Environmental Engineering Reference
In-Depth Information
from the point of preparation to the point of consumption to prevent foodborne
illnesses.
The approximate optimal temperature for growth of the principal organisms
associated with foodborne illnesses are salmonella 99
◦
F(37
◦
C) (maximal 114
◦
F),
Staphyhcoccus aureus
99
◦
F (maximal 114
◦
F),
Clostridium perfringens
115
◦
F
(46
◦
C) (maximal 112
◦
F), and enterococci (maximal 126
◦
F).
Listeria
, in contrast,
can grow at lower temperatures and is thus often associated with contaminated
of refrigerated deli meats and soft cheeses.
63
Salmonellae are widely distributed in nature and found in many raw food prod-
ucts, especially poultry, beef, and swine. Pets are also reservoirs of salmonellae,
and outbreaks of
Salmonella
have also been associated with pet food.
64
Tables
and surfaces used in preparing raw poultry and other meats can serve as vehicles
for the spread of
Salmonella
and other pathogens unless they are thoroughly
cleaned and sanitized between each use.
Clostridium perfringens, Campylobac-
ter jejuni
,and
Staphylococcus aureus
are also frequently found in samples of
raw beef and on workers' hands, knives, and cutting boards, as well as in soil,
dust, and the intestinal tracts of humans and other warm-blooded animals. Raw
meat and seafood should be separated from other food in the grocery cart or
refrigerator; persons should always wash hands, cutting boards, and dishes with
hot soapy water after coming in contact with raw meat, poultry, or seafood; one
cutting board should be used for raw meat, poultry, and seafood and another for
foods that are ready to eat; cooked food should never be place on a plate that
previously held raw meat, poultry, or seafood.
63
Salmonellae may survive up to 10 months in cheddar cheese. Aging of
salmonella-infected cheese 60 days, manufactured from heat-treated (nonpas-
teurized) milk, is therefore ineffective to prevent human illness. The use of
pasteurized milk can ensure the marketing of safe milk and milk products,
including elimination of
Salmonella
spp.,
Listeria, Yersinia, Campylobacter
,
enterohemorrhagic
E. coli
, and other pathogens.
65
Thorough cooking 165
◦
F
(74
◦
C) of raw shell eggs, raw meat and poultry, raw clams, and other foods
of animal origin before consumption will prevent salmonellae infections, as
will the use of pasteurized egg products in preparing eggnog, Caesar salad,
hollandaise sauce, and homemade mayonnaise and ice cream. Eggs should not
be used raw and should be cooked thoroughly before service. Flocks and eggs
have been found infected.
66
Cross-contamination during food preparation should
be avoided.
Fish that has been fried, baked, or broiled until it flakes when pried with a fork
can be assumed to be free of viable parasites. Freezing fish at
−
4
◦
F(
−
20
◦
C) for
three to five days will also kill most pathogens. Cooking fish to a temperature of
145
◦
F(63
◦
C) will kill parasites.
63
Campylobacter jejuni
is responsible for numerous foodborne outbreaks, many
of which are not recognized.
Campylobacter
contamination of food products
may begin during animal slaughtering and processing and may be increased
by overconcentration of animals in feedlots and brooding houses. Poor food
handling, storage, and sanitation facilitate
Campylobacter
transmission.
