies on table grapes, considering the increasing consumer demand for premium-quality fresh grapes. This study investigated the volatile organic compounds (VOCs) in nine table grape cultivars with distinct berry aromas, including newly developed cultivars in China, to identify key differential aroma contributors. A total of 44 VOCs were identified, with significant variation in ester and terpene compositions across cultivars. Among these, 21 odorants exhibited odor activity values greater than 1 and were classified into aromatic series categories. Muscat cultivars displayed dominant floral notes linked to high terpene levels, while the ‘Kyoho’ series showed pronounced fruity and sweet aromas due to elevated ester levels. Herbaceous cultivars were characterized by C6-derived green notes. Notably, the novel cultivar ‘Tiangong Liren’ (TGL) exhibited the highest total VOC content and aromatic series scores, forming a distinct cluster. Upset analysis identified five unique monoterpene odorants specific to this TGL. Developmental stage dynamics revealed that VOC differentiation was initiated during the intermediate Brix stage and peaked at harvest maturity, with geraniol serving as a key precursor. This study establishes a robust framework for aroma characterization in table grapes, providing actional insights for breeding programs and quality-driven practice to meet evolving market standards.