Preventing Australian wine fraud Tuesday, 19 December 2017

The CSIRO is working on finding a unique chemical fingerprint that will identify Australian wines from those overseas to protect our $2.22 billion export market from fraud. With the potential to narrow that fingerprint down to a single vineyard, engineers involved in agriculture, chemicals, bulk materials handling, and the environment will find this of interest as will other engineers who enjoy the odd tipple.

Knowing exactly what makes an Australian wine unique “is going to be critical”, according to the CSIRO, in combatting the growing worldwide problem of wine fraud. Low cost wine or different wines can easily be blended and labelled for fraudulent sale, and open up the potential for contamination. Shoring up the reputation of Australian wine is particularly crucial as 50% of our famous fermented grape juice is shipped in bulk and bottled overseas.

In collaboration with the Australian Wine Research Institute, the CSIRO is working on identifying a unique isotope signature. To determine the origin of wine using chemical markers depends on analysing parameters related to geology, water, environment and climate, as well as understanding the impacts of winemaking techniques. Australia’s geology and climate are different to the rest of the world so these unique chemical fingerprints will be used to identify authenticity, the CSIRO says.

Wine can contain a range of elements such as sodium, potassium, calcium and magnesium and organic compounds of varying concentrations that make accurate chemical isotopic analysis challenging. The CSIRO conducted a study that analysed 231 Australian wines and compared them with 37 from bulk wine producing countries. Cabernet sauvignon, pinot noir, and chardonnay were analysed.

For isotopic analysis, the wine samples are evaporated to pre-concentrate elements and digested using strong acids to remove organic material. Using column purification chemistry, a particular element is purified from potentially interfering matrix ions using ion exchange resins and acid elution procedures. The purified samples are analysed using a high resolution multi-collector inductively coupled plasma-mass spectrometer (MC ICP-MS) to determine isotopic ratios with high precision and accuracy.

Strontium is a very effective trace element for this analysis, according to the CSIRO, as it distinguishes between different types of groundwater and has high concentrations in wines. Over the last decade, the element has been used in authenticating cheese, coffee, milk, and orange juice.

The CSIRO has revealed that strontium isotope ratios, combined with a different set of trace elements - boron, barium, cobalt, lithium, manganese, nickel, and rubidium – can help distinguish between major wine producing regions in Australia.

A capability for wineries to do their own quality control checks is now being developed. The tool for industry will be low cost and easy to use to ensure confidence and manage reputations. The CSIRO estimates it will be available in two to three years.

Image: CSIRO