Macrowine 2021
IVES 9 IVES Conference Series 9 What do we know about the kerosene/petrol aroma in riesling wines?

What do we know about the kerosene/petrol aroma in riesling wines?

Abstract

AIM: 1,1,6-Trimethyl-1,2-dihydronaphthalene (TDN) is a controversial aroma component found in Riesling wines. It belongs to the family of C13-norisoprenoids and is mainly associated with kerosene/petrol notes. TDN can add complexity to the wine aroma at medium – low concentrations and deteriorate the wine bouquet when its content is high. No TDN aromas are usually perceived in young Riesling wines, but they can appear after several years of aging due to the gradual formation of TDN. Management of TDN in Riesling wines is an actual task, since global warming can promote formation of this compound and compromise the aromatic composition of wine. Therefore, the aim of the current work was, firstly, to study the sensory particularities of TDN in Riesling wine at various concentrations. Secondly, to investigate the ability of bottle closures to absorb (scalp) TDN from Riesling wine under various storage conditions. These studies also include the comparative assessment of our findings with previously published data.

METHODS: sensory analysis, GC-MS (SBSE), HPLC,1H-NMR and other methods related to the synthesis and determination of TDN.

RESULTS: First of all, the method of the synthesis of highly purified TDN (95% and 99.5%) was optimized [1]. The obtained TDN was used for the calibrations in GC-MS analysis and for the sensory and TDN scalping studies. As a result, three sensory thresholds for TDN in Riesling wine were determined: detection threshold (about 4 μg/L), recognition threshold (about 10-12 μg/L) and rejection threshold (about 71-82 μg/L) [2]. It was also demonstrated, that the TDN aroma recognition was easier in the cooled wine. The defined thresholds were discussed in relation to the previously reported sensory thresholds determined by other panels and in other wine matrices. In the experiment of TDN scalping, five bottle closures were studied under storage conditions which varied by ambient temperature (14 °C vs 27 °C) and bottle position (horizontal vs vertical) [3]. A large difference in TDN scalping rate was observed for synthetic and glass stoppers depending on the storage conditions. For example, the TDN absorbance from the wine was more than three times faster by synthetic stoppers at the lower storage temperature compared to the higher one (vertical bottle position). Cork stoppers demonstrated a fast scalping process in all storage scenarios, absorbing up to 40% TDN. In the wine bottled with BVS screw caps, only a minor decrease of TDN was found in all storage variants.

CONCLUSIONS:

TDN is an aroma compound that requires effective control tools in Riesling wines. The described results of the sensory analysis can be used as a reference for the desired content of TDN in finished Riesling wines. At the same time, the outcomes of the TDN scalping study provide a deeper understanding of the impact of bottle closures and storage conditions on the TDN content in wine.

DOI:

Publication date: September 22, 2021

Issue: Macrowine 2021

Type: Article

Authors

Andrii Tarasov, Nicoló Giuliani (1), Alexey Dobrydnev (2), Christoph Schuessler (1), Nikolaus Müller, Yulian Volovenko (2), Doris Rauhut (1), Rainer Jung (1) 

(1) Hochschule Geisenheim University (Germany) (2) Faculty of Chemistry, Taras Shevchenko National University of Kyiv (Ukraine)

Contact the author

Keywords

1,1,6-trimethyl-1,2-dihydronaphthalene (tdn); sensory threshold; scalping; bottle closure; wine

Citation

Related articles…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.