**1.1. Food quality and safety assessment**

Food quality and safety assessments are the main issues that modern food industries are required to fulfill in their production chains, being these properties directly correlated to the claims of a holistic nutrition representing the fundamentals of a healthy balanced diet. In the same direction goes, very recently, the need of checking the origin of an aliment even this is aspect is apparently not directly correlated to the main issues above presented.

All the steps of olive production chain require, as for any other food, a careful evaluation of the identity and absolute amounts of micro and macro components at the "molecular level".

Protect Denomination of Origin (P.D.O.), Protected Geographical Identification (I.G.P.) and other acronyms associated to olive oil quality, are often based on the apparent evaluation of macroscopic properties which hardly deals with a scientific approach to the problem, and whose official protocols of analysis lack often of the required specificity. A case study might be represented by the food safety incident worldwide known as *the melamine milk scandal*. Hundreds of babies fed with milk diluted with water and fraudulently treated with melamine to artificially increase the apparent protein content, developed kidney stones. Melamine is a plasticizer of molecular formula C3H6N6 thus with a nitrogen content equal to 67% of its molecular weight. The international official protocols for protein assay are still based on the two hundred years old Kjeldahl method, whereby the nitrogen content is evaluated from the amount of the released ammonia. This was the fate of melamine too! Exactly in the same period researchers from the University of Shangai have published a mass spectrometric assay of melamine in milk based on the specificity of isotope dilution method by means of a contemporary, reliable and affordable approach.1

The assessment of quality and safety of all the steps of a given food chain needs to be based on the exploitation of high-tech analytical methodologies. Mass spectrometry represents a

© 2012 Sindona and Taverna, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2012 Sindona and Taverna, licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

valuable tool widely applicable to the identification and assay of those quality markers present in olive oil.

Modern Methodologies to Assess the Olive Oil Quality 241

When minor compounds or active principles present in olive oil need to be identified the sample preparation usually requires simple extraction of the analytes followed usually by a direct injection into a multistep mass spectrometer (MS/MS). A case study is represented by the anti-inflammatory dialdehydes formed in olive oil by enzymatic degradation of

A simple check on the existence of these molecules in olive oil can be performed from the

The structure of many of the analytes present in the figure 1 was evaluated by further MS/MS experiments. The species at m/z 379, 414 and 428 were, than, associated to the protonated dialdehyde **4** (R= hydroxytyrosol, Scheme 1) and to the ammoniated species of the corresponding geminal diol and hemiacetal. The latter are expected reaction products of the very reactive system represented by the dialdehydes 3 and 4, when exposed to water and methanol interaction. The observed results could be considered as a remarkable case of *freezing* fast equilibrating species and detect them on-line, separately; the formation, however, of stable derivatives from a given analyte, present in a complex mixture such as olive oil, represents a *false positive* which can be eliminated by *selecting* a proper

The recently introduced MS ambient ionization methods6 are applicable to direct evaluation of complex food matrices such as olive oil. In this case too, especially in the assay of a

crude methanol extracts by means of LC-MS/ MS (Figure 1).4

**Figure 1.** LC-MS chromatogram of a methanol extract.

derivatization procedure as it will considered later.5

specific component, in situ derivatization may still be needed.7

secoiridoids (scheme 1).3
