A 1H NMR-based protocol for the detection of refined olive oil adulterations with refined hazelnut oil

Abstract

A 1H NMR analytical protocol for the detection of refined hazelnut oils in admixtures with refined olive oils is reported according to ISO format. The main purpose of this research activity is to suggest a novel analytical methodology easily usable by operators with a basic knowledge of the NMR spectroscopy. The protocol, developed on 92 oil samples of different origin within the European MEDEO project (Development and Assessment of Methods for the Detection of Adulteration of Olive Oil with Hazelnut Oil) (1,2), is based on 1H NMR measurements combined with a suitable statistical analysis. It was developed using a 600 MHz instrument and was tested by two independent laboratories on 600 MHz spectrometers allowing the detection down to 10% adulteration of olive oil with refined hazelnut oils. Finally, the potentiality and the limitations of the protocol applied on spectrometers operating at different magnetic fields i.e. at the proton frequency of 500 MHz and 400 MHz were investigated.