Fraudulent honey tests – the sticking point

Testing the authenticity of honey is easy; All you need is a glass of water, a match, or your thumb. At least that’s what popular opinion will have you believe…

The extent of recent media coverage in Australia says otherwise. From homemade purity tests to NMR, chemical profiling or the C4 sugar test, the method and accuracy of honey tests (as well as the bodies administering them) are causing a lot of disruption in the media – not to mention the results.

But the answer may not lie in the tests, nor the product, but the practice.

 The most recent publication (Scientific Reports, Zhou et al.) covers a market survey of over 100 honey samples from global sources (focusing on Australia) using two approaches – the ‘C4 sugar test’ and origin verification through chemical profiling. Both of which test naturally occurring properties within the honey, derived from the plants the bees pollinate.

The C4 sugar test is an effective way to determine if honey adulteration has occurred through the addition of sugarcane or corn syrup because genuine nectar has more negative carbon isotope values compared to honey adulterated in this way.

Manūka honey, on the other hand, is a little more complicated due to its chemical components and hive management practices, typically showing a higher C4 value than a comparative hive residing on pasture (i.e. clover).

Hive management, however, has a far larger role to play and one typically overlooked by most media coverage. Beekeepers typically keep their hives active prior to nectar flow and during poor weather (i.e. rain/wind) by feeding them with sugar water (i.e. a C4 sugar source). This C4 source substitute then finds its way into hive production in conjunction with the natural sector source. For the Australian and NZ derived honey in the publication, this is the most likely source of the higher C4 levels – not the blending of the final product.

 Further complicating matters, C3 plants are also refined for their sugar source (rice, sugarbeet etc.), and this has been one of the shortcomings of the C4 method: it is possible to use C3 sugar to adulterate honey by bulking it out and this would go undetected by the standard isotope test.

This is where the work also reported recently from a German lab comes into play. The new method using NMR (an MRI for sample testing) can detect these forms of alteration by looking at the hydrogen component of the sugars rather than the carbon, proving several honeys from Australia to be adulterated in this way.

 The later part of the study utilises chemical profiling as a method to verify the origin of the honey tested – an approach related to the methodology we employ here at Oritain.

Chemical profiling analyses the presence and abundance of trace elements and isotopes to determine the product’s origin. Both indicators are influenced by the geochemistry of the environment and provide an incredibly robust verification of origin – interpreted at Oritain through complicated multi-variate statistical models that provide a more accessible ‘fingerprint of origin’.

Once this fingerprint is established, we conduct testing at various points in the supply chain, comparing the new samples to the original fingerprint of origin. An inconsistent match implies origin adulteration of some kind. Where other tests falter, Oritain’s forensic science approach matches back to the unique geochemical profile of the product’s origin, providing complete assurance to both producer and consumer.

 In a market where brand reputation, quality and origin are so intrinsically linked, having confidence in the authenticity of your product – and being able to pass this onto consumers – is vital. And having robust, proven science underpinning these claims should no longer be considered a luxury. It’s not enough to rely on a glass of water, a matchstick, or your thumb.

 (See full length article here).