Terroir 2014 banner
IVES 9 IVES Conference Series 9 Polyphenol content examination of Tokaji Aszú wines

Polyphenol content examination of Tokaji Aszú wines

Abstract

 There are two important conditions which determine the nascency of particular Tokaj wines comulatively: 

  • distinctive savour and fragance called the „aszú” taste and caused by Botritis c.
  • Tokaj nature which come from the barrel and other special aging methods 

We must state that two conditions above are only prevalent in the case when the processed grapes are full or over ripened, besides following the Tokaj wines preparation criterions (grape variety, soil, microclimate, vintage, etc.). These two conditions mentioned before were followed up only sensory based analysis up to now, altough the study of chemical idetified compounds which confirms these are obviuos. This study about the investigatation of the polyphenol compounds biological effect, next to definiate the tirosol, one of the simple phenol content from these wines. The grape stem and wine contents are changing during the infection of Botritis c., also the aminoacid content is decreasing. It is therefore assumed that the Tyrosine content derived from amino acids present in lower concentrations in the Tokaji wines. The Tyrosol (p-hydroxyphenyl ethanol) belongs to the simple phenols compounds and generated oxidative decarboxylation of the alcoholic fermentation only. It is oenological significance in sensory value itself, because it have a bitter taste, which could give that bitter flavour over 25 mg/l concentration. 

Also could be detect a significant differences in the simple phenolic and polyphenolic composition from each vintages at same sugar content level. We continue our investigations worthwhile. It is important to determine the polyphenolic compounds due to their positive health effects and simple polyphenols, including the amount of Tyrosol too, which also keep track of the Tokaj wines.

Download the PDF

DOI:

Publication date: August 18, 2020

Issue: Terroir 2014

Type: Article

Authors

S.D. Nyitrainé, B. Nagy, M. Kállay 

Corvinus University of Budapest, Institute of Viticulture and Oenology Department of Oenology H-1118 Budapest, Ménesi út 45. 

Contact the author

">Sárdy  

Keywords

Tokaj, polyphenol, aszú, wines, tyrosol, Botrytis

Tags

IVES Conference Series | Terroir 2014

Citation

Related articles…

Aromatic profile evolution of corvina, corvinone and rondinella grapes during withering

AIM AND METHODS: Grape withering is one of the key steps in the production of the most renowned red wines of the Valpolicella area, namely Amarone and Recioto. This practice, which was already used since Roman times, entails important modifications in grape composition and in the chemical and sensorial characteristics of the corresponding wines, especially in terms of aromatic profile. The aim of this research is evaluating the aromatic evolution during grape withering of the three main varieties used in Valpolicella wines: Corvina, Corvinone and Rondinella.Samples of the three varieties were analyzed at harvest and at different stages of withering, namely10%, 20% and 30% of weight loss. Free and glycosidically bound compounds were extracted and analyzed using Gas Chromatography- Mass Spectrometry (GC-MS). RESULTS: For all the samples the data were normalized to eliminate the effect of concentration due to grape dehydration. Terpene content and evolution varied considerably in relationship to grape variety. Corvinone was richer in cyclic terpenes (including phellandrene, limonene, and cymene) and they decreased during withering.
Read More

Juice carbon isotope discrimination is related to vine growth and fruit quality of Barossa Shiraz

Aim: Interactions between soil, climate and management that modulate vine growth, yield and grape composition are strongly defined by vine water availability and nutrient uptake during the season. Carbon isotope discrimination (δ13C) has been used as an integrative measurement of vine water availability during the season, with the potential to identify spatial variations of terroir in

Read More

Vertical cordon training system enhances yield and delays ripening in cv. Maturana Blanca

The growing interest in minority grape varieties is due to their potential for adaptation to global warming and their oenological capabilities. However, the cultivation of these varieties has often been limited due to their low economic efficiency. One such example is Maturana Blanca, a recently recovered and authorized minority grape variety in the DOCa Rioja region, known for its remarkable oenological potential but low productivity. This study aimed to increase the yield of Maturana Blanca by implementing the vertical cordon training system, which allowed for a higher number of buds per plant and an increased cluster count per vine.

Read More

Regional discrimination of shiraz using targeted and non-targeted analytical approaches

Aims: Shiraz is the most widely cultivated grape variety in Australia, and is grown under a range of viticultural and climatic conditions. Given its importance to the Australian wine sector, a number of studies have been conducted in recent years which involved a comprehensive assessment of grape composition, in order to objectively predict wine quality and style outcomes.

Read More

Effect of different foliar nitrogen applications on the must amino acids and glutathione composition in Cabernet Sauvignon vineyard

Cabernet Sauvignon is one of the most important winegrape varieties in Chile. However, temperature raise and decreased rainfall due to climate change can lead to grape quality decrease in certain areas. Amino acids are essential as nitrogen source for yeast but also directly affect grape quality serving as precursors of certain volatile compounds that enhance the wine bouquet. Besides, glutathione is an important tripeptide acting as antioxidant, preventing the appearance of browning pigments in must and exerts a protective effect in volatile compounds.

Read More