Food processing is used to achieve preservation and reduce the risk of spoilage. It increases shelf-life, stabilizes food texturally and ensures that products meet high-quality standards. Traditional food processing methods such as sterilization, pasteurization, blanching and microwaving destroy human pathogens and microorganisms which cause foods to spoil. These traditional methods are widely used for various foods and beverages throughout North America.
Pasteurization is a process named after the inventor and scientist Louis Pasteur. This traditional food processing method destroys human pathogens in food and is primarily used in the dairy industry for milk preparation and starter cultures for cheese, yogurt, buttermilk and ice cream.
Today, the United States uses the high temperature-short temperature pasteurization method, which raises the temperature of milk to 161 degrees F for 15 seconds followed by quick cooling, according to the USDA. Pasteurization makes milk products safe for human consumption, while also improving and retaining the quality.
Sterilization is a traditional food processing method that inactivates enzymes with heat while minimizing the formation of residue. It is used to destroy all human pathogens and microorganisms, which promote deterioration in foods. All canned foods are sterilized in large pressure cookers to ensure preservation for two or more years, according to the Ontario Ministry of Agriculture.
Sterilization may not kill all organisms therefore, as with any food product, appropriate precautions must be taken, such as refrigeration, proper handling and cooking to ensure food organisms are handled correctly and will not create any health risks.
Blanching is a thermal treatment, which processes food with hot water or steam. This traditional processing method is used primarily for canned or frozen vegetables. It deactivates enzymes that deteriorate the color, texture, flavour and nutritional value in the vegetables.
Vegetables are blanched prior to canning to help clean and reduce microorganisms and entrapped gases. Blanching also prevents the vegetable’s leafy tissues from wilting, which allows for easier handling during the packaging process.
Microwaving is a traditional food processing method that uses heat for small quantities of food such as frozen entrees. Microwave ovens use electromagnetic radiation to stimulate the water molecules found in food, which then spreads by conduction to the center of the food.
Microwaves infiltrate the food 10 inches from the source of radiation and actually penetrate three to four inches into the food. Therefore, ovens may be limited in size to cook portions quickly. The effectiveness of microwaving is lost on larger quantities of food.