Assessing geographical origin of Diqing wines based on their elemental and isotopic profiles

Characterization of grape and wine elemental constitution is essential in tracing their geographical origin. The traceability of wine provenance in China is conducive to implementing regional product quality protection. The aim of the present study was to investigate the multi-element profile of subregions and combine the variables of grapes and wine to assess the geographical origin. Grape and wine samples were collected from three towns in Deqin County, plateau of Diqing, China. The oxygen and carbon stable isotope ratios and the concentrations of 45 elements were measured. The interannual variability of element contents in grape and wine samples was less than 40 %. The correlation of elements between grape and wine samples can form fingerprint information of different regions. No significant variability in stable isotopes was observed among micro-vinifications from different wine-producing of the county. The grape data classification accuracy was 88.9 % by stepwise discriminant analysis (DA), and wine data classification accuracy was 95.2 % by an artificial neural network (ANN) model. The conclusion was that multielemental and isotopic information of grapes and wine will help to discriminate wine origin at the county level in China.