Effect of heat treatment on Listeria monocytogenes and gram-negative bacteria in sheep, cow and goat milks.
Sheep milk, compared with cow and goat milk, had a protective effect on Gram-negative bacteria and Listeria spp. heated at 65 degrees C in a test-tube method. This effect was not solely due to fat content as cow milk artificially reconstituted to 10% homologous fat was not as protective. Listeria monocytogenes in whole sheep, cow and goat milks at an inoculum level of 1 x 10(6) cfu ml-1 was heated at 68 degrees C for 15 s in the plate pasteurizer and survival was only detected in whole sheep milk after heating. Whole sheep, cow and goat milks containing high levels of L. monocytogenes (1 x 10(6) cfu ml-1) could not survive the current HTST plate pasteurization protocol.
MacDonald
F
F
Hannah Research Institute, Ayr, Scotland, UK.
Sutherland
A D
AD
D000818:Animals; D015169:Colony Count, Microbial; D005223:Fats / Q000032:analysis; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D006041:Goats; D006090:Gram-Negative Bacteria / Q000254:growth & development* / Q000302:isolation & purification; D006358:Hot Temperature; D008087:Listeria / Q000254:growth & development / Q000302:isolation & purification; D008089:Listeria monocytogenes / Q000254:growth & development* / Q000302:isolation & purification; D008892:Milk / Q000737:chemistry / Q000382:microbiology*; D012756:Sheep; D013242:Sterilization / Q000379:methods; D013997:Time Factors
D005223:Fats