Thermal Inactivation of Foot-and-Mouth Disease Virus in Milk Using High-Temperature, Short-Time Pasteurization

• Published in: Journal of dairy science Vol. 90; no. 7; pp. 3202 - 3211
• Main Authors: Tomasula, P.M, Kozempel, M.F, Konstance, R.P, Gregg, D, Boettcher, S, Baxt, B, Rodriguez, L.L
• Format: Journal Article
• Language: English
• Published: Savoy, IL American Dairy Science Association 01.07.2007; Am Dairy Sci Assoc
• Subjects: Animal productions; Animals; Biological and medical sciences; Cattle; Cattle Diseases - prevention & control; Dairying - instrumentation; Dairying - methods; Fats; Female; Food Handling - instrumentation; Food Handling - methods; Food industries; food microbiology; food safety; foot-and-mouth disease; Foot-and-Mouth Disease - prevention & control; Foot-and-mouth disease virus; Foot-and-Mouth Disease Virus - physiology; Fundamental and applied biological sciences. Psychology; heat inactivation; high-temperature short-time pasteurization; Hot Temperature; Hydrogen-Ion Concentration; Male; microbial detection; Milk - chemistry; Milk - virology; Milk and cheese industries. Ice creams; milk quality; pasteurized milk; Terrestrial animal productions; Time Factors; Vertebrates; Virus; Disease; Dairy industry; Pasteurization; Dairy product; thermal inactivation; foot-and-mouth disease virus; High temperature; Inactivation; Milk
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2006-525

Previous studies of laboratory simulation of high temperature, short time pasteurization (HTST) to eliminate foot-and-mouth disease virus (FMDV) in milk have shown that the virus is not completely inactivated at the legal pasteurization minimum (71.7°C/15 s) but is inactivated in a flow apparatus at 148°C with holding times of 2 to 3 s. It was the intent of this study to determine whether HTST pasteurization conducted in a continuous-flow pasteurizer that simulates commercial operation would enhance FMDV inactivation in milk. Cows were inoculated in the mammary gland with the field strain of FMDV (01/UK). Infected raw whole milk and 2% milk were then pasteurized using an Arm-field pilot-scale, continuous-flow HTST pasteurizer equipped with a plate-and-frame heat exchanger and a holding tube. The milk samples, containing FMDV at levels of up to 10⁴ plaque-forming units/mL, were pasteurized at temperatures ranging from 72 to 95°C at holding times of either 18.6 or 36 s. Pasteurization decreased virus infectivity by 4 log₁₀ to undetectable levels in tissue culture. However, residual infectivity was still detectable for selected pasteurized milk samples, as shown by intramuscular and intradermal inoculation of milk into naïve steers. Although HTST pasteurization did not completely inactivate viral infectivity in whole and 2% milk, possibly because a fraction of the virus was protected by the milk fat and the casein proteins, it greatly reduced the risk of natural transmission of FMDV by milk.