OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 Aroma chemical profiles characterization of wines produced with moristel grapes harvested at different time points

Aroma chemical profiles characterization of wines produced with moristel grapes harvested at different time points

Abstract

The wine aroma is constituted by hundred of volatile chemical compounds that depend on many viticultural and oenological factors. One of the most important factors that will unequivocally affect the final wine pro-perties is the grape maturity level. Grape ripening is an extremely complex process, in which the metabolites and precursors concentrations change significantly with time. However, the knowledge of how grape ripe-ning affects wine aroma composition is still quite limited. Nowadays, wineries measure parameters such as sugar, pH, acidity and colorimetric tests to evaluate the degree of maturity of the vintage and decide the harvest data, but these analysis do not take into consideration the aromatic potential of the grape. The objective of the present work is to understand the differences in the aroma chemical profile of Moristel wines from different vineyards harvested at different time points. So, three different vineyards of Moris-tel grape variety in D.O. Somontano were selected, in two consecutive vintages: two in 2016 and one in 2017. Each block was harvested at different time points followed by microvinifications applying the same fermentation protocol. All of them have been elaborated in triplicated. This was assessed by the analysis of major aroma compounds (GC-FID), trace aroma compounds (GC-MS), methoxypyrazines (TD-GCxGC-MS), polyfunctionalmercaptans (SPE GC-MS), volatile sulfur compounds (BR-VSCs) and total acetaldehyde (HPLC-UV/VIS). The most important result is that the grapes harvested at 42 days postveraison, that is the “green” ones, pro-duce wines with high concentration of acetaldehyde and low IPT. Hence, low concentration of polyphenols facilitate the accumulation of this compound. Another reason for these acetaldehyde high concentrations could be problems associated with the lack of reduction factors (NADH or NADPH). This fact is also corroborated with the decreases of branched acid / fusel alcohol and branched ester/fu-sel alcohol ratios during the maturity. These facts can have very important sensory repercussion, the acetaldehyde and fusel alcohol are components of aroma buffer.

Finally, the evolution of certain maturity markers (c-3-hexenol, Y-nonalactona, rotundone) has been also observed, but these target compounds, by themselves, do not seem to have great sensory relevance in the final wines. This study has help to elucidate how grape maturity state contributes to final Moristel wine aroma profile and possible self-life.

Acknowledgements

This work has been funded by the Spanish MINECO (Project AGL2014-59840, RTC 2015-3379 and RTC-2016-4935-2) and partly co-funded by the European Union (FEDER). I.A. has re-ceived a grant from the Spanish FPU programs. Funding from D.G.A. (T53) and Fondo Social Europeo is acknowledged.

DOI:

Publication date: June 9, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Ignacio Arias, Sara Ferrero-del-Teso, María Pilar Sáenz-Navajas, Purificación Fernández-Zurbano,Blanca Lacau, Jesús Astraín, Cristina Barónv Vicente Ferreira, Ana Escudero

Instituto de Ciencias de la Vid y el Vino (ICVV) (Universidad de La Rioja-CSIC-Gobierno de La Rioja), Carre-tera de Burgos Km. 6, Finca La Grajera, 26007 Logroño, La Rioja, Spain
Laboratorio de análisis del aroma y enología (LAAE). Department of Analytical Chemistry, Universidad de Zaragoza, Instituto Agroalimentario de Aragón (IA2) (UNIZAR-CITA). Calle Pedro Cerbuna, 12, 50009 Zaragoza

Contact the author

Keywords

Wine aroma, maturity, acetaldehyde, reduction factors

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Upscaling the integrated terroir zoning through digital soil mapping: a case study in the Designation of Origin Campo de Borja

homogeneous zones by intersecting several partial zonings of major factors that influence vineyard growth. Each of them follows specific process from their corresponding disciplines. Soil zoning specifically refers to a Soil Resource Inventory map that has traditionally been generated by conventional soil mapping methods. These methods have shortcomings in reaching fine cartographic and categorical details and involve significant expenses, which undermines their applicability. A new framework named Digital Soil Mapping has introduced quantitative models by statistical techniques to establish soil-landscape relationships and is able to provide intensive scale cartography.

In the present study, a microzoning at 1:10.000 scale is generated from an initial zoning, where the conventional soil map with polytaxic map units is replaced by a new one from digital techniques that disaggregates them. The comparison between the zonings considers a quantitative evaluation of capability for each Homogeneous Terroir Unit by means of the Viticultural Quality Index and its categorization based on its distribution by map. The spatial intersection of both maps gives rise to a confusion matrix in which the flows of class variations after the substitution are assessed.

The results show a five-fold increase in the number of Homogeneous Terroir Units identified and a larger differentiation among them, evidenced by a wider range in the capability index distribution. Both elements are accompanied by an increase in the detection of areas of higher potential within previously undervalued uniform zones.These features are a direct effect of the improvements brought by Digital Soil Mapping techniques and would verify the advantages of their implementation in the Integrated Terroir zoning. Eventually, such new highly detailed terroir units would benefit precision viticulture and sustainable management practices.

Climate, Viticulture, and Wine … my how things have changed!

The planet is warmer than at any time in our recorded past and increasing greenhouse emissions and persistence in the climate system means that continued warming is highly likely. Climate change has already altered the basic framework of growing grapes for wine production worldwide and will likely continue to do so for years to come. The wine sector can continue to play an important role in leading the agricultural sector in addressing climate change. From developing on…

Effect of one-year cover crop and arbuscular mycorrhiza inocululation in the microbial soil community of a vineyard

The microbial composition of the soil is an important factor to consider in viticulture, since its influence on the “terroir” and on the organoleptic properties of the wine have been demonstrated. Different agronomic techniques have the potential to modify the composition and functionality of the soil microbial community. Maintaining green covers is known to increase soil microbial diversity. The direct application of inoculum of beneficial microorganisms to the soil has also been used to increase their abundance. However, the environmental conditions of each site seem to have a determining weight in the result of these practices. In this study, we compared the effect on the microbial community of a cover crop with legumes in autumn and the inoculation of grapevines with commercial inoculum bases on Rhizophagus irregularis and Funeliformis mosseae in the previous spring. The study has been carried out in a vineyard in Binissalem, Mallorca, Spain. After applying the treatments, we will analyze the soil microbial communities using the data obtained from Illumina amplification of soil DNA from the 16S and ITS regions to analyze bacteria and fungi community, respectively. In addition, we will record the physicochemical characteristics of the soil at each sampling point. The result showed that agronomic management, in the short term, has less influence than soil characteristics on the composition of the soil microbiome. With these results, we can conclude that in a vineyard, agricultural techniques should focus on improving the characteristics of the soil to improve the biodiversity of the soil microbiota.

A better understanding of the climate effect on anthocyanin accumulation in grapes using a machine learning approach

The current climate changes are directly threatening the balance of the vineyard at harvest time. The maturation period of the grapes is shifted to the middle of the summer, at a time when radiation and air temperature are at their maximum. In this context, the implementation of corrective practices becomes problematic. Unfortunately, our knowledge of the climate effect on the quality of different grape varieties remains very incomplete to guide these choices. During the Innovine project, original experiments were carried out on Syrah to study the combined effects of normal or high air temperature and varying degrees of exposure of the berries to the sun. Berries subjected to these different conditions were sampled and analyzed throughout the maturation period. Several quality characteristics were determined, including anthocyanin content. The objective of the experiments was to investigate which climatic determinants were most important for anthocyanin accumulation in the berries. Temperature and irradiance data, observed over time with a very thin discretization step, are called functional data in statistics. We developed the procedure SpiceFP (Sparse and Structured Procedure to Identify Combined Effects of Functional Predictors) to explain the variations of a scalar response variable (a grape berry quality variable for example) by two or three functional predictors (as temperature and irradiance) in a context of joint influence of these predictors. Particular attention was paid to the interpretability of the results. Analysis of the data using SpiceFP identified a negative impact of morning combinations of low irradiance (lower than about 100 μmol m−2 s−1 or 45 μmol m−2 s−1 depending on the advanced-delayed state of the berries) and high temperature (higher than 25oC). A slight difference associated with overnight temperature occurred between these effects identified in the morning.

Evolution of the amino acids content through grape ripening: Effect of foliar application of methyl jasmonate with or without urea

The parameters that determine the grape quality, and therefore the optimal harvest time, suffer variations during berry ripening, related to climate change, with the widely known problem of the gap between technological and phenolic maturities. However, there are few studies about its incidence on grape nitrogen composition. For this reason, the use of an elicitor, methyl jasmonate (MeJ), alone or with urea, is proposed as a tool to reduce climatic decoupling, allowing to establish the harvest time in order to achieve the optimum grape quality. The aim was to study the effect of MeJ and MeJ+Urea foliar applications on the evolution of Tempranillo amino acids content throughout the grape maturation. Three treatments were foliarly applied, at veraison and 7 days later: control (water), MeJ (10 mM) and MeJ+Urea (10 mM+6 kg N/ha). Grape samples were taken at five stages of maturation: day before the first and second applications, 15 days after the second application (pre-harvest), harvest day, and 15 days after harvest (post-harvest). The amino acids analysis of the samples was carried out by HPLC. Results showed that the evolution of amino acids was similar regardless of the treatment; however, foliar applications influenced the nitrogen compounds content, i.e., there was no qualitative effect but quantitative one. Most of the amino acids reached their maximum concentration in pre-harvest, being higher in grapes from the treatments than in the control. In general, no differences in grape amino acids content were observed between MeJ and MeJ+Urea treatments. Foliar applications with MeJ and MeJ+Urea enhanced the grape amino acids content, without affecting their profile, helping to optimize their quality and allowing to establish a more complete grape ripening standard. Therefore, MeJ and MeJ+Urea foliar applications can be a simple agronomic practice, which has shown promising results in order to enhance the grape quality.