Origin verification and detection of counterfeit Australian wines
Wine is periodically the subject of substitution or counterfeiting. While some cases can be easily detected, such as those involving spelling errors on labels, other cases suggest that an increasingly sophisticated approach to addressing counterfeiting is required. Efforts to establish the authenticity of a wine sample have been underway for many years, particularly in Europe, with mixed success. This project had the aim of protecting Brand Australia, and ultimately individual producer brands, by investigating the possibility of a robust authenticity framework based on the discriminating power and robustness of several classes of determinants that draw on differences arising from unrelated variables such as climate, soil/petrology or genetic source.
For a recently completed proof of concept study 231 Australian wine samples and 37 international samples were obtained from reputable sources. The strontium isotope ratio and a set of trace element concentrations were determined in this set of wines and the data were compared between the Australian wines and the international wines. In addition, the potential of spectral analysis for the differentiation of wines from Australian versus other countries was assessed and published methods for the isolation of wine DNA were evaluated.
Sr isotope ratios were demonstrated to be a useful parameter in the differentiation of geographically defined sample sets, both within Australia or between Australia and other countries. A combination of this ratio with selected compositional data allowed Australian wines to be differentiated from wines from other countries. Within Australia, the data suggest it may be possible to differentiate production zones using Sr isotope ratios and a combination of trace elements.
While the initial study has demonstrated the feasibility of the approach, as with any technique that requires confidence limits to be set around concentrations of discriminant parameters, the next stage of this project will require analysis of more samples to ensure that the final dataset is robust. This is particularly the case with the non-Australian wines which by definition cover a much wider geographical area and also for the 67 defined GIs in Australia, where more samples are needed to cover the full range of crustal element variation.