Lecture Week 8
Food-borne Hazards and Human Health
Escherichia coli (from drinking water)
Botuslim (an illness from bacteria)
o Shellfish-associated toxins
o Color additives
o Bioengineered foods
Types of food that are prone to contamination
o N.America has one of the food supplies in the world; however, there is a still a
significant amount of food-borne illness.
o Meat, milk, dairy products, unpasteurized fruit and vegetables juices, raw or
undercooked eggs, chicken, tuna, potato and macaroni salads, cream filled pastries,
fresh produce, spices, chocolate, seafood
o Careless handling can lead to diseases.
Food cannot stay in room temperature for a long time
Hot food and cold food should not be kept in room temperature for a long time
and is a perfect environment for bacteria growth
Improper cooking of raw meat contaminated during process can lead to food-
Cutting boards and kitchen tools. If you cut meat with a cutting tool, do not re-
use that tool on cutting vegetables unless proper cleaning of the tool has been
Symptoms of Food-borne illnesses
o Diarrhea, abdominal cramping, fever, vomiting, headache, sometimes blood in the stool.
o Usually lasts only a day or two sometimes 7-10 days
o These symptoms for most people are not life threatening and don’t require any medical
help most often
o Sever e cases may occur in children, older people and those with serious conditions.
Prevention of Food-borne illnesses
o The prevention begins in the supermarket
When buying food, always check the labels for expiration dates, don’t buy open
packages of meat, don’t buy vegetables from the trunk of a car, don’t buy sushi
from a homeless man
Store the product in a safe place (to keep them away from robbers). If the food
belongs in the freezer, it must be kept in the freezer.
Food should be prepared in a clean kitchen. Do not clutter the kitchen counter,
sink, table and etc. Clean the sink using a commercial cleaning products or something
natural like chlorine bleach (e.g. 1 tspn of bleach in 1 L of water).
Hot food should be kept hot and cold food should be kept food
Cook the food, don’t eat raw foods you cannibal
Store the leftovers in fridge but no longer than 3-4 days. Food should not be left
on the table (open environment) for longer than 2 hours.
Wash your hands before handling your foods and after you are done (especially
when you are working with meat).
o Bacteria: E.coli
Food poisoning usually associated with eating unwashed vegetables and meat
Grounded beef: very easy to contaminate, often contaminated during the slicing
and processing of meat.
Diarrhea, abdominal cramps
Complications: hemolytic uremic syndrome in which the red blood cells are
destroyed and kidneys fail (2-7% cases). Recovery stages take a long time.
o Bacteria: Salmonella
Very common in daycares; easily transmitted between kids in daycares
Common disease that transfers from animals to humans; especially reptiles
(small turtles). A report of children touching turtles get sick. Why? The tiny
particles of feces are found all over the turtles skin and are exposed to the
human hand and can enter through the mouth and nose if hands are not
Some vegetables can be a source of this disease (e.g. spinach).
Not very serious and does not require treatment
o Bacteria: Botulism
Dangerous but very rare and fatal.
The bacteria that causes botulism is clostridium botulinum which produces a
nerve toxin leading to the illness
Major source of contamination is homemade canned foods
Commercial canned foods undergo botlinum cook which destroys the toxins
using high temperatures (150 F).
Normally found in the soil in the dormant state
Unusual sources: Garlic or herbs stored covered in oil; improperly handled
baked potatoes wrapped in aluminum foil; home-canned or fermented fish
There are three types of botulism:
All symptoms are neurological and occur between 12-36
hours after consuming the botulinum toxin
Double and/or blurred vision
Difficulty swallowing, severe constipation
Muscle weakness, lead to body paralysis
Wound botulism: open wounds contaminated with bacteria
Infant botulism: consuming the spores of clostridium botulinum; usually
by kids o Parasites and Foodborne Illnesses
Very small and can or cannot be seen by the naked eye
Live and reproduce within the tissues and organs of the infected human and
May be transmitted from animal to humans, from humans to humans, or from
humans to animals
Some are very small; some are visible with the naked eye (e.g. w