Question

What is the name of the process used to destroy pathogenic microorganisms in liquid foods using high heat for a short time?

• A. Sterilisation
• B. Pasteurisation
• C. Fermentation
• D. Dehydration

Hint:

Pasteurisation does not make food sterile; it only reduces microbial load to safe levels, which is why pasteurised products still require refrigeration.

Answer 1

The Correct Option is B

Concept: Pasteurisation is a thermal processing technique used to destroy pathogenic microorganisms in liquid foods such as milk, juice, and beverages. It involves heating the product to a specific temperature for a short period of time, followed by rapid cooling. The most common method is HTST (High Temperature Short Time) pasteurisation, typically carried out at around 72$^\circ$C for 15 seconds. This method ensures microbial safety while preserving the nutritional and sensory qualities of the food.
Step 1: Understand the objective of the process.
The goal is to:

• Destroy harmful (pathogenic) microorganisms
• Reduce spoilage organisms
• Maintain food quality and nutrients

Step 2: Differentiate from other processes.

• Sterilisation – destroys all microorganisms including spores (more intense heat)
• Pasteurisation – destroys mainly pathogens, not all spores
• Fermentation – uses microbes to produce food
• Dehydration – removes moisture to preserve food

Step 3: Identify the correct process.
Since the question specifies high heat for a short time in liquid foods, this clearly refers to pasteurisation, specifically the HTST method.