The evaluation of characteristic markers for organic and conventional wines differentiation by means of combination of some physico-chemical methods

摘要

Unambiguous identification of organic wines and their differentiation from conventional ones is important for state certification authorities as well as for consumers convince. In view of the complexity of the problem, objective markers are evaluated to find relevant characteristics of both types of wines. In this contribution, antioxidant activities and some other characteristics of Slovak organic and conventional wines from the same wine-making region and adjacent vineyards were investigated by UV-VIS-NIR and EPR spectroscopy in order to find characteristic markers suitable for their differentiation. Results obtained proved significant radical-scavenging and antioxidant properties of all samples, the higher for red wines, without respect on way of their production. In majority of cases, organic wines showed higher antioxidant activity than the conventional ones. Results obtained also indicated that the concentration of polyphenols in organic red wines was slightly higher compared to the conventional ones, the same for thiobarbituric acid reactive substances values as well as for ferric reducing power. However, the markers evaluated currently do not allow clear differentiation of organic and conventional wines. Processing of the experimental data by the methods of multivariate statistics brought only 88% correct differentiation of wines on the basis of the way of their production, which is still insufficient. Therefore, further experiments are in progress in which the number of mutually compared samples is to be expanded. The application of additional analytical and statistical methods is expected, as well.