IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Study of the grape glycosidic aroma precursors by crossing SPE-GC/MS, SPME-GC/MS and LC/QTOF methods

Study of the grape glycosidic aroma precursors by crossing SPE-GC/MS, SPME-GC/MS and LC/QTOF methods

Abstract

Depending on the variety, grapes contain several chemical classes of aromatic compounds (i.e., terpenols, norisoprenoids, benzenoids) mainly stored as glycosides in berry skin. These secondary metabolites are the aromatic precursors fraction of grape which is liberated in wine during fermentation. Knowledge of their profile is often required to estimate the aromatic potential transferable to the wine and for chemotaxonomic aims (Nasi et al., 2008; Ferreira and Lopez, 2019).

In general, the methods used to study glycosidic aroma profile involve sample extraction and concentration by passage of large volumes of must or grape extract through a SPE cartridge (the stationary phases commonly used are 1-10 g of C18 or polystyrene-divinylbenzene), then the methanolic fraction eluted containing the glycoside compounds is carried to dryness, resolubilized using a citrate pH 5 buffer, and an enzymatic hydrolysis is carried out overnight to liberate the aglycones which are then analyzed by GC/MS. Main advantage of SPE is until 1000-fold concentration of sample which allows to detect also compounds present at low level but which can play important role in determining the organoleptic characteristics of wine. Usually, the selectivity of SPE towards the compounds studied is low, so performing quantitation by expressing the compounds as mg internal standard/kg grape provides accuracy acceptable for the aim of the study. On the other hand, SPE is laborious, needs long time and is hardly applicable in quality control laboratories. SPME is faster but the selectivity of fiber towards the analytes is often very different and to perform acceptable quantitative analysis it is essential the calculation of calibration curves. Unfortunately, just few standards of the grape aroma compounds are commercially available (Panighel et al., 2014).

In this study SPE-GC/MS and SPME-GC/MS methods are compared by performing analysis of a set of model standard solutions and grape must samples. The use of several internal standards allows to estimate recoveries of the analytes and calculation of corrective coefficients between the two methods. To have also information free of enzymatic artifacts, GC/MS results are crossed with profile of glycosidic aroma precursors determined by LC/QTOF analysis (Flamini et al., 2014).

The study is finalized to develop a quick SPME-GC/MS method which provides exhaustive and reliable qualitative and semi-quantitative information on the grape glycosidic aroma precursors

References

Nasi A., Ferranti P., Amato S., Chianese L. (2008). Food Chem. 110: 762-768
Ferreira V., Lopez R. (2019). Biomolecules 9(12): 818- doi:10.3390/biom9120818
Panighel A., Flamini R. (2014). Molecules 19: 21291-21309 doi:10.3390/molecules191221291
Flamini R., De Rosso M., Panighel A., Dalla Vedova A., De Marchi F., Bavaresco L. (2014). J. Mass Spec. 49(12): 1214-1222 doi:10.1002/jms.34411214

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Panighel Annarita¹, Fugaro Michele², Mazzei Raffaele Antonio², De Rosso Mirko¹, De Marchi Fabiola¹ and Flamini Riccardo¹

¹Council for Agricultural Research and Economics – Viticulture & Oenology (CREA-VE)
²Dipartimento dell’Ispettorato centrale della tutela della qualità e repressione frodi dei prodotti agroalimentari – ICQRF NORD-EST

Contact the author

Keywords

Glycosides, grape, aroma, mass spectrometry

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

Sustainable fertilisation of the vineyard in Galicia (Spain)

Excessive fertilization of the vineyard leads to low quality grapes, increased costs and a negative impact on the environment. In order to establish an integrated management system aimed at a sustainable fertilization of the vineyards, nutritional reference levels were established. For this purpose, 30 representative vineyards of the Albariño variety were studied, in which soil and petiole analyses were carried out for two years and grape yield and quality at harvest were measured. In both years of study, soil pH, calcium, sodium and cation exchange capacity were positively correlated with calcium content and negatively correlated with manganese in grapes. Irrigated vineyards had higher levels of aluminium in soil and lower levels of calcium in petiole. Climatic conditions were very different in the years of the study. The year 2019 was colder than usual, in 2020 there was a marked water stress with high summer temperatures. This resulted in medium-high acidity in grapes in 2019 and low acidity in 2020, with sugar levels being similar both years. A very marked decrease in must amino nitrogen was observed in 2020, with ammonia nitrogen remaining stable. The correlation of acidity and sugar values in grapes with soil and petiole analysis data made it possible to establish reference levels for the nutritional diagnosis of the Albariño variety in this region. Based on these results, an easy-to-use TIC application is currently being created for grapegrowers, aimed at improving the sustainability of the vineyard through reasoned fertilization. This study has now been extended to other Galician vine varieties.

Impact of geographical location on the phenolic profile of minority varieties grown in Spain. II: red grapevines

Because terroir and cultivar are drivers of wine quality, is essential to investigate theirs effects on polyphenolic profile before promoting the implantation of a red minority variety in a specific area. This work, included in MINORVIN project, focuses in the polyphenolic profile of 7 red grapevines minority varieties of Vitis vinifera L. (Morate, Sanguina, Santafe, Terriza Tinta Jeromo Tortozona Tinta) and Tempranillo) from six typical viticulture Spanish areas: Aragón (A1), Cataluña (A2), Castilla la Mancha (A3), Castilla –León (A4), Madrid (A5) and Navarra (A6) of 2020 season. Polyphenolic substances were extracted from grapes. 35 compounds were identified and quantified (mg subtance/kg fresh berry) by HPLC and grouped in anthocyanins (ANT) flavanols (FLAVA), flavonols (FLAVO), hydroxycinnamic (AH), benzoic (BA) acids and stilbenes (ST). Antioxidant activity (AA, mmol TE /g fresh berry) was determined by DPPH method. The results were submitted to a two-way ANOVA to investigate the influence of variety, area and their interaction for each polyphenolic family and cluster analysis was used to construct hierarchical dendrograms, searching the natural groupings among the samples. Sanguina (A3) had the most of total polyphenols while Tempranillo (A5) those of ANT. Sanguina (A2) and (A3) reached the highest values of FLAVO, FLAVA and AA. These two last samples had also the maximum of AA. The effect cultivar and area were significant for all polyphenolic families analyzed. A high variability due to variety (>50%) was observed in FLAVA and the maximum value of variability due to growing area was detected in AA (86.41%), ANT and FLAVO (51%); the interaction variety*zone was significant only for ANT, FLAVO, EST and AA. Finally, dendrograms presented five cluster: i) Sanguina (A2); ii) Sanguina (A3); iii) Tempranillo (A5); iv) Tempranillo (A3); Terriza (A3,A5), Morate (A5,A6); v) Santafé (A1,A6); Tortozona tinta (A1,A3,A6); Tinta Jeromo (A3,A4).

Climate projections over France wine-growing region and its potential impact on phenology

Climate change represents a major challenge for the French wine industry. Climatic conditions in French vineyards have already changed and will continue to evolve. One of the notable effects on grapevine is the advancing growing season. The aim of this study is to characterise the evolution of agroclimatic indicators (Huglin index, number of hot days, mean temperature, cumulative rainfall and number of rainy days during the growing season) at French wine-growing regions scale between 1980 and 2019 using gridded data (8 km resolution, SAFRAN) and for the middle of the 21th century (2046-2065) with 21 GCMs statistically debiased and downscaled at 8 km. A set of three phenological models were used to simulate the budburst (BRIN, Smoothed-Utah), flowering, veraison and theoretical maturity (GFV and GSR) stages for two grape varieties (Chardonnay and Cabernet-Sauvignon) over the whole period studied. All the French wine-growing regions show an increase in both temperatures during the growing season and Huglin index. This increase is accompanied by an advance in the simulated flowering (+3 to +9 days), veraison (+6 to +13 days) and theoretical maturity (+6 to +16 days) stages, which are more noticeable in the north-eastern part of France. The climate projections unanimously show, for all the GCMs considered, a clear increase in the Huglin index (+662 to 771 °C.days compared to the 1980-1999 period) and in the number of hot days (+5.6 to 22.6 days) in all the wine regions studied. Regarding rainfall, the expected evolution remains very uncertain due to the heterogeneity of the climates simulated by the 21 models. Only 4 regions out of 21 have a significant decrease in the number of rainy days during the growing season. The two budburst models show a strong divergence in the evolution of this stage with an average difference of 18 days between the two models on all grapevine regions. The theoretical maturity is the most impacted stage with a potential advance between 40 and 23 days according to wine-growing regions.

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.