Authenticity, food chemometrics technique

Thousands of chemical compounds have been identified in oils and fats, although only a few hundred are used in authentication. This means that each object (food sample) may have a unique position in an abstract n-dimensional hyperspace. A concept that is difficult to interpret by analysts as a data matrix exceeding three features already poses a problem. The art of extracting chemically relevant information from data produced in chemical experiments by means of statistical and mathematical tools is called chemometrics. It is an indirect approach to the study of the effects of multivariate factors (or variables) and hidden patterns in complex sets of data. Chemometrics is routinely used for (a) exploring patterns of association in data, and (b) preparing and using multivariate classification models. The arrival of chemometrics techniques has allowed the quantitative as well as qualitative analysis of multivariate data and, in consequence, it has allowed the analysis and modelling of many different types of experiments. 

This chapter deals with the potentialities of chemometrics tools in resolving some real problems related to food traceability and authenticity. Since each chemometrics technique is widely explained in the previous chapters of the present book, only the application aspects are discussed in the present treatise. Particular attention will be paid only to the use of some exploratory, classification, and discrimination techniques. Moreover, all instrumental details are outside the aim of this chapter and will not be presented here. 

As far as the choice of a chemometrics technique to be used is concerned, it strongly depends on the aim of the investigation. In the authentication cmitext, the most general applications [16-21] are (i) characterisation of foodstuffs, (ii) discrimination or classification into one or several categories, (iii) monitoring and controlling of production processes, and (iv) identification of product adulteration, dilution, and contaminatiOTi. Wine is, by far, the food matrix for which chemometrics has been frequently caUed upon foUowed by cheese, oUve oil, honey, meat, and so on [27]. 

MCR is proven to be a very powerful tool for food analysis. The fact that this technique is devoted to analysing multicomponent systems matches optimally with the main aim of food studies, related to know the qualitative and quantitative composition of food. The plain results of MCR often provide the answer to the food problem, for instance, in analytical determinations or in process description, or may be a previous step to obtain fingerprint information that can be submitted to other chemometric tools for additional purposes, such as in authentication or classification problems. 

In the last decades, the interest of different researchers towards the use of analytical methodologies supporting the authenticity and traceability of food is ever-increasing. In particular, chemometrics tools combined with different analytical techniques are widely used to verify the authenticity of food. In the past two decades, a large number of contributions including numerous review articles and books dealing with quality and authenticity control have been published [11-26]. 

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