Short communication: effect of homogenization on heat inactivation of Mycobacterium avium subspecies paratuberculosis in milk.
Mycobacterium avium ssp. paratuberculosis (MAP) can be present in cow milk and low numbers may survive high-temperature, short-time (HTST) pasteurization. Although HTST treatment leads to inactivation of at least 5 log10 cycles, it might become necessary to enhance the efficacy of HTST by additional treatments such as homogenization if the debate about the role of MAP in Crohn's disease of humans concludes that MAP is a zoonotic agent. This study aimed to determine whether disrupting the clumps of MAP in milk by homogenization during the heat treatment process would enhance the inactivation of MAP. We used HTST pasteurization in a continuous-flow pilot-plant pasteurizer and evaluated the effect of upstream, downstream, and in-hold homogenization on inactivation of MAP. Reduction of MAP at 72°C with a holding time of 28s was between 3.7 and 6.9 log10 cycles, with an overall mean of 5.5 log10 cycles. None of the 3 homogenization modes applied showed a statistically significant additional effect on the inactivation of MAP during HTST treatment.
Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institute, Federal Research Institute of Nutrition and Food, 24103 Kiel, Germany. Electronic address: philipp.hammer@mri.bund.de.
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Hammer
Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institute, Federal Research Institute of Nutrition and Food, 24103 Kiel, Germany.
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Kiesner
Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institute, Federal Research Institute of Nutrition and Food, 24103 Kiel, Germany.
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Walte
D000818:Animals; D002417:Cattle; D005260:Female; D005506:Food Contamination; D005516:Food Microbiology; D006358:Hot Temperature; D050296:Microbial Viability; D008892:Milk / Q000382:microbiology*; D016927:Mycobacterium avium subsp. paratuberculosis / Q000302:isolation & purification*; D061352:Pasteurization
Mycobacterium paratuberculosis; heat inactivation; homogenization; milk