Chromatographic and Related Separation Techniques in Food Integrity and Authenticity

The following sections are included:

• Preface
• About the Editors
• Contents

Society’s interest in relation to the authenticity and quality of food is increasing. Quality is among the most valued features when choosing food for purchase; however, its objective description is a very challenging task. This is because the amount and type of ingredients influence the quality of food. Within this context, the labeling of food products becomes essential to inform consumers about what kind of products they are buying. Also, this is practically the only tool that consumers have in order to assess the quality of food and select the products they consume. However, considering that we are in a globalized world, and the great complexity that this entails in the food chain, where there are a large number of people and factors involved from the production of a product to its final consumption, rigorous controls are demanded by society to guarantee the integrity and authenticity of food and to avoid fraudulent practices. Fraud in the context of food means that the description of the origin of food, its composition, and how it has been obtained and/or prepared, shall be truthful, i.e., nothing of lesser economic value must be added or removed if it is of higher economic value. If food is misdescribed, i.e., the information about origin, composition, etc., provided to customers is not true, and if this misdescription is done with the intention to deceive the customer for financial gain, food fraud (also known as economically motivated adulteration) is committed. In this chapter, different aspects regarding the current context of food integrity, authenticity, and frauds will be addressed.

Food authenticity and traceability is of great importance for many people, establishments, and food producers, consumers, and scientific communities and organizations. In the recent years, the food consumers have been demanding additional authenticity information regarding where their food products derive from; thus, there is a necessity for methodical systems that are competent enough to offer information on problems, such as food origins and their authenticity and traceability. Among the many methodical systems, the liquid chromatography–mass spectrometry (LC-MS) technique has massive potential in this area of food integrity and authenticity. In this chapter, we will illustrate that LC-MS is competent for practical application in an extensive group of food products, producing information on main food constituents. This information could be applied to identify the natural and/or synthetic food components. Consequently, LC-MS is considered one of the most powerful, influential analytical systems to identify the duplicitous and illegitimate constituents added in by the food manufacturing industries. The use of this technique will guarantee that customers have assurance in obtaining trustworthy foodstuffs. The use of LC-MS techniques for authenticity assessments and traceability will be considered.

Gas chromatography coupled with mass spectrometry (GC-MS) has extensive applications for food characterization and authentication. Due to the high thermal stability of lipophilic compounds, GC/MS lipidomic profiling of foods is a powerful approach for food authentication and characterization. Moreover, GC/MS volatilomic is a tool to discriminate samples in groups and identify specific biomarkers that are crucial for quality and/or authenticity assessment. The volatile organic compounds (VOCs) in food, especially in honey, wine, and olive oil, are being widely assessed by using GC-MS coupled with solid-phase microextraction (SPME). This chapter gives an overview of the applications of GC-MS lipidomic (fatty acids, triacylglycerols, phytosterols, and n-alkanes) and volatilomic profiling, which has powerful applications in food characterization and authentication.

Food integrity and authenticity are terms that simply refer to whether the food purchased by the consumer matches its description. However, due to the globalized food chain, false description of a foodstuff may happen in many forms, from the undeclared addition of cheaper materials, the wrong declaration of the amount of particular ingredients in the final product, or the making of false statements about the source of the ingredients, such as their geographic, plant, or animal origin. In addition, today, many consumers are prepared to pay more for products they consider to be of higher quality, which can be related to the manner of production (i.e., organic produced foods), or other reasons such as the geographical origin of a product, giving space for an increase in fraudulent practices for the seller’s economic gain. In the present chapter, the role of capillary electrophoresis (CE) techniques, a family of related separation techniques in which an electric field is used to achieve the separation of components in a mixture, to address food integrity and authenticity will be reviewed. Coverage of all kind of applications is beyond the scope of the present contribution, so the present chapter focus will mostly be on the most relevant applications published in the last years.

A wide variety of instrumentation and methods are used to determine volatile substances in different food samples, but most of them require complex pre-processing and multiple organic reagents, which are harmful to the environment. Nowadays, ion mobility spectrometry (IMS), with no complex pre-treatment and high sensitivity could be considered as a well-regarded technique for food analysis. Notice that IMS is a very well-known technique to detect explosives or drugs in security areas such as airports, and there are some devices based on IMS which give a quick answer, making it a useful sensor. Moreover, IMS has been coupled to MS to increase its resolution and discrimination power. The popularity of IMS has increased exponentially during the last 10 years, although it remains a completely unknown technique in agri-food laboratories. Due to the potential of this technique in this field, in this chapter its mechanism, current applications and prospects will be discussed.

Food authentication has become an issue of great interest for consumers, the food industry, regulatory authorities, as well as the scientific community, because of the substantial grown of food fraud in the past years. Historically, the detection of fraudulent practices has been based on the use of targeted methods, focusing on the quantification of primary markers, directly linked to the authenticity problematic. Nevertheless, nowadays this strategy is in some cases insufficient because of the huge number of adulterant substances that can potentially be added in food as well as the increase of complex food authentication issues (e.g., deception on the geographical origin or production method). As an alternative, non-targeted methods, consisting of the analysis of instrumental responses without assuming any previous knowledge about the sample composition, have gained relevance when combined with chemometrics. The present chapter examines the role of thin-layer chromatography (TLC) and liquid chromatography (LC) fingerprinting methodologies, usually combined with chemometric techniques, to guarantee food authenticity. In the case of LC, fingerprints obtained either by conventional detection systems or high-resolution mass spectrometry (HRMS) are discussed.

This chapter deals with the assessment of food integrity and authenticity by using chemometric methods. The principal analytical platforms for the generation of suitable descriptors of food samples, including chromatographic and spectroscopic methods, will be introduced. Depending on the cases, targeted or untargeted approaches based on compositional profiles or instrumental fingerprints will results in rich sources of information. The huge amount of data obtained in this way will be treated with chemometric methods to carry out exploratory sample characterizations, detection of adulterated products, and quantification of adulteration percentages.

The following section is included:

• Index