METROFOOD-IT Webinar: Techniques for Food Quality and Safety

Advanced techniques and methodologies used in research for the agri-food sector were the focus of the webinars organised by METROFOOD-IT that took place in the first week of February, with a large audience of mainly young researchers. The first event was led by Dr. Daniela Pontiggia, from the Sapienza University of Rome, on the topic of "Proteomic Principles and Techniques for the Improvement, Quality and Genuineness of Food Products".

During the webinar, a definition of omics sciences was first of all given: these are all those disciplines that use analysis technologies that allow the production of information (data), in very large numbers and in the same time interval, useful for the description and interpretation of the biological system studied. 

To the family of omics sciences belongs proteomics, which has to do with the study of the proteome: this term encompasses all proteins expressed at the same time in a cell at the same time, including all isoforms and forms carrying post-translational modifications. In fact, while the genome is constant for a given cell and identical for all the cells of an organism (and does not change much within the species), the proteome is dynamic over time, changing in response to external factors and differing substantially between different cell types.

This characteristic poses no small challenges: for proteins, identification and quantification analyses are more complex than those used for nucleic acids.  One of the major complications in proteomics experiments (particularly in differential proteomics) is being able to identify the least abundant proteins, which are often those whose concentrations vary upon stimulation.

During the webinar, it was highlighted that for proteins, Mass Spectrometry is used for identification and quantification. In this context, strategies are needed to reduce the complexity of protein mixtures to be analysed later by mass spectrometry. One possibility is the one-dimensional gel, from which single bands or slides can be taken if a specific band or a specific molecular weight protein number is to be identified.

Bioinformatics, i.e. the use of algorithms and software to analyse spectrometry data and access databases of protein or DNA sequences, also plays a key role.

The following webinar addressed a closely related topic: Dr. Gianfranco Diretto, ENEA researcher, spoke on 'Metabolomics approaches on food species of interest'.  During the live broadcast, it was explained how the concept of Metabolomics refers to the entire set of metabolites that each cell/tissue/organism is able to synthesise and accumulate at a given time (developmental stage, stress condition, technological treatment, etc.). Metabolites can instead be defined as chemical compounds, early, intermediate and final products of cell metabolism.

The result is that change in the metabolome is a direct consequence of changes in protein activity, which is not necessarily true of genomic, proteomic or transcriptomic changes. Indeed, diseases, environmental factors, drugs, etc., perturb the state of the metabolome by providing a system-wide view of the organism's or cell's response.

Dr. Diretto then spoke in detail about metabolic engineering, which is generally defined as a genetic engineering approach aimed at redirecting one or more enzymatic reactions to produce new compounds in an organism, improve the production of existing compounds, or mediate their degradation. Examples of enrichment of foods, such as tomatoes and potatoes, were presented during the webinar.

The third webinar in the first week of February was held (in English) by Dr. Nives Ogrinc, coordinator of METROFOOD-RI SLOVENIA, on the topic "Stable isotope metrology in food science." The starting point was a topic well known to the food industry: how can we fight against food fraud and be sure that the food we buy is authentic? One weapon in the fight is the use of stable isotopes, which can offer new possibilities for identifying food fraud. The use of this technique can make it possible to discover whether food is natural or synthetic, authentic or adulterated, as well as to obtain valuable information on geographical origin.

 She insisted that all stable isotope laboratories must be able to measure the same sample and obtain the same δ value within the analytical uncertainty. Furthermore, isotopic data measured with high precision but low accuracy must be normalised. Therefore, reference materials play a particularly important role in this context.

In summary, in the use of stable isotopes, particular attention must be paid to:

• Analytical techniques: details of sample preparation, type and mode of instruments, reagents
• Metrological traceability: use of reference materials (names, values and their uncertainties)
• Data handling: how measurement results were normalised to a stable isotope scale
• Uncertainty assessment: the uncertainty associated with a stated confidence level

Presentations of the described webinars are available below, and to register for the next ones, please go to this page.  Registration for METROFOOD-IT Webinars

Metabolomics approaches applied to agrifood species
Gianfranco Diretto - Biotechnology Unit, ENEA

Principi e tecniche proteomiche per il miglioramento, la qualità e la genuinità dei prodotti agroalimentari
Daniela Pontiggia - Dipartimento di Biologia e biotecnologie C. Darwin Sapienza