1. [Recovery of Staphylococcus aureus after acid injury in milk products].
- Author
-
Assis EM, De Carvalho EP, Asquieri ER, and Robbs PG
- Subjects
- Animals, Cattle, Food Preservation, Hydrogen-Ion Concentration, Staphylococcal Food Poisoning prevention & control, Staphylococcus aureus growth & development, Cheese microbiology, Staphylococcus aureus isolation & purification, Yogurt microbiology
- Abstract
The growth behavior of Staphylococcus aureus in fresh Cheese (Minas and Muzzarella) during their shelf-life was studied. The possible injury of this microorganism caused by the increasing acidity was also investigated. Raw milk was inoculated with 10(6) cells/ml (S. aureus FRIA-100) and the cheese production was performed according to normal procedures. Minas and muzzarella cheese were stored at 7 degrees C for 40 and 60 days, respectively. At 2-3 days intervals, the following analysis were performed: acidity, pH, S. aureus counting using agar Baird Parker by the traditional methods and by the method recommended by the American Public Health Association to evaluate the reparation of injured cells. We had a secure indication of the presence of injured S. aureus when acidity was in the range of 0.7 to 0.8% expressed in lactic acid and when the cycle was 1.3 log higher than the traditional one.
- Published
- 1994