Louis Pasteur
As we all know pasteurization is named after Louis Pasteur who discovered that spoilage
organisms (like lactic acid bacteria: leuconostoc, pediococcus, and lactobacillus) could be
inactivated in wine by applying heat temperature.
Mild Heat Treatment
Pasteurization is a mild heat treatment of liquid foods (both packaged and unpackaged) where
it is a designed to kill the most-heat resistant vegetative pathogens (like salmonella, listeria,
campylobacter, staphylococcus aureus, and e, coli) but not harm the flavor or the quality of
the food.
Not a form of Sterilization
Note that this is not a form of sterilization. Sterilization completely eliminate all living
microorganisms. While pasteurization is a mild heat treatment below its boiling point <100 C
or <212 F intended to only destroy or deactivate organisms and enzymes but not the bacterial
spores (like bacillus & clostridium) which is thermoduric. However, a double pasteurization will
extend the quality by killing spores that have germinated in an already packaged product.
Extend shelf life for months
The purpose of pasteurization is to extend shelf life for months. This will be further discussed
on the next slides.
In low acid foods like milk and liquid eggs, pasteurization minimize hazards in pathogenic
microorganisms which extend shelf life for days.
In acidic foods like bottled fruit and beer, pasteurization is responsible to the destruction of
pathogenic microorganism, enzyme inactivation (like pectin methylesterase and
polygalacturonase in fruit juice)
*Not all spoilage organisms are destroyed under pasteurization parameters, that is why
refrigeration is necessary.
Liquid eggs - blended egg whites & egg yolk without the cracking open ordeal
Listeria – ready to eat foods ( meat poultry, seafood, and dairy-unpasteurized milk)
Campylobacter – undercooked poultry, unpasteurized milk, and digestive systems of animals
E. coli – raw milk, undercooked ground meat, intestine
Thermoduric – able to survive high temperatures
Clostridium – low acid preserved vegetables, canned tuna, fermented salted, smoked products