The detection of adulteration of olive oil with various vegetable oils – A case study using high-resolution 700 MHz NMR spectroscopy coupled with multivariate data analysis

Olive oil, being very salubrious, is one of the main ingredients of the Mediterranean diet. However, high oil prices combined with high consumption have increasingly subjected olive oils to fraudulent practices. The large rise in numbers of producers engaging in this illicit practice has made it necessary to develop a swift, convenient, and consistent analytical methodology to detect adulterating oil products and ensure product quality. In this study, we have merged multivariate statistical analysis with one-dimensional (1D) 700 MHz ¹H nuclear magnetic resonance (NMR) to analyze different types of vegetable and olive oil. Additionally, we have spiked virgin olive oil with varying percentages (1%–75% (v/v)) of other vegetable oils to obtain the spectra of adulterated olive oil. As a result, the method applied in our study can not only detect adulterated olive oils but also identify mixed adulterants. Ease of sample preparation, quick sample analysis, and straightforward data comprehension distinguishes this method from the currently published ones.