Unfolding microbiota and volatile organic compounds of Portuguese Painho de Porco Preto fermented sausages

In the present study, bacterial and fungal diversity, as well as volatile profiles, of ready-to-eat Portuguese Painhode Porco Preto fermented sausages manufactured by two artisanal producers in the districts of Beja (producer A)and Evora (producer B) were studied. To this end, different selective growth media and a metataxonomic analysiswere combined with Headspace Solid-Phase Microextraction-Gas Chromatography/Mass Spectrometry (HSSPME-GC/MS) analysis. The results of the microbiological viable counts revealed active microbial populations oflactic acid bacteria (up to 8 Log cfu g 1), coagulase negative cocci (up to 6 Log cfu g 1), and eumycetes (up to 6Log cfu g 1). Bacterial populations were characterized by high relative frequencies of Latilactobacillus sakei (up to72%), together with Weissella and Staphylococcus equorum. The mycobiota was mainly dominated by Debaryomyceshansenii (up to 55% of the relative frequency) and Kurtzmaniella zeylanoides (up to 24% of the relativefrequency). Unexpected species as Wickerhamomyces subpelliculosus and Zygosaccharomyces rouxii were alsodetected. HS-SPME-GC/MS analysis allowed to identify a complex volatile profile, showing 159 volatile organiccompounds (VOCs). VOCs belonged to twelve classes, such as aldehydes, ketones and lactones, esters and acetates,alcohols, terpenoids, sulfur compounds, aliphatic hydrocarbons, aromatic hydrocarbons, nitrogen compounds,acids, furans and pyrans, and phenols. The analysis of VOCs composition provided evidence that samplesfrom the two producers (A and B) were different, as confirmed by the Principal Component Analysis. Hence, it islikely that the raw materials used, as well as variations related with the empirical practice of the butchers,strongly influenced the final product. The results obtained in the present study represent a further advancementin the knowledge on the biodiversity and VOCs composition of Portuguese fermented sausages. To better understandthe interactions occurring between the autochthonous microorganisms and the meat batter in thePainho de Porco Preto fermented sausage, microbial and VOCs dynamics must be further deepened throughout theproduction process.