Influence of lactic starter inoculation, curd heating and ripening temperature on Staphylococcus aureus behaviour in...

Growth and survival of Staphylococcus aureus were investigated in 52 lots of raw ewe's milk Manchego cheese manufactured and ripened under different conditions. A 5.8-fold reduction in S. aureus counts after 60 days of ripening was obtained by inoculating milk with 1% Streptococcus lactis culture, and a further 2.0-fold reduction could be achieved by adding 0.1% Lactobacillus plantarum culture. Curd heating temperature had a significant effect on S. aureus survival, with counts 4-5 times lower in cheese from 30 degrees C curd than in cheese from curd heated at 36-40 degrees C. Ripening temperature was the parameter with the greatest influence on S. aureus counts, which reached in cheese cured at 10 degrees C or 20 degrees C for 60 days levels 10 and 100 times lower, respectively, than in cheese held at 5 degrees C.