IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Influence of dehydration and maceration conditions on VOCs composition and olfactory profile of Moscato Bianco passito sweet wine

Influence of dehydration and maceration conditions on VOCs composition and olfactory profile of Moscato Bianco passito sweet wine

Abstract

Among the Vitis vinifera L. cv. Moscato, Moscato Bianco is the oldest and most cultivated one in Europe (1). According to the OIV Focus 2015, Italy is the country with the largest cultivated area of Moscato Bianco with about 12500 hectares (2), that is used to produce well-known wines (i.e., Moscato Passito in Piedmont, Moscato di Trani in Puglia, and Moscatello di Montalcino in Tuscany), mainly obtained from partially dehydrated grapes (1). Different dehydration techniques can strongly modify the chemical compounds of oenological interest, among which Volatile Organic Compounds (VOCs) (1) that are the main responsible for the varietal sensory character of the final wine.

The aims of the present research were to evaluate the effects of two different dehydration techniques (on vine; post-harvest) on the VOCs composition and odour profile of the corresponding Moscato sweet passito wines. Further, the introduction of a pre-fermentative cryomaceration step was also evaluated.
Moscato Bianco grapes, grown in Puglia (Italy), were used to obtain four wine samples: passito wines from grapes dehydrated on vine (oVD) and in post-harvest on plastic racks (pHD), vinified with skin maceration during the alcoholic fermentation (AF); the same two grapes were vinified with a pre-fermentative cryomaceration phase at 0°C for 4 days (oVD_pM and pHD_pM, respectively). VOCs and sensory profiles of the four wine samples were analysed by LL/GC-MS and descriptive sensory assessment (9 experienced and trained judges, 5 point numerical category scale). 

Results show that the different dehydration and maceration conditions significantly (ANOVA, p<0.05) influenced the volatile composition of the wines, allowing to obtain wines with different olfactory properties. Indeed, higher levels of some important terpenes (i.e., geranic acid, β-linalool, nerol, α-terpineol) as well as more intense floral odours were detected in oVD compared to pHD, showing intense honey and dehydrated fruits notes. This suggest that the on-vine dehydration is more preservative of varietal aromas, preventing the “sensory homologation” towards dehydrated notes. The introduction of the pre-fermentative cryomaceration step mostly affected VOCs related to the AF, namely esters, acids, and alcohols, but the floral character of oVD_pM was preserved. 

VOCs-odour and odour-odour correlations were tested by Person correlation (p<0.05): woody and honey descriptors were correlated (r=1.000) to each other, and to the same VOCs (ethyl vanillate, butyrolactone, furfural, 1-butanol, among others); the fruity character was positively correlated to esters, terpenes, and alcohols; dehydrated apricot and dried fig descriptors resulted strongly correlated (r>0.8) to acetoin.

References

1. Mencarelli & Tonutti (2013), Sweet, Reinforced and Fortified Wines: Grape Biochemistry, Technology and Vinification.
2. OIV (2015). Grapevine varieties’ area by country.

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

Pittari Elisabetta1, Napoletano Michele1, Moio Luigi1, Tarricone Luigi2 and Piombino Paola1

1Department of Agricultural Sciences (DiA), University of Naples Federico II, Italy
2CREA-VE, Council for Agricultural Research and Economics – Research Centre for Viticulture and Enology, Turi (BA), Italy

Contact the author

Keywords

Moscato Bianco, grapes dehydration, pre-fermentative cryomaceration, sweet wines, volatiles

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Mesoclimate impact on Tannat in the Atlantic terroir of Uruguay

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.

Deconstructing the soil component of terroir: from controversy to consensus

Wine terroir describes the collectively recognized relation between a geographical area and the distinctive organoleptic characteristics of the wines produced in it. The overriding objective in terroir studies is therefore to provide scientific proof relating the properties of terroir components to wine quality and typicity. In scientific circles, the role of climate (macro-, meso- and micro-) on grape and wine characteristics is well documented and accepted as the most critical. Moreover, there has been increasing interest in recent years about new elements with possible importance in shaping wine terroir like berry/leaf/soil microbiology or even aromatic plants in proximity to the vineyard conferring flavors to the grapes. However, the actual effect of these factors is also dependent on complex interactions with plant material (variety/clone, rootstock, vine age) and with human factors.
The contribution of soil, although a fundamental component of terroir and extremely popular among wine enthusiasts, remains a much-debated issue among researchers. The role of geology is probably the one mostly associated by consumers with the notion of terroir with different parent rocks considered to give birth to different wine styles. However, the relationship between wine properties and the underlying parent material raises a lot of controversy especially regarding the actual existence of rock-derived flavors in the wine (e.g. minerality). As far as the actual soil properties are concerned, the effect of soil physical properties is generally regarded as the most significant (e.g sandy soils being associated with lighter wines while those on clay with colored and tannic ones) mostly through control of water availability which ultimately modifies berry ripening conditions either directly by triggering biosynthetic pathways, or indirectly by altering vigor and yield components. The role of soil chemistry seems to be weakly associated to wine sensory characteristic, although N, K, S and Ca, but also soil pH, are often considered important in the overall soil effect.
Recently, in the light of evidence provided by precision agriculture studies reporting a high variability of vineyard soils, the spatial scale should also be taken into consideration in the evaluation of the soil effects on wines. While it is accepted that soil effects become more significant than climate on a local level, it is not clear whether these micro-variations of vineyard soils are determining in the terroir effect. Moreover, as terroir is not a set of only natural factors, the magnitude of the contribution of human-related factors (irrigation, fertilization, soil management) to the soil effect still remains ambiguous. Lastly, a major shortcoming of the majority of works about soil effects on wine characteristics is the absence of connection with actual vine physiological processes since all soil effects on grape and wine chemistry and sensorial properties are ultimately mediated through vine responses.
This article attempts to breakdown the main soil attributes involved in the terroir effect to suggest an improved understanding about soil’s true contribution to wine sensory characteristics. It is proposed that soil parameters per se are not as significant determining factors in the terroir effect but rather their mutual interactions as well as with other natural and human factors included in the terroir concept. Consequently, similarly to bioclimatic indices, composite soil indices (i.e. soil depth, water holding capacity, fertility, temperature etc), incorporating multiple soil parameters, might provide a more accurate and quantifiable means to assess the relative weight of the soil component in the terroir effect.

Analysis of Cabernet Sauvignon and Aglianico winegrape (V. vinifera L.) responses to different pedo-climatic environments in southern Italy

Water deficit is one of the most important effects of climate change able to affect agricultural sectors. In general, it determines a reduction in biomass production, and for some plants, as in the case of grapevine, it can endorse fruit quality. The monitoring and management of plant water stress in the vineyard

First step in the preparation of a soil map of the Protected Designation of Origin Valdepeñas (Central, Spain)

This work is a first step to make a map of vineyard soils. The characterization of the soils of the Protected Designation of Origin (D.P.O.) Valdepeñas will allow to group the studied profiles according to their physico-chemical characteristics and the concentrations of most relevant chemical elements. 90 soil profiles were analysed throughout the territory and the soils were sampled and described according to FAO (2006) and classified according to and Soil Taxonomy (2014). All samples were air dried, sieved and some physico-chemical parameters were determined following standard protocols. Also, major and trace elements were analysed by X-ray fluorescence. The statistically study was made using the SPSS program. Trend maps were made using the ArcGIS program. The studied soils have the following average properties: pH, 8.3; electrical conductivity, 0,20 dS/m (low); clay, 18.8% (medium) and CaCO3, 17.1% (high). In the study for the major elements. The major elements of these soils are Si, followed by Ca and Al, with an average content of 203.7 g/kg, 105.5 g/kg and 74.0 g/kg respectively. On the other hand, 27 trace elements have been studied. Of all of them, it can be highlighted the average values of Ba (361.8 mg/kg), Sr (129.3 mg/kg), Rb (83.4 mg/kg), V (74.2 mg/kg) and Ce (70.6 mg/kg). Ba, V and Ce values are higher and the values of Sr and Rb are lower to those found in the literature. The discriminant analysis shows a percentage of grouping of 91%. The content of chemical elements together with the physico-chemical characteristics allows grouping the soils in 4 group according to their order in the classification to Soil Taxonomy; due to the importance of the Calcisols in Castilla-La Mancha, it has been decided to establish them as their own group even if they do not appear in Soil Taxonomy classification.

Phenological characterization of a wide range of Vitis Vinifera varieties

In order to study the impact of climate change on Bordeaux grape varieties and to assess the adaptation capacities of candidates to the grape varieties of this wine region to the new climatic conditions, an experimental block design composed of 52 grape varieties was set up in 2009 at the INRAE Bordeaux Aquitaine center. Among the many parameters studied, the three main phenological stages of the vine (budburst, flowering and veraison) have been closely monitored since 2012. Observations for each year, stage and variety were carried out on four independent replicates. Precocity indices have been calculated from the data obtained over the 2012-2021 period (Barbeau et al. 1998). This work allowed to group the phenological behaviour of the grapevine varieties, not only based on the timing of the subsequent developmental stages, but also on the overall precocity of the cycle and the total length of the cycle between budburst and veraison. Results regarding the variability observed among the different grape varieties for these phenological stages are presented as heat maps.