Quality control of honey, milk, and coffee by NMR-profiling

By Dr Eric Jamin, Eurofins Analytics France

Profiling by High-Resolution - Nuclear Magnetic Resonance is an innovative technique used for testing the authenticity of foodstuffs. With limited sample preparation followed by a single NMR analysis, this fast and high-throughput technique provides a wide range of information, both targeted (quantification of defined compounds) and non-targeted (identification of deviations from typical spectral patterns). As a result of the intensive collaborative research projects carried out in Eurofins laboratories, several new applications are now available, which significantly improve the state-of-the-art of authenticity testing. These include:

Honey authenticity screen

Improves the detection of sugar addition in honey, extending the detection to sugar syrups from C3-plants such as rice or wheat, which cannot be properly detected using the carbon 13 isotope AOAC method (focused on C4 plant sugars such as maize and cane). The combination of these two approaches allows detection of all possible sugar sources, at economic adulteration levels (5-10% and more). It simultaneously checks the declared botanical origin of the honey and provides an estimated level of the major components in honey, thus reducing the need for additional tests.

Milk and milk powder authenticity screen

Allows the detection of a wide range of potential adulterants such as melamine, dicyandiamide, protein hydrolysates or similar "nitrogen-level enhancers" added to artificially increase the apparent protein level, when used at economic adulteration levels (approx. 0.1% of milk proteins). The results can be used to check compliance and commercial product labelling in terms of animal species, fat content & sugar profile, thermal treatment, and microbial spoilage indicators (organic acids).

Coffee authenticity screen

Allows for a fast screening to differentiate between Arabica and Robusta varieties based on markers present in both, green and roasted coffee. Eurofins is continuing research towards extending the scope of NMR profiling to include other coffee authenticity criteria and will in the near future provide additional offerings using this technique.

Contact: ASMNantesAuthenticity@eurofins.com