Microbiological and physico-chemical changes in Genestoso cheese, a Spanish acid curd variety, throughout ripening

The aim of this work was to study the microbiological and physico-chemical changes in four batches of Genestoso cheese (two ripened in autumn–winter and the other two in spring–summer) throughout manufacture and ripening. In general, the pH decreased more quickly in the cheeses manufactured in spring which, moreover showed values lower in aw and higher in salt/moisture content. The highest counts of aerobic mesophilic bacteria, presumptive lactococci and presumptive leuconostoc were reached in 2 day old cheeses. Lactobacilli and fungic flora became predominant with ripening. The counts of enterococci differed between the batches, but in general the maximum counts in kanamycin aesculin azide were obtained after ripening for 2 or 7 days. The counts on mannitol salt agar were very low and disappeared in the first days of ripening. Enterobacteriaceae were not detected after 15 days of ripening in the cheeses manufactured in spring nor in the 7 day old cheeses of an autumn batch