HTST Pasteurization Protocol

Temperature-time protocol for HTST pasteurization is:

Correct Answer: 72°C / 15 seconds

HTST (High Temperature Short Time) pasteurization, also called Flash pasteurization, uses 72°C for 15 seconds. It is the modern commercial method of pasteurization.

All Pasteurization Methods at a Glance

• LTLT (Low Temperature Long Time / Batch / Holding): 63°C / 30 minutes
• HTST (Flash pasteurization): 72°C / 15 seconds ✔
• Stassanization: 74°C / 7 seconds
• UHT (Ultra High Temperature): 130–135°C / fraction of a second
• Uperization (Ultra-pasteurization): 150°C / fraction of a second
• Vacuum pasteurization (Vacreation): by Vacreator using direct steam under reduced pressure

Key Points on HTST

• HTST is the most widely used method at commercial/industrial level.
• Index organism for pasteurization is Coxiella burnetti (causative agent of Q-fever) — it is the most heat-resistant pathogen destroyed by pasteurization.
• Phosphatase enzyme (naturally present in raw milk) is completely destroyed by pasteurization — hence the Phosphatase test is used to detect inadequacy of pasteurization.

Why Other Options Are Wrong

• 63°C / 30 min → LTLT method, not HTST.
• 72°C / 7 sec → Incorrect time; HTST requires 15 seconds at 72°C.
• 74°C / 7 sec → That is Stassanization, not HTST.