complete destruction of microorganisms through extended heat treatment or use of
entire portion of food is exposed to wet heat to reach a temp of 121 degrees C for 15
in commercially- sterile foods (e.g.: canned and bottled foods), all pathogenic and toxin
producing organisms, as well as spoilage microorganisms, are destroyed. Some heat-
resistance bacterial spore may remain, however are unlikely to multiply.
commercially-sterile foods have a shelf-life of 2 years or more.
heating foods to a specific high temperature (approx. 80-90 degrees) for a short time kills most
pathogenic microorganisms, and to extend the shelf life of the food. The amount of time
required depends on the temperature used. See table 16.2: pasteurization temperature vs time
differs from sterilization b/c lower temperature is used
pasteurized food is not sterile, so it must be refrigerated or preserved by other means.
Ex: pasteurized milk or eggs are found in the refrigerator section of the grocery store and must
be stored in our fridge at home
pasteurization of milk and fruit juices can result in loss of vitamin C. However, there are no
adverse nutritional implications. Milk is low in vitamin C, while the amount remaining in
pasteurized orange juice will provide the recommended daily intake
Flash pasteurization uses higher temperatures, for a short period of time (3-15 seconds) to
destroy pathogenic microorganisms. Also called “high-temperature, short time” (HTST)
pasteurization or “ultra-high temperature” (UHT) pasteurization. The product is quickly cooled
after the heat treatment and then packaged. This allows the product to be safely stored
unrefrigerated for extended periods of time (e.g. drink boxes and pouches). For ex: you can find
milk in your grocery store sold in tetra packs that is not refrigerated. This is b/c it has undergone
flash pasteurization, so does not require refrigeration until after the product is opened.
a quick heat treatment applied to vegetables and fruit to inactivate natural food enzymes that affect
colour and texture and to decrease oxidative degradation of the food.
the food is briefly dipped into boiling water or briefly exposed to steam
commonly done before freezing fruits and vegetables, b/c freezing does not completely stop
enzyme activity e.g. potatoes are blanched before being frozen as french fries to maintain their
texture. green beans are blanched before they are frozen to help maintain their bright green
food is held at a temperature above 110 degrees C for a number of minutes
kills most harmful or spoilage-causing microbes and their spores, however canned f