Abstract: Headspace solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to identify and analyze the volatile compounds of Vidal Blanc grapes cultivated on pergola or vertical trellis system. Heat map, partial least squares-discriminant analysis (PLS-DA), and aroma radar chart analyses were applied to explore the influence of different training systems on the aroma profile of Vidal Blanc grapes. The results showed that a total of 87 volatile compounds were identified. Regardless of training systems, higher alcohols and C6 compounds greatly contributed to the total content of volatile compounds in Vidal Blanc grapes. Terpene compounds accounted for a small fraction of the total volatile compounds in grapes grown on pergola, while they were the most abundant volatile compounds in those grown on vertical trellis. The odor activity value (OAV) was mainly contributed by higher alcohols, terpenes, C6 and C9 compounds. C9 compounds were the major aroma components in grapes from the pergola system, while terpene compounds were the major aroma components in grapes from the vertical trellis system. A total of 24 volatile compounds with OAV > 1 were identified. Most of the volatile compounds showed a gradual increase during the harvest period, and 18 volatile compounds were found to be more abundant in grapes from the vertical trellis system. The aroma radar chart showed that the most prominent aroma characteristics were grassy, floral, and fruity notes and the aroma profile of grapes from the vertical trellis system was better than that of grapes from the pergola system. To sum up, vertical trellis was a more training system than pergola for Vidal Blanc grape in Huanren county, Northeast China.

Key words: headspace solid phase microextraction; gas chromatography-mass spectrometry; pergola system; vertical trellis system; volatile compounds