Metabolomic profiling and molecular characterization of food matrices: identification of potential markers of microbial contamination

The research aims to generate an early warning system able to highlight, in real time, bacterial contamination of meat matrices and to provide information which could support companies in accepting or rejecting batches. Current microorganisms detection methods rely on techniques (plate counting), which provide retrospective values for microbial contamination. The disposal of fast headspace air measurement, using gas chromatography-mass spectrometry analysis, able to accurately and rapidly (30 min per sample) detect microbial spoilage in raw meat, could result a valid replacement to traditional and time-consuming (3 to 4 days) standardized microbiological analysis required by regulations. The experiments focused on the qualitative and quantitative evaluation of volatile organic compounds (VOCs) produced by Salmonella Typhimurium, Campylobacter jejuni and Staphylococcus aureus in different types of raw meat (beef, pork, chicken). The reduction of analysis times represents the strength of the alternative method to ISO protocols, although these are currently the official procedures provided by International regulations. The applied method requires smaller sample aliquots and does not need any sample processing, thus consenting its application on different food matrices (not only meat) and for the detection of a wide variety of pathogens. The validation of the suggested analytical approach would therefore result innovative, by evaluating further samples in order to demonstrate the benefits of the technique in terms of times, costs and preservation of consumers health. Data analysis allowed the characterization of unique VOC profiles and possible marker compounds of meat contamination due to certain pathogens. The identification of marker volatile compounds resulted essential to outline specific metabolic profiles for each microorganism responsible of meat spoilage.