What are food fingerprints?

In recent years, food frauds and adulterations have increased significantly. This practice is motivated by vast economical gains and has an enormous impact on public health.

Food fingerprints

Food fingerprints can be defined as molecular markers that represent a characteristic food state or condition, allowing more effective product discrimination.

Essentially, it is a marker or set of markers that allow us to answer many questions about food authenticity, such as “Are those organic carrots truly organic? Does this saffron really originate from Spain?

Targeted and untargeted methods

In food authentication field, there are targeted and untargeted methods of analysis.

The first approach focuses on the analysis of a specific metabolite or group of metabolites, while in the untargeted approach, the major goal is discrimination of patterns of metabolites that may change in response to environmental, genetic or human alterations (adulteration).

In this context, application of metabolomics to food science for assessing safety and authenticity has gained much interest.

Metabolomics studies are mainly discriminative and predictive, aiming to find differences between samples (e.g., for the oranges origin discrimination, for the variety and vintage differentiation of wines or for the civet coffees authentication) and to create statistical models to predict class memberships (e.g., for the classification of green coffee beans or wines according to botanical and geographical origins).

Obtaining food fingerprints

Food fingerprints may be obtained for food quality, safety and authenticity purposes. To achieve this, an experimental design should be carefully established, being the sample preparation and the analytical platforms selected critical parameters to evaluate.

A wide range of instrumental techniques, such as chromatography (gas and liquid), mass spectrometry or spectroscopy is used to monitor food authenticity and safety.

In particular, mass spectrometry approaches are popular due to its ability to distinguish small differences between samples in complex matrices.

In contrast, the development of spectroscopy and spectro fluorimetry methods may be related with their non-destructive nature, which is very relevant for expensive samples.

Other analytical strategies, as stable isotope and DNA analysis, are being also applied routinely for food authenticity purposes.

Food biomarkers

Compounds such as aminoacids, phenolic compounds, organic acids and volatile organic compounds of different chemical classes are the potential biomarkers for food authentication most often reported.

As these compounds possess different physicochemical properties, several analytical platforms must be employed to obtain reliable methodologies to detect and quantify biomarkers able to certify food stuffs origin, variety or production system, as well as to detect food adulteration or spoilage/freshness indicators.