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.

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

Keywords

Tokaj, polyphenol, aszú, wines, tyrosol, Botrytis

Tags

IVES Conference Series | Terroir 2014

Citation

Related articles…

Influence of agronomic practices in soil water content in mid-mountain vineyards

In the context of LIFE project MIDMACC (LIFE18 CCA/ES/001099), several pilots have been installed in vineyards in mid mountain areas of Catalonia (NE Spain) to test well stablished agronomic practices to increase the adaptation of Mediterranean mid mountain to climate change. Soil water content (SWC) at three different depths (15, 30 and 45cm) was measured in continuum from August 2020. One pilot (WC) included a well-established green cover (GC), a new GC (NC) and a conventional soil management (CM, tilling+herbicides). NC presented an intermediate state between WC and CM, responding similarly to CM in autumn but quickly reaching similar SWC to WC, then following the same evolution till next spring, with CM presenting lower values along autumn and winter. Then vegetation activation decreased SWC in all plots, (much slower in CM, lacking GC). Sensibility to spring rains is again intermediate for NC, which joins SWC evolution of CM by the end of spring till next autumn. It is expected that NC will resemble WC more and more as its GC develops. In the pilot combining vine training (VSP vs Gobelet) and hillside management (slope vs terrace), no clear pattern could be related with these conditions. However, both terraces seem to be more sensitive to spring rains. A third pilot included new vineyards (7 and 1 year old). In the new vineyard (N), higher canopy development, a spontaneous green cover and row straw resulted in a slower SWC dynamic, not so sensitive to rains but conserving more soil water in spring and most of summer, even with presumably a higher water extraction by vines. In the newest vineyard (VN) the deepest sensor is still sensitive to rain events all over the year and SWC is always highest at this depth, revealing small water capture by vines.

Analysis of vineyard soil after mulching with municipal solid waste (MSW)-compost

The use of compost as amendment in agriculture is a well-established practice, strongly recommended for numerous benefits.

Assessment of environmental sustainability of wine growing activity in France

To meet the demand of assessment tool of vine growers and their advisers we adapted to the vine production the INDIGO® method to developed initially for arable farming.

Effects of long-term drought stress on soil microbial communities from a Syrah cultivar vineyard

Changes in the rainfall and temperature patterns affect the increase of drought periods becoming one of the major constraints to assure agricultural and crop resilience in the Mediterranean regions. Beside the adaptation of agricultural practices, also the microbial compartment associated to plants should be considered in the crop management. It is known that the microbial community change according to several factors such as soil composition, agricultural management system, plant variety and rootstock.

Grapevine gas exchange responses to combined variations of leaf water, nitrogen and carbon status – a case of study of fungi tolerant varieties

In the context of climate change and the need to reduce inputs, optimising photosynthesis and grapevine performance requires a better understanding of the interactions between water status, nitrogen availability, and source-sink relationships.