Microbial communities and volatile profile of Queijo de Azeitão PDO cheese, a traditional Mediterranean thistle-curdled cheese from Portugal

The production of ovine or caprine milk cheeses with thistle rennet is a common practice in the Mediterranean basin. aim present study was to obtain information on bacteria and yeast communities harboured by Queijo de Azeitão PDO cheese through viable counting and, for first time, via metataxonomic analysis. Moreover, solid phase microextraction (SPME) technique applied characterize volatile compounds. Nine samples were collected from three different artisan producers located Portugal. results physico-chemical analyses showed significant differences between producers, mean values ranging 5.40 ± 0.25 (Producer 1) 6.00 0.22 2). As TTA, Producer 1 highest value attesting at 18.04 6.57 mL 0.1 M NaOH used reach pH 8.3. Regarding lactic acid concentration, 0.488 0.106 g 100 g−1, whereas, acetic acid, no evidenced among comprised 0.141 0.021 g−1 0.245 0.016 g−1. No observed overall counts presumptive lactococci, thermophilic cocci, lactobacilli, lactobacilli total mesophilic aerobes order 7–8 log cfu coagulase-negative enterococci, Enterobacteriaceae Pseudomonadaceae. eumycetes, lowest (2.78 2.42 g−1) respect detected 2 3. Concerning microbiota mycobiota analyzed cheeses, alpha diversity index did not show any difference terms composition complexity microbial population. A simple apparently shared whose manufactures dominated presence Leuconostoc mesenteroides (37% relative frequency average), Lactococcus lactis (29%), Lacticaseibacillus zeae (4.7%), Lentilactobacillus kefiri (4.4%), Serratia spp. (3.5%), Lactiplantibacillus plantarum (2.7%), Latilactobacillus sakei (2.5%). neat dominance Yarrowia lipolytica (46.7% followed Candida ethanolica (13.6%), Kurtzmaniella zeylanoides (9.4%), Geotrichum candidum (8.8%), Galactomyces geotrichum (8.7%), Kluyveromyces silvicola (2.7%). profile analysis allowed 24 compounds be identified: 7 acids, esters, 4 alcohols, 3 ketones, aromatic hydrocarbons, aldehyde. most represented organic (VOCs) 2-butanone, butanoic hexanoic acid. positive correlation Len. isopentyl isobutyrate (P < 0.05), whereas Y. displayed number correlations 3-methyl-butanal, 2-pentanone 2-pentanol 0.05). To authors' knowledge, this very detection raw ewe’s coagulated vegetable rennet.