Characteristic free aromatic components of nine clones of spine grape (Vitis davidii Foex) from Zhongfang County (China)

Spine grape (Vitis davidii Foex) is a wild grape species in South China. However, it has not yet been effectively developed and utilized. To provide sufficient experimental evidence for the characteristic flavor of the spine grapes (V. davidii Foex), nine clones of the spine grape from Zhongfang County, Hunan Province, China, were evaluated for their aromatic components. In this study, several new compounds, including geranylacetone, mequinol, and eugenol were isolated from the spine grape, that have not been reported for other Vitis species. These compounds likely contribute to the characteristic flavor of the spine grape. (E,E)-2,4-hexadienal, which is not produced by Vitis vinifera, was found in the spine grape in large concentration. The results showed that C6 compounds are predominant aromatic components in various spine grape clones, accounting for 71% to 94% of the sum of aromatic compounds identified. (E)-2-hexenal was the predominant C6 compound, ranging from 814 ± 60 (Baiputao) to 3788 ± 74 (Xiangzhenzhu #2) μg/kg. Regarding terpenes and C13-norisoprenoids, the highest content of nerol, linalool, menthol, and β-ionone was present in Seputao grapes, while the highest content of β-damascenone was detected in Miputao #2. Benzyl alcohol was the most abundant shikimic acid derivative, and varied between 106 ± 6.9 and 522 ± 50 μg/kg among the different spine grape cultivars. For most aromatic compounds identified in this study, the content in Seputao was significantly higher than the other eight spine grape clones. This presents Seputao to a candidate for development of higher utilization value.