Modules
C. Food Safety
1: Potentially Hazardous Foods
Objective: to define potentially hazardous food under the California Health and Safety Code.
"Potentially hazardous food" under most cases must be stored below 41 degrees F. or above 140 degrees F. These foods have the highest potential for spreading foodborne illness. Its fundamental legal definition is:
food that can support rapid and progressive growth of microorganisms
that may cause food infections or food intoxications.
A legal exception to this definition is Clostridium botulinum. Because of the extreme toxicity of its toxins, rapid and progressive growth is not necessary for botulism. Any growth or toxin production of this organism represents a significant risk.
Because of the significance of potentially hazardous food, the following conditions (defined by law) allow us to determine foods that are not potentially hazardous:
-- pH of 4.6 or less,
-- Aw (water activity) of 0.85 or less,
-- canned (in hermetically sealed and commercially sterilized containers), or
-- exempted by appropriate microbial challenge studies.
Try the links to the California Health and Safety Code (click first on "food sanitation" given just below, and then select "CURFFL"), and look at the additional distinctions provided under the law. It is one of the most important definitions you will ever work with in the field.
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2. Selected Food-borne Illnesses
A. Infections
1. Salmonellosis Salmonella typhimurium
Salmonella enteritidis
Salmonella is one of the best known and most common of foodborne infections. With an incubation period of about 12 to 36 hours, it produces gastroenterities (vomiting and diarrhea) that is common to so many of these foodborne illnesses. Salmonella enteritidis is associated with raw eggs, even when they are uncracked and undamaged.
2. Campylobacter Campylobacter jejuni
Campylobacter is probably one of the most common foodborne infections that you never heard of! One of the most common of infections, it has an incubation period of about 5 days.
3. Listeriosis Listeria monocytogenes
This is the infection associated with Jalisco foods some years ago that killed over 50 people in Los Angeles.
4. Hepatitis type A = infectious
This is the so-called "infectious hepatitis" (though of course many of them are infectious) that is most closely associated with eating raw oysters.
5. Brucellosis Undulant Fever
This is an important illness because it is associated with improper pasturization.
6. Trichuriasis Trichuris thrichiura
7. Anisakiasis
This is associated with raw fish, particularly sushi and sashimi, but also herring and seviche in other parts of the world. It gets its name from the Anasakidae family, a family of parasitic worm that normally reside in fish. They would be easily killed bycooking, but its the raw serving of fish that causes this problem.
B. Intoxications (primarily exotoxins)
8. Staphyloccoccus Staphyloccoccus aureus
This is one of the most common of foodborne intoxications. A large percentage of healthy humans carry Staphylococcus. If introduced into food and allowed to sit at room temperature, they produce toxins that can cause a nasty gastroenteritis. With a distinctive incubation period of about 2-4 hours, the illness is intense but normally doesn't last long.
9. Botulism Clostridium botulinum
The good news is that this illness is fairly rare in this country these days. The bad news, as almost everyone knows, is that botulism can kill you if you don't receive the antitoxin in time. The early symptoms include dizziness and double vision.
10. Perfringens Clostridium perfringens
This is another agent in the Clostridium family. The good news is that it is not nearly as deadly as botulism. The bad news is that it is far more prevalent.
C. Poisonous plants/animals
11. Favism Vicia faba
12. Snake root Eupatorium
Snake root is basically a weed. If cows eat these weeds, you can get sick from drinking the cow's milk.
13. Paralytic shellfish poisoning
14. Ciguatera
15. Scombroid
Scombroid is a poisoning from histamines in certain fish. Especially common to California and Hawaii, it gets its name from the Scombridae family, which include tuna. The treatment, as you might guess, is an antihistamine.
D. Others
16. agent: Vibrio parahemolyticus
reservoir: oceans (variety of seafood)
transmission: poorly cooked seafood
symptoms: diarrhea, abdominal cramps (rarely fatal)
17. agent: Bacillus cereus
reservoir: soil
transmission: especially cooked rice at room temperatures
symptoms: sometimes vomiting, sometimes diarrhea
18. agent: Clostridium perfringens (anaerobic sporeformer)
reservoir: soil; also, GI tract of healthy humans or animals
transmission: spores survive normal cooking,
then germinate, multiply, and produce toxins
symptoms: diarrhea, nausea; usually no vomiting or fever
19. agent: Copper poisoning
transmission: copper in prolonged contact with acid foods or
carbonated beverages
(e.g., improper vending machines)
symptoms: vomiting and weakness in < 1 hour (often minutes)
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A. Pasteurization:
Pasterization is NOT sterilization (i.e., kills all microbes). It's not even disinfection (i.e., kills all pathogens). It's designed to be a measure that protects public health without completely destroying the taste of foods. Sterilization is normally achieved at 240 degrees Fahrenheit or higher, whereas pasteurization occurs at much lower temperatures. The different types of pasteurization, with temperatures and the time it needs to stay at that temperature, are shown below.
1. Ultra Pasteurization: >280 deg. F for >2 seconds
2. Ultra High Temperature: 191-212 deg. F. for 1 to .01 seconds
(UHT)
3. High Temp. Short Time: 161 deg. F for 15 seconds
(HTST)
4. Holder pasteurizer: 145 deg. F for 30 minutes
B. Food and Temperatures:
5. Thermometers: required in refrigerators.
should be: readily visible
at the warmest part of the unit
accurate to 1 degree Centigrade
6. Stem designed to check food temperatures
(or probe) typically has metal stem
thermometer: with temperature readings at top of thermometer
Restaurant operators must have on the premises.
7. Maximum used to check temperatures in dishwashing machines
registering
thermometer:
8. Refreezing: frozen foods may not be thawed and refrozen
(exception: when food is cooked or processed
after thawing).
C. Canning operations:
1. soaking reduces spoilage bacteria
and washing:
2. sorting consistent quality of product
and grading:
3. blanching: direct contact with hot water or steam
destroys enzymes (reducing chemical changes)
softens tissues to fit in can
washes away "raw" flavor
4. exhausting: heat foods in cans prior to closing can
produces partial vacuum
Exhausting is not the "sterilization" step in canning.
The time they are held at these temperatures is not enough
for sterilization.
5. sealing: secures lid on can
hermetic double seam
when can cools, lids pull in (concave)
6. retort closed vessel for "sterilization" of food
processing: 240 degrees for 30 minutes
7. cooling: quick cooling minimizes thermophilic bacteria
potential for water contamination through seams
(water must be disinfected)
Thermophilic spoilage agents refer to bacteria that are not necessarily pathogens (i.e., they do not cause illness), but can certainly ruin foods and are able to survive warm temperatures. They are normally tougher to kill than pathogens and are therefore a big concern in the canning process. If canning is improper, we will in all likelihood see these spoilage agents first. They go by such names as flat sour spoilage(the cans stay flat but the taste is sour), TA spoilage (thermophilic anaerobes that casue the cans to swell due to gas production), and sulfide spoilage (due to the truly awful sulfide smell associate with these agents).
D. Dishwashing:
8. Manual 3 compartment sink:
method:
detergent and warm water:
good at removing, not killing bacteria
most important step in dishwasing
rinse: removes detergent before sanitizer
sanitizer:
a "polishing" step
hot water (180 deg F, 30 seconds)
chemicals and warm water (75 deg F):
chlorine: 100 ppm for 30 seconds
quaternary ammonia: 200 ppm for 1 minute
iodine: 25 ppm for 1 minute
9. Machine see NSF standards
method: (National Sanitation Foundation)
wash: 140-160 deg. F
rinse: 180 deg F, 10 seconds, 15-25 psi (water pressure)
or chlorine rinse (50 ppm)
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4. HACCP = Hazard Analysis and Critical Control Point
developed by Pillsbury Company for NASA astronauts in 1960s
since then, adopted by FDA, USDA, and Dept. of Commerce
predicts hazards and controls them before they happen
1. Identify hazards
(i.e., biological, chemical, and physical hazards)
identify potentially hazardous foods
assess risk (e.g., high, medium, low, negligible)
2. Identify critical control points
def. = any point in an operation where the hazard can be
eliminated, prevented, or minimized
observe the handling of food throughout its lifetime
identify: sources of contamination, and
potential for microbes to survive or grow
3. Establish controls
identify: control criteria (e.g., temperatures)
corrective action
4. Monitor
monitor the critical control points
record the data
5. Establish corrective action
take action when criteria are not met
6. Verify that HACCP is functioning
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5. Food Safety: Who does what in the federal government?
A. hopelessly 35 laws
fragmented:
12 agencies
51 interagency agreements
(not counting federal-state
interagency agreements)
B. 6 major 1. Food and Drug Administration (FDA)
agencies:
2. Environmental Protection Agency (EPA)
3. National Marine Fisheries Service (NMFS)
U.S. Department of Agriculture (USDA):
4. Food Safety and Inspection Service (FSIS)
5. Agricultural Marketing Service (AMS)
6. Federal Grain Inspection Service (FGIS)
C. funds: USDA receives about 3/4 of federal funds
FDA is second, with about 1/8 of federal funds
D. FDA 1. Food Drug and Cosmetic Act
major
laws: 2. Egg Products Inspection Act
3. Federal Anti-tampering Act
4. Import Milk Act
5. Infant Formula Act
6. Pesticides Monitoring Improvements Act
7. Public Health Service Act
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1. DES: Diethylstilbestrol
synthetic estrogen
used to fatten cattle and chickens
effects: carcinogen, mutagen
FDA banned in 1977
2. sodium illegal to mask food
nitrite: interferes with browning of meat:
myoglobin + sodium nitrite --> met-myoglobin
deters spoilage and botulism in cured meats
effects: headaches or hives in sensitive persons
nitrites --> nitrosamines (carcinogen)
however: not a direct additive
no evidence of increased cancer
nitrates reduce to nitrites inadult saliva
(nitrates found in spinach, celery,
lettuce, etc.)
3. monosodium (MSG, flavor enhancer, natural flavoring,
glutamate: hydrolyzed vegetable protein)
effects: headaches, nausea, diarrhea,
burning sensation, chest pain, etc.
brain lesions in monkeys and mice
4. aspartame: only in sensitive persons (phenylketonurics)
effects: swelling of eyelids, lips, hands, or feet
5. sulfites: effects: abdominal cramps, diarrhea,
low blood pressure, elevated pulse,
light headedness, chest tightness,
asthma, hives
FDA banned use on raw fruits and vegetables
FDA requires labels when more than 10 ppm
Test your knowledge with a: quiz
For more information, try: food sanitation