terclim by ICS banner
IVES 9 IVES Conference Series 9 EFFECTS OF LEAF REMOVAL AT DIFFERENT BUNCHES PHENOLOGICAL STAGES ON FREE AND GLYCOCONJUGATE AROMAS OF SKINS AND PULPS OF TWO ITALIAN RED GRAPES

EFFECTS OF LEAF REMOVAL AT DIFFERENT BUNCHES PHENOLOGICAL STAGES ON FREE AND GLYCOCONJUGATE AROMAS OF SKINS AND PULPS OF TWO ITALIAN RED GRAPES

Abstract

Canopy-management practices are applied in viticulture to improve berries composition and quality, having a great impact on primary and secondary grape metabolism. Among these techniques, cluster zone leaf removal (defoliation) is widely used to manage air circulation, temperature and light radiation of grape bunches and close environment. Since volatiles are quantitatively and qualitatively influenced by the degree of fruit ripeness, the level of solar exposure, and the thermal environment in which grapes ripen, leaf removal has been shown to affect volatile composition of grape berries [1].

The aim of this research was to assess the impact of vine defoliation on free and glycosylated VOCs (Volatile Organic Compounds) of two Italian red grapes: Nebbiolo (neutral) and Aleatico (semi-aromatic). Defoliation was performed at fruit set phenological stage for Aleatico grapevines, and for Nebbiolo also at berries touch.

Solid Phase Extraction/Gas Chromatography–Mass Spectrometry (SPE/GC-MS) was carried out to ana-lyse free and glycoconjugates VOCs isolated from skins and pulps as separate portions of the berries [2].

The results showed that defoliation had an almost negligible effect on free and glycosylated volatiles of Aleatico grapes, thus suggesting that defoliation at fruit set did not change the volatile composition of this grape variety. A different behaviour was observed for Nebbiolo grapes, on both free and bound VOCs, with a greater impact on the first. Indeed, all the 30 free VOCs identified were significantly (ANOVA; p<0.05) affected by defoliation and by the time at which it was carried out, with a greater influence on the skin components. Early defoliation at fruit set did not favour the accumulation of free VOCs in Nebbiolo skins, significantly reducing the content of several VOCs, such as n-butyl acetate, terpenes (α-terpineol, and nerol) and aldehydes (hexanal, and 2-hexanal). On the other hand, late defoliation performed at berries touch, reduced n-butyl acetate, but increased alcohols content (i.e., 3-methyl-1-butanol, 1-pentanol, 2-ethyl-1-hexanol, benzyl and phenylethyl alcohols), nerol, aldehydes (i.e., 2-hexanal), and vanillin.

Results suggest that the effects of defoliation at fruit set on the VOCs pattern is cultivar dependent and almost ineffective on Aleatico grapes. Moreover, early defoliation at fruit-set seems stressful for Neb-biolo grapes and its odorous and potentially secondary metabolites. These results can be useful to improve canopy and winemaking precision practices.

 

1. Poni et al., 2006. DOI: 10.5344/ajev.2006.57.4.397
2. Piombino et al., 2022. DOI: 10.1111/ajgw.12521

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Paola Piombino¹, Elisabetta Pittari¹, Alessandro Genovese², Andrea Bellincontro³, Osvaldo Failla⁴, Luigi Moio1, Fabio Mencarelli⁵

1. Department of Agricultural Sciences, Division of Vine and Wine Sciences, University of Naples Federico II, Avellino 83100, Italy
2. Department of Agricultural Sciences, Division of Food Science and Technology, University of Naples Federico II, Portici (NA), 80055, Italy
3. DIBAF, University of Tuscia, Via De Lellis, 01100 Viterbo, Italy
4. Department of Agricultural and Environmental Sciences, University of Milan, 20133 Milano, Italy
5. Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy

Contact the author*

Keywords

defoliation, secondary metabolites, aromas

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

INVESTIGATING TERROIR TYPICITY: A COMPREHENSIVE STUDY BASED ON THE AROMATIC AND SENSORIAL PROFILES OF RED WINES FROM CORBIÈRES APPELLATION

Volatile compounds play a significant role on the organoleptic properties defining wines quality. This particular role was exploited in several studies with the aim to differentiate wines from a more or less extensive production area, according to their sensory profile [1], as well as their chemical composition [2,3] (Di Paola-Naranjo et al., 2011; Kustos et al., 2020). Indeed, since aroma compounds development in grapes depends primarily on the environmental conditions of the vines and grapes (soil and climate), it is conceivable that these parameters craft the aromatic signature of the wine produced, in relation to its origin (Van Leeuwen et al., 2020). In this work, a general study on the aromatic and sensorial profile of wines produced in five sub-regions of the Corbières denomination, a renowned red grape varieties viticultural region in South France, was reported.
Read More

AROMA ASSESSMENT OF COMMERCIAL SFORZATO DI VALTELLINA WINES BYINSTRUMENTAL AND SENSORY METHODOLOGIES

Sforzato di Valtellina DOCG is a special dry red wine produced from partially dehydrated Nebbiolo wine-grapes growing in the Rhaetian Alps valley of Valtellina (Lombardy, Italy). Valtellina terraced vineyards are located at an altitude of 350–800 m according to ‘heroic’ viticulture on steep slopes. The harvested grape bunches are naturally dehydrated indoors, where a slow and continuous withering occurs (about 20% w/w of weight loss), until at least 1st December when the grapes reach the desired sugar content and can be processed following a normal winemaking with maceration.

Read More

CHARACTERIZATION OF THE VOLATILE COMPOUNDS PROFILE OF COMMERCIAL GRAPPAS OBTAINED FROM THE POMACE OF AMARONE WINES

Grappa is a traditional Italian alcoholic beverage, with an alcohol content generally between 40-60% vol., obtained from the distillation of grape pomace used for the production of wine. Grappa are often aged in wooden barrels. There are various types of grappa: young, aromatic, aged, extra-aged depending on whether the distillate comes from aromatic vines or is aged in wooden barrels for shorter or longer periods. There is also flavored grappa if herbs, fruit or roots are added. All this makes it an extremely heterogeneous product both from an organoleptic and compositional point of view.

Read More

Rootstock mediated responses of grapevine (Vitis vinifera L.) metabolism and physiology to combined water deficit and salinity stress in Syrah grafts

Water deficit and salinity are increasingly affecting the viticulture and wine industry. These two stresses are intimately related; understanding the physiological and metabolic responses of grapevines to water deficit, salinity and combined stress is critical for developing strategies to mitigate the nega- tive impacts of these stresses on wine grape production. These strategies can include selecting more tolerant grapevine cultivars and graft combinations, improving irrigation management, and using soil amendments to reduce the effects of salinity. For this purpose, understanding the response of grape- vine metabolism to altered water balance and salinity is of pivotal importance.

Read More

NEW PLANT BIOPOLYMERS FOR THE COLLOIDAL STABILITY OF THE COLORING MATTER OF RED WINES

The color as well as the “clarity” of red wines are ones of the qualities required by the consumers. Red wines must have colloidal stability from its bottling to its consumption. The supplementation of red wines with additives, and especially Acacia senegal gum, contributes to its organoleptic properties such as the colloidal stabilization of the coloring matter. In a global perspective of limitation of additives in the field of enology, one of the objectives is notably (i) to reduce the use of additives in wines, by their number and/or their quantity, and (ii) to favor the use of natural additives while preserving the organoleptic and sensory qualities of wines.

Read More