Microbiological and chemical profiles of naturally fermented table olives and brines from different Italian cultivars.

Six naturally fermented Greek-style)table olives of cultivars Itrana, Peranzana, Cellina di Nardo`, Nocellara del Belice and Bella di Cerignola, as well as their corresponding brines, were studied by a combined strategy consisting of chemical, microbiological and molecular analyses. In particular, organic acids, sugars, polyphenols, fatty acids, biogenicamines and cultivable microbiota were detected bystandard methods. Moreover, tyramine and histamineproducing bacteria were evaluated by an originalapproach consisting of Reverse-Transcription (RT)-qPCR. At the end of the fermentation process,mesophilic lactobacilli and yeasts in brine representedthe dominating biota, ranging from 6.25 to 7.84 log CFU/ml and from 6.5 to 7.56 log CFU/ml, respectively. Enterobacteriaceae and pathogens were undetectable in all the samples. In general, table olive preparations differed in chemical composition. Inparticular, C16:0 and C18:2c9,12 concentrationsranged from 9.9 to 18.8 % and from 5.4 to 15.4 % of total fatty acids, respectively. The main fatty aciddetected was C18:1c9 while CLAc9, t11 was present only in traces. Polyphenol concentrations greatlydifferentiated the final product, depending on thecultivar. A low quantity of biogenic amines was foundin some samples and biogenic amines producingbacteria were rapidly detectable by RT-qPCR.[...]