Volatomics of 'Cabernet Sauvignon' grapes and wines under the fan training system revealed the nexus of microclimate and volatile compounds.

ABSTRACT

The cluster-zone of the fan training system with multiple trunks (F-MT) distribute >1.5 m vertically and 1.0 m horizontally, which leads to microclimate heterogeneity around clusters. In the current study, clusters were divided into eight spatial positions according to the cluster growing height and light conditions, and the aroma profiles of grapes and wines were evaluated by HS-SPME-GC-MS. Results showed that the microclimate varied in different spatial positions. Light exposure promotes the accumulation of terpenes and C13-norisoprenoids, while inhibiting C6/C9 compounds in grape berries. Zone 2 wine presented the highest global aroma concentration. Floral and fruity were the main aromas in F-MT wines, but the herbaceous was more prominent in lower-position wines. C6/C9 compounds in grapes negatively correlated with terpenes and C13-norisoprenoids in wines. In conclusion, the aroma profiles of grapes and wines varied from different cluster positions, and graded harvesting will be helpful to produce quality wines.