Pasteurization Lecture Notes

Introduction to Pasteurization

• Developed by Louis Pasteur in the 1860s.
• Initially developed to prevent spoilage of beer and wine.
• Commonly associated with dairy products like milk.

Purpose of Pasteurization

• Not a sterilizing technique.
• Two Key Functions:
  1. Kill pathogens.
  2. Reduce spoilage organisms.
• Aims to extend shelf life without greatly altering taste.
• Tradeoff: Killing microbes vs. maintaining product taste.

Types of Pasteurization

1. Stovetop Pasteurization

   • Traditional method.
   • 63°C (145°F) for 30 minutes.
   • Used, for example, in making yogurt.

2. HTST Pasteurization (High Temperature Short Time)

   • 72°C for 15 seconds.
   • Common modern practice.
   • Higher temperature reduces time needed.

3. UHT Pasteurization (Ultra-High Temperature)

   • 138°C for 2 to 4 seconds.
   • Extends shelf life to up to 90 days without refrigeration if properly sealed in sterile packaging.
   • Nearly sterilizes the milk.
   • Useful in situations with limited refrigeration (e.g., military bases, some countries like Germany).

Importance and Benefits

• Eliminates pathogens and spoilage organisms.
• Extends shelf life significantly.
• Organic products are often UHT pasteurized to extend shelf life since they sell slower and consumers prefer less processed products.

Conclusion

• Pasteurization is a crucial technique in food processing.
• Developed by Louis Pasteur, it is vital for food safety and extending the shelf life of perishable goods.
• Not a method of sterilization but effective in reducing harmful organisms while preserving taste.

The lecture was both informative and engaging. Looking forward to more classes in the future.