Search

Phenological stages of many grapevine cultivars appear in earlier parts of the year. However, we do not know how different cultivars are affected by this trend. The aim of this study was to compare the phenological stages of grapevine cultivars recorded in two different periods (1986–1998 and 2013–2018) in North Serbia (Vojvodina). The investigation was carried out on five red (Cabernet sauvignon, Merlot, Pinot noir, Prokupac, Probus) and five white cultivars (Chardonnay, Muscat ottonel, Riesling italico, Smederevka and Petra). The phenological observations included the beginning of budburst, flowering and veraison. The beginning of all phenological stages in all cultivars in the period (2013–2018) occurred in earlier parts of the year, compared to the historical data. Local cultivars (Prokupac, Probus, Smederevka and Petra) showed less shift of the beginning of budburst in respect to the historical data (only six days earlier) compared to the international cultivars. One of the most important phenological stages, flowering, has been shifted ten days in the earlier part of the year. The biggest differences were observed for the beginning of veraison. Now, it occurs earlier from 9 (Petra) to 17 days (Merlot). Duration of the period from budburst to flowering was inconsistent and cultivars required almost the same number of days as it was in the past. However, the duration between flowering and veraison was shorter in the last six years. The biggest difference was observed in Merlot where the period between flowering and veraison has been seven days shortened.

In early 1990's European Union has established new isotopic approach for detection of wine authenticity. In this article we setup the possibility of using new approach using new EIM – Module – IRMS (Ethanol Isotope Measurement – Module – Isotope Ratio Mass Spectrometry) instrumental technique and new analytical parameter δDn(δ2Hn) wine ethanol value, which represents δ2H value of non-exchangeable hydrogen stable isotope ratio in ethanol, with other isotopic species (δ18O values in wine water) to improve detection of illegal wine production practices such as addition of sugar and/or dilution with water. Total of 42 wine samples were analyzed. 10 wine samples (out of 42) were prepared from grapes by alcoholic fermentation and analyzed for δDn values of ethanol. 19 wine samples (out of 42) were collected from wine producers in Serbia plus 1 wine samples designated from United States was taken from Serbian market and analyzed for δDn values of ethanol, δ18O values in wine water and also δ13C values in wine ethanol. Furthermore 9 wine samples (out of 42) were taken from Hungarian market and analyzed for δDn values of ethanol, and also 3 wine samples (out of 42) were taken from Austrian market and analyzed for δDn values of ethanol. All experiments were done in 4 isotope laboratories located in US, Austria, Hungary and People's Republic of China. δDn values of ethanol were measured by using EIM Module connected to FlashHT 2000 pyrolizer (one laboratory – Imprint Analytics GmbH, Austria), while in other 3 laboratories (US – COIL – Cornell University, Stable Isotope Laboratory, Hungary – Isotoptech Ltd, Debrecen, Hungary and China – C.N.R.I.F.F.I. – China National Institute of Food and Fermentation Industries Limited) EIM Module was connected to TC/EA (High Temperature Conversion Elemental Analyzer). Peripherals in all laboratories were further interfaced with isotope ratio mass spectrometer. Furthermore δ18O values in wine water were measured by using Gas Bench II interfaced also with isotope ratio mass spectrometer (one laboratory – US). Obtained results from all 4 laboratories have shown that this new approach which uses δDn in wine ethanol is more effective in improving detection of illegal wine production practices (sugar enrichment and water dilution) and origin of ethanol, and also detecting the addition of corn or beet sugar, sugar syrup to wine, or dilution of grape must with water prior to alcoholic fermentation. Keywords: Wine authenticity; EIM – Module – IRMS; Stable Isotope; Isotope Ratio Mass Spectrometry; Wine; Watering; Chaptalization.