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.
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.
Keywords: Tokaj, polyphenol, aszú, wines, tyrosol, Botrytis