Metataxonomic signature of beef burger perishability depends on the meat origin prior grinding

Spoilage dynamics of two beef burger batches from different beef origins were followed from their shared processing run until the use-by date and beyond. Amplicon based sequencing of bacterial and fungal communities were compared with microbial counts and volatilome profile in order to determine whether and at which extent their perishability was related to the batch origin. Microbiological counts did not differ between batch A and B, whereas Volatile Organic Compounds (VOCs) profiles were only distinguishable after the use-by date. Metataxonomic analysis showed that both batches shared the same initial fungal and bacterial community, which however represented a transient signature of the processing run. Indeed, it was rapidly replaced by batch-autochthonous species of fungi and bacteria. Different temporal succession patterns of psychotropic lactic acid bacteria (LAB) were observed between the batches from the fourth day of vacuum storage. In particular, the sequential dominance of Carnobacterium divergens and Leuconostoc piscium in batch B was correlated with a more heterogeneous volatilome and greater production of VOCs linked to off-odours, such as the acetoin. The metataxonomic survey was able to discriminate between the two batches of hamburgers in relation to their origin and regardless of the initially shared processing-derived contamination.