Preliminary results on the effect of cluster thinning on stilbene concentration and antioxidant capacity of Vitis vinifera L. "Barbera" wine.

Cluster thinning applied at veraison on Barbera grapevine variety reduced grape yield by 51.7% and titratable acidity by 9.6%, while increasing the soluble solids and pH by 8.2% and 2.6% respectively. Cluster thinning enhanced the trans-piceide and trans-resveratrol wine concentration over the control, ranging from 0.40 mg/L to 0.26 mg/L and from 1.41 mg/L to 0.98 mg/L respectively. The antioxidant activity of thinned vines were 50% higher than the control vines.