Grapes from the geographical areas of the Black Sea: Agroclimatic growing conditions and evaluation of stable isotopes compositions in scientific study

The report considers the agroclimatic conditions in the Black Sea districts of cultivation and processing of grapes - the Black Sea Lowland, the Crimean Peninsula and the South-west coastal areas of the Greater Caucasus. The IRMS/SIRA techniques - Flash combustion (FC-IRMS/SIRA) & Isotopic equilibration (EQ-IRMS/SIRA) - were first applied for the evaluation of carbon and oxygen isotopes ratios in the components of grapes from the Crimean Peninsula. The C-13/C-12 ratios were studied by the FCIRMS/SIRA in carbohydrates and organic acids in authentic samples of 8 grape varieties from the 2015 harvest. The EQ-IRMS/SIRA was applied to measure the O-18/O-16 ratios in intracellular water of grapes. The measured delta C-13(VPDB) value ranges from -25.01 to -21.01%(0) (for carbohydrates), and from -25.09 to -21.30%(0) (for organic acids). To evaluate the extent of biological isotope fractionation the O-18/O-16 ratios were measured in ground water and water of atmospheric precipitates from the Crimean Peninsula. Compared to ground (delta O-18(VSMOW) from -10.85 to -8.14%(0)) and atmospheric (average delta O-18(VSMOW) -2.85%(0)) waters, the intracellular water of Crimean grape varieties is found to be enriched with O-18 isotope. The delta O-18(VSMOW) value of the grape intracellular water varies from 2.34 to 5.29%(0) according to agroclimatic conditions of the season