G Spano1, E Goffredo, L Beneduce, D Tarantino, A Dupuy, S Massa. 1. Institute of Alimentary Productions and Technologies, Agricultural Faculty, Foggia University, Institute Zooprofilattico of Apulia and Basilicata, Foggia, Italy.
Abstract
AIMS: The fate of Escherichia coli O157:H7 was investigated during the manufacture of Mozzarella cheese. METHODS AND RESULTS: The Mozzarella cheese was made from unpasteurized milk which was inoculated to contain ca 10(5) cfu ml(-1)E. coli O157:H7. Two different heating temperatures (70 and 80 degrees C), commonly used during curd stretching, were investigated to determine their effects on the viability of E. coli O157:H7 in Mozzarella cheese. Stretching at 80 degrees C for 5 min resulted in the loss of culturability of E. coli O157:H7 strains, whereas stretching at 70 degrees C reduced the number of culturable E. coli O157:H7 by a factor of 10. CONCLUSIONS: The results show that stretching curd at 80 degrees C for 5 min is effective in controlling E. coli O157:H7 during the production of Mozzarella cheese. Brining and storage at 4 degrees C for 12 h was less effective than the stretching. SIGNIFICANCE AND IMPACT OF THE STUDY: Mozzarella cheese should be free of E. coli O157:H7 only if temperatures higher than or equal to 80 degrees C are used during milk processing.
AIMS: The fate of Escherichia coli O157:H7 was investigated during the manufacture of Mozzarella cheese. METHODS AND RESULTS: The Mozzarella cheese was made from unpasteurized milk which was inoculated to contain ca 10(5) cfu ml(-1)E. coli O157:H7. Two different heating temperatures (70 and 80 degrees C), commonly used during curd stretching, were investigated to determine their effects on the viability of E. coli O157:H7 in Mozzarella cheese. Stretching at 80 degrees C for 5 min resulted in the loss of culturability of E. coli O157:H7 strains, whereas stretching at 70 degrees C reduced the number of culturable E. coli O157:H7 by a factor of 10. CONCLUSIONS: The results show that stretching curd at 80 degrees C for 5 min is effective in controlling E. coli O157:H7 during the production of Mozzarella cheese. Brining and storage at 4 degrees C for 12 h was less effective than the stretching. SIGNIFICANCE AND IMPACT OF THE STUDY: Mozzarella cheese should be free of E. coli O157:H7 only if temperatures higher than or equal to 80 degrees C are used during milk processing.
Authors: Elena Cosciani-Cunico; Elena Dalzini; Stefano D'Amico; Chiara Sfameni; Barbara Bertasi; Marina Nadia Losio; Federica Giacometti; Paolo Daminelli Journal: Ital J Food Saf Date: 2014-02-04