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FOOD 2010 Chapter Notes -Hazard Analysis And Critical Control Points, Gastroenteritis, Pressure Cooking


Department
Food Science
Course Code
FOOD 2010
Professor
Massimo Marcone

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UNIT 06: FOOD SAFETY
CHAPTER 11 (Pgs 303-326)
Foodborne illness: any illness resulting from ingestion of food
If agent causing disease is detected in sample of food victim has eaten
If there is cluster of cases among people who have nothing in common except food they ate
If intestinal tract is affect
If symptoms are like foodborne illnesses
Biological hazards: bacteria, molds, viruses, parasites (protozoa, flatworms, roundworms)
Chemical hazards: chemical substances that occur naturally in foods (pplant toxins) and those added to food
(antibiotics)
Physical hazards: bone, metal, plastic, other foreign matter that can damage consumer if ingested
Bacterial Causes
Foodborne infection
Invade intestinal tract
During colonization, epithelial cells lining intestine are damaged, disrupting uptake of solutes into body of
cells
Results in imbalance in osmotic pressure, causing water to be secreted from tissues back into intestinal
tract
Excess of water responsible for loosening of stool (diarrhea)
Damage of intestinal lining sends message to brain that triggers vomiting response
12 hours 2 days
Examples: Salmonella, Yersinia, Shigella
Foodborne intoxication
Produce toxin in food during growth
Foods contaiminated with toxin-producing or ganims (Staphylococcus aureus or Clostridium botulinum)
Onset of disease is very fast
Examples: E. coli
Foodborne intoxification
Caused by ingestion of bacteria that once inside small intestine, produces toxin
Toxins absorbed by body, reaching kidneys where they cause substantial damage to convoluted tubules
Mycotoxins from molds
Compounds have no apparent usefulness to mold use up amino acids, acetate, pyruvate to prevent
over accumulation of compounds
Range in toxicity (vomiting, to gangrene, bone marrow destruction, renal disorders, liver cancer)
Virus Transmission
Incubation period for foodborne viral illness is usually several weeks time viral particles invade host
cells to replicate
Transmission can be through fecal-oral route
Ex. food handler suffering from hepatits A doesn’t wash hand after restroom hands contaminated with
fecal material that contains viral particles touching foods that are to be eaten transfers virus to
unsuspecting consumer
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Ingestion of parasites
Protozoa
Typically harbored in intestinal tract of animals
When parasite is shed in feces of animal, it is in form of a cyst cysts can contaminate surface of meat,
thus be ingested through consumption of undercooked meat
Once inside body, cysts germinate growing cells that persist inside body for life
Onset of disease is typically at least one week
Giardia lamblia giardia occurs in form of pear-shape cyst, which germinates upon ingestion
One cyst yields 2 trophozoites have 8 flagella that help propel them by falling-leaf type of motility
Trophozoites penetrate intestinal wall but not deep cramps, nausea, weight loss, severe diarrhea,
vomiting, flatulence
Onset is 1-2 weeks and up to 3 months
Highly contagious, with contaminated water and meat being prime sources of infection
Toxoplasma gondii harbored in house cats
Oocysts in fecal material are ingested pass to intestine where they release 8 sporozoites Pass
through intestinal wall into circulatory system
Able to multiple fast in many parts of body
Referred to as tachyzoites and forms clusters surrounded by protective wall
Then called bradyzoites don’t grow but persist in body for life
o When immunity suppressed, bradyzoites break and release tachyzoites, which multiply rapidly
bringing another acute infection easily transmitted through placenta
Cysts destroyed by heating and freezing
Cryptosporidium and cyclospora exist as oocyts are found in untreated water
Oocysts resistant to chlorine have implicated in outbreaks related to swimming activities
Once ingested, oocysts give rise to 4 sporozoites in intestinal or respiratory tract
o Sporozoites attach to surfaces, developing feeder organelle that helps parasite ingest nutrients
from host
o Sporozoite transforms into trophozoite and then to schizont
o Schizont releases several merozoites penetrate other epithelial cells of intestine
o Merozoites undergo cell division and give rise to 8 oocysts (some thin wall and some have thick
wall)
o Thin-wall oocysts give rise to autoinfection since they penetrate the intestinal wall
o Thick walled oocysts shed in feces of sputum and infect other people who ingest material
contaminated with feces
Symptoms develop within 2-14 days with water diarrhea, anorexia, weight loss, dehydration, abdominal
discomfort lasting 3 weeks
Flatworm
Exists in form of eggs in soil
Cattle ingest eggs and once inside, eggs release embryo, which penetrate intestinal tract of animal
Embryos will travel to other tissues, such as muscle and develop into larvae
Consumption of meat from these animals will result in ingestion of larvae by humans, causing disease
Taenia saginata (beef) and taenia solium (pork) intermediate hosts for parasites with humans being definitive
hosts
Worms do not have vascular, respiratory, or digestive systems use host to obtain nourishment
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