NMR measurement of free and esterified sterols

This short account describes a novel analytical technique for the determination of total, free and esterified sterols in olive oil developed in our laboratory. This methodology is based on ¹H and ³¹P NMR spectroscopy. The latter spectroscopic analysis requires first the derivatization of the sterolic hydroxyl groups with a phosphitylating reagent. This NMR method shows a number of advantages over conventional methods for sterols determination, amongst which speed and simplicity are the most beneficial ones. The possibility of applying the NMR spectroscopy to other food matrices is discussed.