Abstract:

The taxifolin contents of grape skins, seeds and pulps from Vitis davidii, a wild grape species originating in China,
and wines from individual varieties of V. davidii and Vitis vinifera were determined using high performance liquid
chromatography-tandem mass spectrometry (HPLC-MS/MS). Taxifolin content was the highest in the grape skin of
V. davidii, which was (2.44 ± 0.18) and (2.03 ± 0.14) mg/kg fresh weight (FW) in two varieties with colored and white
skin, respectively. The taxifolin contents of the seeds of these two varieties were (1.66 ± 0.13) and (1.38 ± 0.12) mg/kg,
respectively. Taxifolin content was the lowest in pulps for both varieties, which was (0.36 ± 0.02) and (0.25 ± 0.02) mg/kg,
respectively. No significant differences in taxifolin content were found for different parts of grape berries between the two
varieties of V. davidii. However, Taxifolin content in the skin of V. vinifera L. cv. Pinot Noir was significantly higher than
in the skin of V. vinifera L. cv. Pinot Blanc, suggesting that the taxifolin content is not correlated with the skin color of
grape berries. Since a different vinification was used for the white grape variety, which kept the taxifolin in skins and seeds
from entering the wine, the taxifolin content of wines from the white variety was only 20% as compared to that of
wines from the colored variety for both V. davidii and V. vinifera. Taxifolin content in wine was somewhat lower than
in grape berry skin, due to the greater extraction ability of methanol for taxifolin in the skin, as compared to that of
ethanol produced in wine.

Key words: Vitis davidii, taxifolin, HPLC-MS/MS, wine