Growth and survival of Escherichia coli O157:H7 during manufacture and storage of Indian cheese (paneer).
The growth and survival of Escherichia coli O157:H7 during manufacture and storage of Indian cheese or paneer was investigated. Pasteurized and raw milk that had been inoculated with 10(4) CFU/mL of E. coli O157:H7 cultures were used for manufacturing paneer samples which were vacuum-packaged and stored at 4 degrees C, 8 degrees C, and 28 degrees C. Survival and growth of E. coli O157:H7 in paneer samples was determined after every 4 h for up to 48 h. Escherichia coli O157:H7 could survive the manufacturing process of paneer and were present at the end of the storage period (at 28 degrees C) in significantly (p < 0.05) greater numbers than the initial inoculum. No significant difference in survival and growth were noticeable in paneer samples manufactured from raw milk. Though refrigeration (4 degrees C or 8 degrees C) effectively inhibited the growth of E. coli O157:H7, this pathogen could survive over a period of 48 h. Our observations suggest that unpasteurized or improperly pasteurized milk could be an important source for transmission of E. coli O157:H7 through paneer, and appropriate steps must be taken by government agencies to ensure consumer safety for this dairy product.
Wahi
Sidhi
S
Department of Biotechnology and Environmental Sciences, Thapar Institute of Engineering and Technology, Patiala, India.
Bansal
Sunita
S
Ghosh
Moushumi
M
Ganguli
Abhijit
A
D000818:Animals; D002611:Cheese / Q000382:microbiology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D019453:Escherichia coli O157 / Q000254:growth & development*; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D018857:Food Packaging / Q000379:methods*; D006801:Humans; D008892:Milk / Q000382:microbiology; D013696:Temperature; D013997:Time Factors; D014618:Vacuum