Model Answer
0 min readIntroduction
Pasteurization is a heat treatment process applied to milk and other liquids to eliminate pathogenic microorganisms and reduce the number of spoilage organisms, thereby extending shelf life. It is a critical step in ensuring food safety and public health, particularly concerning market milk. The Food Safety and Standards Act, 2006, mandates pasteurization as a prerequisite for milk sale. While achieving microbial safety, pasteurization aims to preserve the nutritional qualities and sensory attributes of milk as much as possible. This answer will outline the different pasteurization procedures commonly employed in the dairy industry.
Pasteurization: An Overview
Pasteurization doesn’t sterilize milk; it reduces the microbial load to a safe level. The process relies on specific temperature and time combinations to achieve this.
Common Pasteurization Methods
Several methods are utilized for pasteurizing milk, each with its own operational characteristics:
1. High-Temperature Short-Time (HTST) Pasteurization
- Process: Milk is heated to 72°C (161°F) for 15 seconds.
- Advantages: Faster processing, minimal impact on flavor and vitamin content, widely adopted due to efficiency.
- Disadvantages: Requires precise temperature control, potential for alkaline reversion if not properly managed.
2. Low-Temperature Long-Time (LTLT) Pasteurization
- Process: Milk is heated to 63°C (145°F) for 30 minutes.
- Advantages: Historically common, believed by some to preserve flavor better than HTST (though this is debated).
- Disadvantages: Longer processing time, higher energy consumption, potential for greater impact on vitamin content (particularly vitamin C).
3. Batch Pasteurization
- Process: A small volume of milk is heated in a vat to 63°C (145°F) for 30 minutes, then cooled.
- Advantages: Suitable for small dairies or specialty products.
- Disadvantages: Slowest and least efficient method, higher labor costs, difficult to ensure uniformity.
| Method | Temperature (°C) | Time (minutes) | Advantages | Disadvantages |
|---|---|---|---|---|
| HTST | 72 | 0.25 | Fast, preserves flavor | Requires precise control |
| LTLT | 63 | 0.5 | Historically favored for flavor | Slow, higher energy use |
| Batch | 63 | 0.5 | Suitable for small dairies | Slow, labor intensive |
Quality Control
Stringent quality control measures are integral to pasteurization processes. These include:
- Regular temperature monitoring and recording.
- Flow diversion valves to redirect milk that doesn't reach the required temperature.
- Validation of pasteurization effectiveness through microbial testing (e.g., phosphatase test – indicating destruction of alkaline phosphatase, a bacterial enzyme).
- Calibration of equipment according to FSSAI guidelines.
Conclusion
In conclusion, pasteurization is a vital process for ensuring the safety and quality of market milk. While HTST is the dominant method due to its efficiency, LTLT and batch pasteurization still hold relevance in certain contexts. Adherence to established protocols, rigorous quality control, and continuous technological advancements are crucial for maintaining consumer trust and upholding the standards mandated by food safety regulations like the Food Safety and Standards Act, 2006. Future advancements may focus on non-thermal pasteurization techniques like high-pressure processing.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.