Fish Microbiology and Quality Assurance

Unit 4 - Food preservation techniques and microorganisms

4.2.2. Sterilization
Sterilization or appertization refers to destruction of all viable organisms in food as measured by an appropriate enumeration method. This process kills all viable pathogenic and spoilage organisms. However, organisms that survive are non-pathogenic and unable to develop in product under normal conditions of storage. Thus, sterilized products have long shelf life.
Commercially sterile or commercial sterility is often used for canned foods to indicate the absence of viable microorganisms detectable by culture methods or the number of survivors is so low that they are of no significance under condition of canning and storage.
Processing of food for preservation using high temperature depends on the physical nature of the food. Foods (solid or semisolid) are generally processed by packing in cans, sealing and then sterilized. Most liquid foods are sterilized, packed in suitable containers and sealed aseptically. Temperature and time of sterilization given to a food depends on the nature (pH, physical state, nutritional type etc) of the food being processed.