Detecting food fraud in 45 minutes or less

Motivated by a need to help food regulatory authorities with detection of adulterated food products (products where certain ingredients are missing or replaced), University of Missouri scientist Colleen Ray and colleagues in the Department of Chemistry are now taking on the role of ‘food detective’ using their novel detection method.

The method uses nuclear magnetic resonance (NMR) spectroscopy to detect whether food products have been modified or adulterated with fillers like vegetable oil.

NMR spectroscopy uses a magnet and radio waves to determine the content and purity of different substances and has been used before with other food products like honey, olive oil and wine, according to C Michael Greenlief, Director of the MU Proteomics Center and Nuclear Magnetic Resonance Facility and corresponding author on the study.

“The analysis of food products with NMR spectroscopy is a powerful tool for the detection of adulteration,” said Greenlief, who is also a professor of chemistry. “It is ideal for analyses of this type due to a high sample throughout, the ability to discriminate based on structural differences of metabolites with similar masses and the ability to examine samples in either their native state or with little sample preparation.”

The scientists have created and tested a method to identify vegetable oil adulterants in hard cheese products. They discovered 29% of 52 samples of various non-refrigerated grated parmesan cheese were adulterated with palm oil, an ingredient that was not declared on the product labels.

University of Missouri scientist Colleen Ray loads samples into the NMR spectroscopy machine to be tested. Image credit: Pate McCuien/University of Missouri

“Genuine cheeses were found to have a very consistent lipid profile from sample to sample, improving the power of this approach to detect vegetable oil adulteration,” Ray said. “Palm oil itself is a clever adulterant owing to its semi-solid state at room temperature, similar colour to cheese and low price compared to cheese. However, this study is strictly limited to the lipid profile of these products, and no attempts were made to quantify any fillers aside from palm oil.”

The study, Detection of vegetable oil adulteration in pre-grated bovine hard cheeses via 1H NMR spectroscopy, has been published in the journal Molecules.

Top image credit: iStock.com/alle12