New tests to detect fake honey

International researchers have developed new tests to detect sugar syrup adulteration in honey.

A project led by Cranfield University, with the Food Standards Agency and the UK’s Science and Technology Facilities Council (STFC), used a specialist light analysis technique to detect fake honey without opening the jar.

The team used non-invasive spatial offset Raman spectroscopy (SORS) — more commonly used in pharmaceutical and security diagnostics — to test UK honey spiked with rice and sugar beet syrups.

The test is said to have rapidly identified the ‘fingerprint’ of each ingredient in the product. The scientists combined this technique with machine learning to successfully detect and identify sugar syrups from various plant sources.

The method is reportedly portable and easy to implement, making it a suitable screening tool for testing honey along the supply chain.

Cranfield University’s Dr Maria Anastasiadi, who led the project, said, “Honey is expensive and in demand — and can be targeted by fraudsters, which leaves genuine suppliers out of pocket and undermines consumers’ trust. This method is an effective, quick tool to identify suspicious samples of honey, helping the industry to protect consumers and verify supply chains.”

Another project, in collaboration with the Food Standards Agency and the Institute for Global Food Security at Queen’s University Belfast, used DNA barcoding to detect rice and corn syrups spiked in UK honey samples.

Scientists used 17 honey samples collected from bee farmers around the UK — across different seasons and a variety of floral nectar sources — and bought four samples of UK honey from supermarkets and online retailers. The samples were then spiked with corn and rice syrups produced in a range of countries.

DNA barcoding — a method already used in food authentication to identify plant species in products — was found to be effective in breaking down the composition of each sample to successfully detect syrups even at 1% adulteration level.

“To date, DNA methods haven’t been widely used to examine honey authenticity,” Anastasiadi said.

“But our study showed that this is a sensitive, reliable and robust way to detect adulteration and confirm the origins of syrups added to the honey.

“The large variation of honey composition makes it particularly difficult to authenticate. So having this consistent technique in the testing armoury could take the sting out of honey fraud.”

Sophie Dodd, who is completing her PhD on the topic of honey authentication at Cranfield University, said, “It is vital to have samples of known origin and purity to validate the methods, so we want to extend our thanks to the Bee Farmers Association who we work closely with in our projects.”

The two methods developed can work together to increase chances of detecting exogenous sugar adulteration in honey, according to the researchers.

Image credit: iStock.com/NATALIA MARNA