thermal processing

Thermal processing is a method of food preservation that uses a combination of temperature and time to eliminate microorganisms. This process is crucial for making food safe to eat and extending its shelf life.

Different thermal processing techniques exist, each with specific applications:

• Pasteurization: This involves heating food to a moderate temperature to destroy harmful pathogens and inactivate spoilage enzymes. It minimally affects the food's sensory and nutritional qualities. Examples include pasteurizing milk at 72°C (162°F) for 15 seconds or fruit juices at 77°C (171°F) for 1 minute.1
• Blanching: Primarily used for vegetables before freezing, drying, or canning, blanching involves heating to near 100°C (212°F) for a few minutes. It cleans the product, reduces microbes, removes gases, and wilts tissues.2
• Canning: This method involves sealing food in airtight containers and heating them to eliminate microorganisms. Developed by Nicolas Appert, it uses tin cans or glass jars and is designed to achieve commercial sterility, meaning very few non-sterile packages.34
• Aseptic Processing: This advanced technique sterilizes both the food and its packaging separately before combining them under sterile conditions. It often uses high-temperature, short-time (HTST) methods to preserve food quality better than traditional canning.4

While thermal processing is effective, some heat-sensitive nutrients, like vitamin B1 and vitamin C, can be lost during the process.3