Extract from Organic Advantage Ed. 126 (BFA e-newsletter) October 2009 

Finding a way to pinpoint whether an organic product is in fact organic can be a challenge. A concrete and credible testing method for organic could go a long way in raising consumers' trust and value in organic products; by identifying businesses making fraudulent organic claims, and product mixing.

To address this issue, an international workshop on Organic Food Authentication - Challenge or Utopia? is being held on November 30th in Belgium by the European Commission Joint Research Centre.

Organisers say organic produce remains amongst the most difficult to monitor and control, with new challenges arising for international organic food certification and guarantee systems as the organic sector continues to develop rapidly.

''Currently all scientists can do is test for what should not be there (e.g. chemical pesticide residues)'' they state.

The event is expected to look at ideas and methods like those currently being developed by Dr. Karyne Rogers of GNS Science's National Isotope Centre in New Zealand.

Dr. Rogers is working with a technique known as stable isotope analysis which analyses the elemental carbon and nitrogen found in vegetables in order to try and find out whether produce has been grown using organic methods or synthetic fertilisers.

''Using special mass spectrometers we measure not only the level of carbon and nitrogen... but more importantly the ratio of heavy to light atoms. This determines the origin of the elements,'' said Dr. Rogers in an article recently submitted to Organic NZ magazine.

Dr. Rogers said synthetic nitrogen (fom synthetic fertilisers) is primarily made from light nitrogen, whereas recycled nitrogen (such as composts or animal manure) contains heavier nitrogen atoms.

She said her research currently has found no evidence of fraud in organic vegetable sample studies in New Zealand.

''All showed an enriched nitrogen isotope signature - typical of recycled nitrogen being taken up by the plant and transferred to the produce,'' she said.

While good for vegetables, one problem with the technique is that isotopes are unlikely to distinguish between legumes like peas and lucernes - ''which fix atmospheric nitrogen, and have similar nitrogen isotopes regardless of their growing regime'' says Dr. Rogers.

She said the technique could be used to encourage best practise producers, as well as providing a check point for buyers, with many distributors already sending in samples to test the authenticity of produce they are buying.

''Stable isotopes are carving an important niche for the possibility of screening produce,'' she said.

Isotopes have also been used to begin to identify whether eggs are from caged, or free-range and organic origins.

Using isotope analysis, Dr Rogers found almost all eggs could be differentiated by relating the carbon and nitrogen found in the egg to the hen's diet.

''Free-range and organically farmed hens normally have access to a wider range of food sources than caged hens, such as insects, vegetation or organic feeds, and this changes the isotope fingerprint of their eggs,'' she said.

Contact Dr. Karyne Rogers: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

FOR MORE INFORMATION
- Visit the international forum Organic Food Authentication - Challenge or Utopia? CLICK HERE
Registrations close October 24th;

- On research by Dr. Karyne Rogers visit: (vegetables) CLICK HERE
OR (eggs) CLICK HERE

This article has been adapted from the article: Is it organic? Prove it which appeared first in the September/ October edition of Organic NZ magazine.