Effect of early defoliation on volatile composition and sensory properties of aglianico red wines

Abstract

AIM: The aim of this work was to study the influence of early defoliation in the vineyard on Aglianico wines quality from Apulia region (Italy). Early defoliation was conducted in commercial Aglianico (Vitis vinifera L.) vineyards situated in Apulia region in Italy during the 2018 season.

METHODS: Three defoliation treatments were carried out in the vineyard: DN, where 100% of fruit-zone leaves removed from the North canopy side; DS, 100% where of fruit-zone leaves were removed, from the South canopy side DNS, where 100% removal of fruit-zone leaves on both the North and the South side of the canopy. A control (CT), where all basal leaves were retained in each shoot, also was performed. Instrumental (GC-MS) and sensory analysis (QDA) were used to evaluate the treatment effect on volatile composition and sensory descriptors of wines.

RESULTS: Results showed the effect of early defoliation treatment on 37.8 % (14 out 37 compounds) of the volatiles identified and quantified. Defoliation treatments led to wines with the significant highest concentrations of 13 volatile compounds. Aglianico wines from early defoliation in north side (DN) increase the concentration of nine volatile compounds respect to south side (DS) and both sides (DNS). In sensory analysis Aglianico wines were defined by sixteen sensory attributes with GM > 30 %, where the highest values were reached for defoliation treatments vs control. Moreover, ten sensory descriptors (> 30 % GM) reached the highest value for DNS treatment. The highest value for total quality was also reached by DNS treatment. In conclusion defoliation treatments increased the volatile concentration of Aglianico wines.

CONCLUSIONS

In conclusion defoliation treatments increased the volatile concentration of Aglianico wines from Apulia region (Italy).