The document briefs about the technique pasteurization. It is an important food preservation method. This is used in the food technology industry. The document details the major aspects of the technique.

1. FOOD PRESERVATION
BY: POORVAJA GANESAN

2. Pasteurization:
DEFINITION:
Pasteurization is a process that kills microbes (mainly bacteria) in
food and drink, such as milk, juice, canned food, and others. It was
invented by French scientist Louis Pasteur during the nineteenth
century.
Introduction:
 Pasteurization is not the same as sterilization. Its purpose is to
reduce the bacterial population of a liquid such as milk and to
destroy organisms that may cause spoilage and human disease.
Spores are not affected by pasteurization. The intent
of pasteurization of milk is to eliminate pathogenic microbes.
 Two types of pasteurization are in use today. In the high-
temperature, short-time treatment process, milk is run between
metal plates and heated pipes for 15 seconds.
 Pasteurized milk, contrary to some claims, does not cause
lactose intolerance or milk allergies and does not lessen
nutritional value. It also does not last when stored outside of the
refrigerator.
 Pasteurization is important because it kills harmful
bacteria. Raw milk and dairy products can contain
microorganisms such as Salmonella, E. coli and Listeria that
cause food-borne illnesses.

3. Here are some common pasteurized foods that may seem "healthy,"
but are actually missing key enzymes and nutrients to keep you at
your healthy best:
 Milk.
 Butter.
 Cheeses.
 Cream.
 Vinegar.
 Almonds.
 Commercial sauerkraut.
 Yogurt.
PRINCIPLE:
The process of heating milk to such temperature and for such periods
of time as required destroying the pathogens which may be present,
whilst causing minimum changes in the composition, flavor and
nutritive value. The two primary aims of the process is to remove
pathogenic bacteria from food, thereby preventing diseases and to
remove spoilage (souring) bacteria to improve its shelf life.
PROCESS:
The pasteurization process occurs when milk is heated to just below
boiling temperatures.

4. 1. Flash Pasteurization - Involves a high-temperature, short-
time treatment in which pourable products, such as juices, are
heated for 3 to 15 seconds to a temperature that destroys
harmful micro-organisms. After heating, the product is
cooled and packaged. Most drink boxes and pouches use this
pasteurization method as it allows extended unrefrigerated
storage while providing a safe product.
2. Steam Pasteurization - This technology uses heat to control
or reduce harmful microorganisms in beef. This system
passes freshly-slaughtered beef carcasses that are already
inspected, washed, and trimmed, through a chamber that
exposes the beef to pressurized steam for approximately 6 to
8 seconds. The steam raises the surface temperature of the
carcasses to 190° to 200° F (88° to 93°C). The carcasses are
then cooled with a cold-water spray. This process has proven
to be successful in reducing pathogenic bacteria, such as E.
coli O157:H7, Salmonella, and Listeria, without the use of

5. any chemicals. Steam pasteurization is used on nearly 50% of
U.S. beef.
3. Irradiation Pasteurization - Foods, such as poultry, red
meat, spices, and fruits and vegetables, are subjected to small
amounts of gamma rays. This process effectively controls
vegetative bacteria and parasitic food borne pathogens and
increases the storage time of foods.