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…

STATISTICAL COMPARISON OF GROWTH PARAMETERS OF NINE BIOPROTECTION STRAINS IMPLEMENTED ON ARTIFICIALLY CONTAMINATED SYNTHETIC MUST

In recent years, consumer demand for products without chemical additives increased, becoming a priority for the wine sector. SO₂ is widely used for its multiple properties including antiseptics, antioxidants and antioxidasics and the strategy of bioprotection in winemaking represents now an alternative to this chemical additive. In oenology, results have highlighted the interest of bioprotection to limit the development of microorganisms like Hanseniaspora uvarum and thus reduce the doses of sulphite. Indeed, this species is considered because of its acetic acid and methyl butyl acetate production, the latter can cover the varietal character of wines.
Read More

IMPACT OF MUST NITROGEN DEFICIENCY ON WHITE WINE COMPOSITION DEPENDING ON GRAPE VARIETY

Nitrogen (N) nutrition of the vineyard strongly influences the must and the wine compositions. Several chemical markers present in wine (i.e., proline, succinic acid, higher alcohols and phenolic compounds) have been proposed for the cultivar Chasselas, as indicators of N deficiency in the grape must at harvest [1]. Grape genetics potentially influences the impact of N deficiency on grape composition, as well as on the concentration of potential indicators in the wine. The goal of this study was to evaluate if the che- mical markers found in Chasselas wine can be extended for other white wines to indicate N deficiency in the grape must.

Read More

THE POTENTIAL USE OF SOLUBLE POLYSACCHARIDES TO PREVENT THE OXIDATION OF ROSÉ WINES

Lately, rosé wine is rapidly increasing its popularity worldwide. Short-time macerations with the red skin of the grapes cause the partial extraction of anthocyanins, which are responsible for the pinki-sh-salmon hue of rosé wines. However, the low quantity of tannins (antioxidants) and richness in phenolic acids, which can be easily oxidized into yellowish pigments, tend to predispose rosé wines to an undesirable browning. Although the use of SO₂ for the prevention of oxidation is highly extended, this practice is expected to be reduced. Therefore, the search for alternative oenological adjuvants that prevent the oxidation and browning of rosé wines is highly desired.

Read More

NEW INSIGHTS INTO VOLATILE SULPHUR COMPOUNDS SCALPING ON MICROAGGLOMERATED WINE CLOSURES

The evolution of wine during bottle ageing has been of great interest to ensure consistent quality over time. While the role of wine closures on the amount of oxygen is well-known [1], closures could also play other roles such as the scalping phenomenon of flavour compounds. Flavour scalping has been described as the sorption of flavour compounds by the packaging material, which could result in losses of flavour intensity. It has been reported in the literature that volatile sulphur compounds (VSC) can be scalped on wine closures depending on the type of closure (traditional and agglomerated cork, screw-cap, synthetic [2]).

Read More

DETERMINATION OF MINERAL COMPOSITION IN CV. TERAN (VITIS VINIFERA L.) RED WINE AFFECTED BY PRE-FERMENTATIVE MASH COOLING, HEATING, SAIGNÉE TECHNIQUE AND PROLONGED POST-FERMENTATIVE MACERATIONS

This study aimed to determine mineral composition in red wine obtained from cv. Teran (Vitis vinifera L.), autochtonous Croatian grape variety. Six different vinification treatments, including the control treatment (7-day standard maceration), were performed to study the effects of: 48-hour pre-fermentative mash cooling (8 °C) followed by prolonged post-fermentative maceration of 13 days (C15), 28 days (C30), and saignée technique (juice runoff) proceeded with prolonged post-fermentative maceration of 13 days (CS15); and effect of 48-hour heating (50 °C) followed by prolonged post-fermentative maceration of 13 days (H15) and 28 days (H30) on macro- and microelements in wine.

Read More