Effect of leaf removal and ultraviolet radiation on the composition and sensory perception ofVitis vinifera L. cv. Sauvignon Blanc wine

Clonal differences and impact of defoliation on Sauvignon blanc (Vitis vinifera L.) wines: a chemical and sensory investigation

“…Other minor groups of esters can act synergistically with other volatiles in wines by enhancing or masking specific sensory attributes . Nevertheless, even though esters are undisputedly yeast‐derived aromatic compounds and varietal thiols are released during fermentation from their non‐odorous precursors, their concentrations and profiles can be altered in the vineyard by modifying the grape nitrogen status, the amino acids profile and the lipid composition …”

“…Increased light penetration in the bunch zone early in grape development (before veraison) is of utmost importance for decreasing the IBMP and IPMP concentrations in grapes at harvest and the effect of temperature on methoxypyrazines concentrations cannot be overlooked . A recent study on Sauvignon blanc suggested modifications in wine chemical and sensory composition when grapes were exposed to different light environment achieved either by defoliation or reduction of UV light …”

The impact of canopy managements on grape and wine composition of cv. ‘Istrian Malvasia’ (Vitis vinifera L.)

“…Vineyard practices certainly affect the synthesis and contents of phenolic compounds in grapes and wines, but factors such as variety, plant diseases, grape maturity and seasonal climatic conditions must also be considered . The different precipitation rates and the possible resulting plant stress might have influenced the phenolics in the berry skins, especially the contents of individual and total HCA, irrespective of treatment, especially taking into consideration the water supply at the time of berry growth, i.e.…”

“…Consequently, lower titratable acidity but higher soluble solids and pH are usually obtained in comparison with non‐defoliated vines . Furthermore, noticeable freshness, higher alcohol content and improved flavour could be the main characteristics of wine obtained after leaf removal, as reported by Suklje et al in the case of ‘Sauvignon Blanc’ (growth stage E‐L 29). In a cluster zone defoliation study on ‘Istrian Malvasia’, Bubola and Persuric did not find any significant differences in yield, which reached 3.51 kg per vine after post‐bloom leaf removal.…”

“…Removing basal and fully functional leaves at pre‐bloom reduces the carbohydrate supply to the flowers compared with non‐defoliated vines, leading to a reduction in fruit set . Consequently, lower titratable acidity but higher soluble solids and pH are usually obtained in comparison with non‐defoliated vines . Furthermore, noticeable freshness, higher alcohol content and improved flavour could be the main characteristics of wine obtained after leaf removal, as reported by Suklje et al in the case of ‘Sauvignon Blanc’ (growth stage E‐L 29).…”