From cooking to cosmetics, the oil of the fruit of the argan tree is being exploited due to its reported pharmacological effects. As the argan tree is native to Morocco and the oil is recognised as a product of protected geographical origin, supply is limited.
The effect of these two factors has led to argan oil becoming one of the most expensive edible oils globally. This in turn results in an increase in economically motivated adulteration.
As a typical nut oil, argan oil comprises predominantly mixed triglycerides (TAGs). Based on previous work with both similar edible oils and meat speciation, benchtop NMR is proven to accurately determine authenticity through measurement of these TAGs.
Using several samples of argan oil of assured origin, a group of compositional parameters that distinguish authentic argan oil is determined. Using these parameters, a screening method has been developed to quickly identify authentic and adulterated argan oil. In tests on store-purchased argan oil, several were found to be fraudulent.
1H NMR spectra of pure argan oil, and two adulterated samples showing the clear spectral differences that allow rapid identification of adulterated argan oil using it’s fatty acid profile.