Food fraud study: handheld near infrared spectroscopy wins again

Studies have already shown NIR to be effective in detecting food fraud in Basmati rice and almonds, both potential targets for fraudsters.

Now a fresh paper authored by Terry McGrath, working with ASSET Technology Centre, Institute for Global Food Security at Queen's University Belfast has indicated promising results from oregano samples. A low-cost, handheld NIR single device chemometric model was used to test the samples in the inter-laboratory study involving 27 participants from 22 countries using 34 unique devices.

What makes the approach so interesting is that it could be potentially be used in a factory setting to deliver extremely rapid results.

All adulterated samples correctly predicted

Participants correctly predicted more than 98% genuine oregano after device standardisation and 100% of adulterated samples after standardisation.

Results showed more than 85% correlation compared to Fourier Transform Infrared technology conforming to the ISO 17,025 spectroscopy standard.

Fraud in the food supply system would be exacerbated by shortages caused by climate change and COVID-19′s impact and the complex dried herbs supply chain was financially attractive to fraudsters, the study abstract states.

'Real-time remote testing achievable'

"Real-time remote testing is achievable through development of globally accessible chemometric models for portable near infrared devices, deployed throughout supply chains," it continues.

"33/34 portable devices were able to correctly classify five out of six samples successfully with all adulterated samples being correctly classified following the use of appropriate transferability pre-processing routines.

"The device's native setup shows limited ability to perform a true screening of oregano using the setup offered. However modifications to the setup could in the future offer a solution that facilitates fit-for-purpose real time detection of adulterated samples within the supply chain."

Studies on adulteration of almonds and Basmati rice

Meanwhile, research published in the journal Talanta led by professor Chris Elliott of the Institute for Global Food Security at Queen's University Belfast indicated near 100% accuracy in detecting adulteration of Basmati rice. Real-time tests of samples using handheld NIR spectroscopy devices at production sites were found to be 90% accurate. A second type of lab-based test using gas chromotography mass spectrometry gave almost 100% precision from the nearly 1,400 samples.

Research by Farming Systems Engineering and Food Technology research groups at the University of Cordoba’s School of Agricultural and Forestry Engineering in Spain in collaboration with the Andalusian Institute of Agricultural Research and Training’s Alameda del Obispo Center detected 90% of sweet almonds adulterated with bitter almonds using similar technology. The study was published in the journal Food Engineering.