Methodology refinement for the identification of adulterated wine produce

Abstract

Detection of adulterated produce is a pressing matter of the day not only for domestic winemaking, but for the world community of wine producers as a whole. According to the International Center for Alcohol Policies, 30% of the alcohol on the world market is counterfeit, while 20% of all the wine consumed is adulterated. Methods and forms of wine adulteration are constantly being upgraded, which necessitates the development of new methods and approaches to improve the efficiency and effectiveness of counterfeit identification and detection. Wine adulteration is facilitated by availability of a wide range of food additives prohibited in domestic winemaking. The work aims to establish a system of indicators to differentiate between genuine and adulterated wines. The objects of research are genuine and adulterated wines; model systems obtained by introducing authorized (concentrated grape must) and prohibited (DL-tartaric acid, sweeteners, glycerin, flavours, dyes) additives. Glycerol content, sugar and organic acids profile were determined by high-performance liquid chromatography method, aroma-building substances - by gas-liquid chromatography method; monomeric anthocyanins - pH differential method; optical characteristics, composition and forms of phenolic substances – by spectrophotometric methods. A total of 1200 samples were examined. Additives prohibited in winemaking were systematized by groups and their determination methods, which made it possible to identify classification indicators constituting criteria for identifying fake wine colour, aroma and taste. In the study of genuine wines and counterfeits, the influence of various additives on the physico-chemical system of wine was determined, which made it possible to establish the pattern of trends in the values ​​of classified indicators. Change patterns were established for variations of these indicators in wine adulteration, where they are based on revealed value deviation tendencies, as compared to the range characteristic of genuine wines under the influence of illegitimate production methods.

The revealed patterns were used in the development of algorithms based on a dichotomous key to identify forbidden additives in wines, which made it possible to classify the samples under investigation into genuine and adulterated. The developed system of classification indicators and algorithms secures the identification of additives prohibited in winemaking: dyes and flavours of various origins; organic acids; glycerol; sugar-containing substances of non-grape origin; sugar-containing components in table and liqueur wines with discontinued fermentation.