A Simple and Effective Mass Spectrometric Approach to Identify the Adulteration of the Mediterranean Diet Component Extra-Virgin Olive Oil with Corn Oil.

Francesco Di Girolamo,Andrea Masotti,Carlo Zambonin,Isabella Lante,Lorenza Putignani,Maurizio Muraca,Margherita Scapaticci,Cosima Calvano

doi:10.3390/ijms160920896

Abstract

Extra virgin olive oil (EVOO) with its nutraceutical characteristics substantially contributes as a major nutrient to the health benefit of the Mediterranean diet. Unfortunately, the adulteration of EVOO with less expensive oils (e.g., peanut and corn oils), has become one of the biggest source of agricultural fraud in the European Union, with important health implications for consumers, mainly due to the introduction of seed oil-derived allergens causing, especially in children, severe food allergy phenomena. In this regard, revealing adulterations of EVOO is of fundamental importance for health care and prevention reasons, especially in children. To this aim, effective analytical methods to assess EVOO purity are necessary. Here, we propose a simple, rapid, robust and very sensitive method for non-specialized mass spectrometric laboratory, based on the matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) coupled to unsupervised hierarchical clustering (UHC), principal component (PCA) and Pearson’s correlation analyses, to reveal corn oil (CO) adulterations in EVOO at very low levels (down to 0.5%).

Highlights

Extra virgin olive oil (EVOO) is a fat made by crushing olives and extracting the juice from theOlea europaea (i.e., Oleaceae family) a traditional tree crop of the Mediterranean region.Remarkably, EVOO represents the principal source of fat in the countries of the Mediterranean basin [1], historically associated with good health and longevity [2]
Our approach exploits the performance of linear MALDI-TOF MS, coupled to unsupervised hierarchical clustering (UHC), principal component (PCA) and Pearson’s correlation analyses, for the detection of CO adulteration in EVOO at very low levels, with the final aim of preserving the intrinsic nutrition value of such a fundamental MD food
Four independent MALDI-TOF MS lipid profiles from each EVOO and CO samples, were visually inspected and the resulting flattened spectra profiles compared by gel-like representations (Figure 1)

Summary

Introduction

Extra virgin olive oil (EVOO) is a fat made by crushing olives and extracting the juice from the. Our approach exploits the performance of linear MALDI-TOF MS, coupled to unsupervised hierarchical clustering (UHC), principal component (PCA) and Pearson’s correlation analyses, for the detection of CO adulteration in EVOO at very low levels (down to 0.5%), with the final aim of preserving the intrinsic nutrition value of such a fundamental MD food. To this aim, pure oil samples or binary mixtures containing EVOO with CO, were prepared according to Calvano et al [41], for selective polar lipid enrichment and direct analyses by MALDI-TOF MS

Results and Discussion

Experimental Section

Oil Sampling and Pre-Treatment

MALDI-TOF MS Spectra Acquisition

MALDI-TOF MS Spectra Analysis

Conclusions