Citrus Australia leads first Origin Verification Program for Australian Citrus Fruit

Through an Agriculture Victoria Food to Market program, Citrus Australia has conducted a study which is the first of its kind, to characterise Australian oranges at both a country and regional level, using laboratory testing of trace elements and isotope ratios.

The key goal of the project was to provide an internationally accepted laboratory traceability method that addressed two key questions:

• Using trace elements or isotopes, can we determine if the origin of an orange is from Australia as opposed to another country?

• Using the same techniques, can we differentiate place of origin of Australian oranges into one of the 5 Australian growing regions?

The project successfully answered ‘yes’ to both questions.

The increased global demand for high-quality food products has led to premium prices for Australian products in international markets.

However, with market growth also comes the need for increased traceability and origin verification of products to avoid food fraud, protect brands and ensure continued consumer satisfaction.

Isotopes and trace elements in agricultural products such as fruit are derived from the soil, and differ depending on local geology, climatic and environmental conditions, and agricultural practices.

Isotope ratios and trace elements provide a form of laboratory identification at the atomic level, specific to a particular product and region that cannot be tampered with or altered.

The National Isotope and Trace Element (NITE) project collaborated with GNS Science, New Zealand, to analyse trace elements and isotopes of Australian Navel oranges to see if their origin could be verified.

“Once you remove all the labels from an orange, you can still find out where it’s from and it’s because of these intrinsic atoms that are infused into the orange you can’t tamper with, you can’t add to them or take them away.

“They’re locked in there so the orange never lies,” said Karyne Rogers, Senior Environmental Scientist of GNS Science.

The project was conducted with Australian and competitor country fruit from the harvest seasons of 2021 and 2022.

When using a combination of trace elements and isotopes in this study, Australian oranges were able to be discriminated from other countries at a rate of 97.3 per cent.

Oranges from Australian regions could be discriminated from each other at a rate of 92.3 per cent.

These high results demonstrate the opportunities for characterising Australian fruit through laboratory testing during times of crisis.

“We found that there were key trace elements and isotopes that clearly characterised Australian oranges.

“This is helpful to know, that in a crisis when other traceability mechanisms need extra evidence, are not available or have been tampered with, we can show proof to verify the origin of the fruit,” said Nathan Hancock, CEO of Citrus Australia.

“In the future Citrus Australia hopes to build the NITE dataset by adding more data from around the country and more variation on the varieties too.

“We may identify growers that are interested in characterisation of their own fruit as well as entering into collaborative studies with global partners or peak bodies to add to the dataset and strengthen citrus traceability around the world,” said Mr Hancock.

Limitations of isotope and trace element testing include the expense, time and analytic expertise involved in creating the data points.

Encouragingly, oxygen isotope ratios in orange juice have shown particular characterisation for Australian oranges in this study, and this single test has the potential to be developed as a rapid screen to confirm whether or not fruit is from Australia, with results potentially available within a few days of a crisis occurring.

Other forms of rapid traceability are also critical for the protection of Australian citrus.

Further collaborative projects with Agriculture Victoria have also developed digital traceability through fruit labelling and created the National Citrus Map.

For further information, contact comms@citrusaustralia.com.au

View the The National Isotope and Trace Element (NITE) Profile for Australian Citrus here.