The origin of pasteurization
Pasteurization has a rich history, dating back to 19th-century France. Back then, the French brewing industry grappled with a serious issue: beer turning sour post-brewing, rendering it undrinkable. After extensive research, the renowned microbiologist and chemist Louis Pasteur (1822-1895) discovered the culprit – Lactobacillus.
Pasteur embarked on trials, experimenting with various temperatures to eradicate Lactobacillus from beer without altering its essence. Through meticulous efforts, he discovered that a 30-minute heat treatment at 50-60°C efficiently destroyed the culprit, preserving beer’s flavor and quality.
Consequently, pasteurization was named in honor of Pasteur, and its innovative heating process has emerged as a crucial technology in food processing and preservation.
Principles
Pasteurization, a common heat treatment, utilizes low temperatures to eliminate or slow down bacteria, yeasts, and other microbes in food. It works by harnessing pathogens’ heat sensitivity. Temperatures used are typically 60-85°C, held for seconds to minutes, tailored to food type and sterilization goals.
Applications
Pasteurization is a widely employed technique in the preservation of liquid food products, such as dairy products, fruit and vegetable juices, beers, wines, and more. In the realm of dairy processing, it serves to extend the shelf life while ensuring the safety of milk-based products like yogurt, milkshakes, etc., even in the absence of refrigeration. Similarly, other consumables including juices, condiments, sauces, alcoholic beverages, soups as well as canned goods undergo pasteurization to guarantee both their safety and quality.
Advantages
- Nutrient and Flavor Preservation： Pasteurization kills most harmful microorganisms while preserving the nutritional content and natural flavor of the food. For heat-sensitive foods like milk and juice, pasteurization reduces damage to their texture and nutrients, keeping the products closer to their fresh state.
- Low-Temperature Treatment： Compared to high-temperature sterilization, pasteurization uses relatively lower temperatures (usually below 100°C), minimizing damage to the food’s structure and nutrients, which is beneficial for maintaining nutritional value and taste.
- Extended Shelf Life： Although the shelf life of pasteurized products is shorter than that of high-temperature sterilized products, it significantly extends the safe consumption period, particularly suitable for refrigerated foods.
- High Automation： Modern pasteurization lines are equipped with advanced equipment such as automatic temperature control systems, variable frequency drives, and computer controls, enabling high automation, increasing production efficiency, and reducing labor intensity.
- Safe and Sanitary： Pasteurization equipment is typically made of food-grade stainless steel, easy to clean and sanitize, complying with food safety and hygiene standards, thereby ensuring product safety.
Considerations
- Disinfection Time and Temperature： The effectiveness of sterilization depends on heating time and temperature. Appropriate settings should be determined based on the food type and desired sterilization level.
- Removing Surface Contaminants： Before sterilization, food surfaces should be cleaned to remove dirt and residues to ensure sterilization efficacy.
- Safe Operation： During sterilization, avoid contact with hot liquids and steam to prevent burns. Personal protective equipment should be worn to avoid liquid splashes into the eyes, mouth, or skin.
- Proper Storage： Pasteurized foods should be stored at appropriate temperatures to maintain safety and quality. Generally, pasteurized foods should be kept at around 4°C and consumed within 3-10 days.
Conclusion
Pasteurization, as an important food processing technology, uses its unique advantages to ensure food safety. While maintaining food nutrition and flavor, it effectively eliminates pathogenic microorganisms in food and provides consumers with safe and healthy food. As technology advances and consumers’ requirements for food safety increase, this technology will continue to expand its application and development.
