IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Tracing glycosidically-bound smoke taint markers from grape to wine

Tracing glycosidically-bound smoke taint markers from grape to wine

Abstract

The increasing frequency of wildfires on the West Coast of the USA is seen as a significant risk for the grape and wine industry. Research has shown that perceived smoke impact in wines correlates with increases in volatile phenols (VPs) in grapes exposed to fresh smoke. During wildfires large quantities of volatile phenols are released into the air due to the thermal degradation of lignin. Besides the detectable free forms of these VPs, a large portion of VPs are stored in the grapes as various nonvolatile glycosides, which can be enzymatically/chemically released during fermentation and wine aging. Remarkably, the mechanism of VP glycosylation is not well understood, making it challenging to predict the smoke taint potential of a particular wine by simply analyzing free VPs or their corresponding acid-labile forms. In this study, clusters of Cabernet Sauvignon grapes were exposed to known amounts of isotopic volatile phenols in a contained atmospheric system. After the exposure, the glycosylation of absorbed isotopic volatile phenols in grapes was traced and identified by UHPLC-qTOF-MS. In addition, both the free and acid-labile forms of isotopic VPs in the exposed grape were analyzed by GC-MS. Exposed grapes were also micro-fermented and the isotopic VPs’ levels of juice/must were monitored every two days until fermentation was completed. Finally, the obtained wines were analyzed by GC-MS for the free and acid-labile volatile phenols, while the related glycosides were determined by UHPLC-qTOF-MS. Grape enzyme activity showed variable ability in forming mono-, di- and trisaccharide volatile phenols when exposed to volatile phenols in this in vitro study. By tracing the hydrolysis of isotopic VP-glycosides and the levels of related VPs during micro fermentations, this study expands the knowledge of the correlation between different forms of volatile phenols and the related glycosides. 

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Yan Wen1, Oberholster Anita1 and Arias-Pérez Ignacio1

1Department of Viticulture and Enology, University of California Davis, Department of Viticulture and Enology, University of California Davis, Davis, 95616, CA, USA

Contact the author

Keywords

smoke taint, volatile phenols, glycosides, fermentation, tandem mass spectrometry

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Metatranscriptomic analysis of “aszú” berries: the potential role of the most important species of the grape microbiota in the aroma of wines with noble rot

Botrytis cinerea has more than 1200 host plants and is one of the most important plant pathogens in viticulture. Under certain environmental conditions, it can lead to the development of a noble rot, which results in a specific metabolic profile, altering physical texture and chemical composition. The other microbes involved in this process and their functional genes are poorly characterised. We have generated metatranscriptomic [1,2] and DNA metabarcoding data from three months of the Furmint grape variety, representing the four phases of noble rot, from healthy berries to completely dried berries.

Vintage influence on Grenache N, Syrah N and Mourvedre N in Côtes du Rhône (France)

Vintage is part of « terroir ». The aim of this work is to study, through vine and berry parameters, the effect of vintage on the three major red grape varieties in Côtes du Rhône : Grenache N, Syrah N and Mourvedre N. We first characterized vintages 1997 to 2003, highlighting similar features in grape development across the different cultivars since 2001 only.

Somatic embryogenesis and polyploidy in grapevine: morphological shoot and leaf traits variations

Somatic embryogenesis (SE) has been used in a variety of biotechnology applications such as virus elimination, cryopreservation, induced mutagenesis and genetic transformation. The SE induction process may cause DNA alterations and ploidy changes, which may provide a source of genetic variability useful for the improvement of agronomic characteristics of plants. This research aims at investigating the spontaneous alterations of the genome in grapevine plants regenerated through SE. Regenerants obtained from different embryogenic events from three different grapevine genotypes (Catarratto, Frappato and Nero d’Avola) were analysed.

Optimised extraction and preliminary characterisation of mannoproteins from non-Saccharomyces wine yeasts

The use of non-Saccharomyces yeast species for the improvement of wine technological and oenological properties is a topic that has gained much interest in recent years [1]. Their application as co-starter cultures sequential to the inoculation of Saccharomyces cerevisiae and in aging on the lees has been shown to improve aspects such as protein stability and mouthfeel [2].

Plastic debris at vines: carriers of pollutants in the environment?

Modern agriculture employs large amounts of plastics, such as mulching and greenhouse films, thermal covers, plant protection tubes and tying tape. The latter two types are very common in viticulture. Guard tubes are employed to protect young vines from mechanic and atmospheric damage, whilst polymeric tying tape has replaced natural-origin materials to hold the canopy of vines. Both materials are made on synthetic polymers, which include a range of additives to improve their environmental stability remaining in the environment of vineyards for years. During this time, they are exposed to the range of pesticides (fungicides, insecticides and in a lesser extend herbicides) applied to vines.