Macrowine 2021
IVES 9 IVES Conference Series 9 NMR profiling of grape musts from some italian regions

NMR profiling of grape musts from some italian regions

Abstract

With wine fraud, being a widespread problem [1], the need for more sophisticated and precise analytical methods of its detection remains ever persistent. Nuclear magnetic resonance (NMR) spectroscopy has been widely used for analysis of wine in recent years [2,3], but wine musts were much less studied; in fact, only one paper dealt with the NMR spectra of actual musts [4]. Difficulties arise mostly because grape musts are “live” objects, which undergo rapid fermentation at room temperature, if not inhibited either by freezing or chemical preservative; but even such measures are not sufficient to halt it completely [5]. We have investigated over 300 samples of grape must from 17 of 20 different Italian regions using 1H NMR spectroscopy with water signal suppression, postprocessing in the MatLab software with dynamic alignment [6] and optimized binning [7] to alleviate the effect of fermentation on the chemical shifts of mobile protons. After that, multivariate statistics was performed with techniques such as PCA, PLS-DA and OPLS-DA with respect to various group parameters such as regions, vitivinicultural zones, harvest periods and grape varieties. Advantages and drawbacks of each method were addressed.

DOI:

Publication date: September 13, 2021

Issue: Macrowine 2021

Type: Article

Authors

Pavel Solovyev

Fondazione Edmund Mach (FEM), via E. Mach 1, 38010, San Michele all’Adige, Italy ,Matteo Perini, Fondazione Edmund Mach (FEM), via E. Mach 1, 38010, San Michele all’Adige, Italy Pietro Franceschi, Fondazione Edmund Mach (FEM), via E. Mach 1, 38010, San Michele all’Adige, Italy Luana Bontempo, Fondazione Edmund Mach (FEM), via E. Mach 1, 38010, San Michele all’Adige, Italy Federica Camin, Fondazione Edmund Mach (FEM), via E. Mach 1, 38010, San Michele all’Adige, Italy, University of Trento, via Mach 1, 38010 San Michele all’Adige (TN), Italy

Contact the author

Keywords

grape musts, nmr spectroscopy, profiling, multivariate statistics

Citation

Related articles…

Characterization of a unique mannan from Starmerella bacillaris for protein stabilization in white wine

Yeast cell wall components are valuable biotechnological tools with applications in oenology and beyond [1], [2].

Feasibility of pre-fermentative oenological tannins addition to enhance volatile composition and aroma perception in white wines

Oenological tannins (OETs) are an alternative to sulphur dioxide due to their antioxidant and antioxidase properties in the early phase of winemaking [1,2].

From a local to an international scale: sensory benchmarking of PDO wines. Quincy and Reuilly PDO wines (Sauvignon blanc) as a case study (France)

In a collective marketing strategy, the Protected Designation of Origin (PDO) can be used as a quality indicator. To highlight terroir specificities, it is useful to know how the wines are positioned on the local, national or international market from a sensory point of view. This is especially true for a comparison of varietal wines (e.g. Sauvignon blanc). We focus on the case of two closed Loire Valley PDO (France): Quincy and Reuilly. Three distinct tastings were organized. Firstly, at the local level comparing the 2 PDO (11 and 9 wines, 17 professional assessors); secondly at a regional level adding 3 closed PDO: Menetou-Salon, Sancerre and Pouilly-Fumé (3 wines per PDO, 16 assessors) and thirdly at an international level comparing these 5 PDO with Sauvignon Blanc wines coming from South Africa, New Zealand and Chile (1 to 3 wines per PDO, 19 assessors). All the wines were from the 2019 vintage and were considered to have a traditional elaboration process without contact with oak. A sensory descriptive analysis was performed using an aroma wheel allowing to combine a Check-All-That-Apply methodology, often used in sensory benchmarking, with a hierarchical structuration of the attributes. The aim is to facilitate data acquisition in a professional context without common training, to consider the hierarchical relationships among the attributes during the data analysis and to be able to characterize wines with a large range of sensorial variability. We use univariate, multivariate and clustering analyses. Similarities and differences between Quincy and Reuilly PDO wines and other Sauvignon blanc wines were identified. Specific attributes can distinguish the two PDO and different proximities exist with other local PDO, while clear differences were observed compared to international wines. Our study contributes to propose and discuss a method to do a wine sensory benchmarking highlighting sensory specificities linked to origin.

The role of soil water holding capacity and plant water relations in zone/terroir expression

The spatial variability in soil type and depth and water holding capacity is very high in many viticultural regions of the world. Differences in rooting depths and water extraction profiles and their seasonal dynamics add additional variability and it is extremely difficult to deduct direct causal relationships between these factors and fruit

Portable NIR spectroscopy for nutrient profiling in rootstock and scion material: enhancing decision-making in the grafting industry

The success of grafting in viticulture is deeply influenced by the nutrient composition of both rootstock and scion
materials. Key components such as nitrogen and carbohydrates play a crucial role in graft compatibility, establishment,
and overall plant vigor [1].