Pasteurization from lsn 8 in your SEPUP textbook!

I N V E S T I G AT I N G F O O D S A F E T Y : A C T I V I T Y 8
© 2003 REGENTS OF THE UNIVERSITY OF CALIFORNIA

Pasteurization

In the 1860s, French scientist Louis Pasteur discovered that heating
wine and beer to about 135°F (57°C) for a few minutes would prevent
the growth of microorganisms. Today, the process of heating foods to
high temperatures for a period of time is known as pasteurization.
After food has been pasteurized, it is kept in air-tight containers and
often refrigerated. This process helps keep disease-causing microorganisms,
such as E. coli and Salmonella, from growing in the food and
making people sick. It is one method of insuring the safety of milk
and juices sold in stores. In the United States, 98% of all fruit and vegetable
juices are pasteurized.

Pasteurization can reduce the nutritional value of food. Orange juice,
for example, may lose up to 30% of its vitamin C during pasteurization.
But even after pasteurization, a glass of orange juice still provides
120% of the recommended daily allowance of vitamin C.

Some people feel that pasteurization affects the flavor of fresh
juices such as apple cider. Until 1996, unpasteurized apple juice
was thought to be safe from the possibility of E. coli contamination
because of its acidity. In that year, however, approximately
65 people became sick from E. coli bacteria after drinking
unpasteurized juice. One 16-month old baby died. Research
from the U.S. Centers for Disease Control later revealed that
bacteria can survive at a pH as low as 4.0; the contaminated
juice had a pH of 4.3. The U.S. Food and Drug Administration
now requires juices that have not been pasteurized to carry a
warning label informing customers that the product “may contain
harmful bacteria that can cause serious illness in children,
the elderly and persons with weakened immune systems.”
Today, most large food processing companies use some method
of pasteurization on their products. But not every company can
or wants to pasteurize its products.Many small companies have
had a difficult time paying the cost of the pasteurization equipment;
other small businesses believe their customers prefer the
taste of unpasteurized juices.