What is the standard HTST pasteurization condition used as a baseline in PMO?

• A. 145 F for 30 seconds
• B. 161 F for 15 seconds
• C. 172 F for 20 seconds
• D. 140 F for 60 seconds

Answer: (B)

The key idea is the standard HTST baseline used for pasteurizing milk in PMO: heating milk to 161°F (71.7°C) and holding for 15 seconds, followed by rapid cooling. This specific time–temperature combination is chosen because it reliably achieves the necessary reduction of pathogens (historically Coxiella burnetii is used as the reference organism) while preserving milk quality. It’s the baseline reference for HTST pasteurization in the PMO, and other methods are considered only as alternatives if they’re demonstrated to be equivalent in safety and approved by the regulations. The other options either use a holding temperature that isn’t the PMO baseline (lower or higher temps chosen for different processes) or don’t meet the established time–temperature standard, so they don’t serve as the PMO baseline.