Unformatted text preview: Nutrition: Concepts and Nutrition: Concepts and Controversies, 8 ed
Food Safety and Food Technology FDA: Food & Drug Administration
FDA: Food & Drug Administration The major agency charged with monitoring the food supply in the U.S.
Is the agency that decides what additives may be used in foods, based on safety and effectiveness
Has identified a list of 5 areas of concern, in order of priority FDA Prioritized Concerns
FDA Prioritized Concerns
Microbial foodborne illness
Natural toxins in foods
Residues in foods 1.
2. Environmental contaminants other than pesticides
Animal drugs Nutrients in foods
Intentional food additives Foodborne Illness
Foodborne Illness Episodes of food poisoning far outnumber any other kind of food contamination
In U.S., estimated 81 million people become ill & about 9,000 die each year from foodborne illness
Can be caused by actual infection with bacteria (as with salmonella & E. coli) or by toxin produced by bacteria (as with botulism and staph)
Majority of cases result from errors made in food handling AFTER purchase, but incidents which result from prepurchase contamination affect larger numbers of people at once & get much more media attention Botulism
Botulism Caused by the toxin of Clostridium botulinum (anaerobic) which grows in improperly canned (esp. homecanned) foods
Improperly prepared or stored vacuumpacked foods
Oils flavored with herbs, garlic, vegetables, etc. which are stored at room temperature Grows in low acid conditions
Often fatal, & leaves prolonged symptoms
See p. 509 & 511 for warning signs, onset time, how to avoid Toxin can be destroyed by heat (boiling for 10 minutes) Food Safety:
When making flavored
oils, wash and dry the
herbs before adding
them to the oil, and
keep the oil
refrigerated. Top Four Causes Top Four Causes of Foodborne Illness Campylobacter: Undercooked poultry, unpasteurized milk
Salmonella: uncooked or undercooked eggs, unpasteurized milk, raw meat & poultry, vegetables & fruits
E. coli: Raw or undercooked beef, unpasteurized milk, raw vegetables & fruits, contaminated water
Norwalklike viruses: Undercooked seafood (contaminated by human feces from boat bilge) Incidence of Top Two
Incidence of Top Two Campylobacter: greatest number est. 2,453,926 cases/year in U.S. (Almost double that of estimated Salmonella cases. Found on up to 80% of chickens, 20% representing a strain resistant to antibiotics. Onset 25 days after eating.
Salmonella: estimated 1% of U.S. population experiences infection yearly. Food Safety
Thermometers. Meats & Poultry
Meats & Poultry Especially prone to bacterial growth due to high protein & moisture content, as well as probable contamination with bacteria Should thaw meats in refrigerator
Must avoid crosscontamination of other foods Never place where juices can drip on other foods
Wash hands and thoroughly clean surfaces used for preparation of meats
Never place cooked meat back on plate used for raw meat Must cook to proper temperature to kill microbes Meats, Poultry (cont.) & Eggs
Meats, Poultry (cont.) & Eggs Best NOT to cook large, thick, dense foods such as roast or meatloaf in the microwave due to probability of uneven heating resulting in cool spots.
Due to increased likelihood of Salmonella contamination, eggs should be cooked until whites are set firmly & yolks begin to thicken.
If recipe calls for raw egg (which will not subsequently be cooked), best to use pasteurized egg product
Elderly, infants, very young children, & anyone with compromised immune system should not even consume pasteurized egg Neurotoxins in Seafoods
Neurotoxins in Seafoods Ciquatera: ciquatoxin present in microorganisms in reefs, called dinoflagellates. Most commonly associated with grouper, red snapper, & barracuda, primarily from the Caribbean & South Pacific Islands
Causes nausea, vomiting, abdominal cramps, watery diarrhea, then numbness, shooting pains in legs. Toxin not destroyed by cooking, freezing, digestive enzymes. Seafood Neurotoxins, cont.
Seafood Neurotoxins, cont. Red Tide: may occur between June & Oct on Pacific & New England coasts due to microorganisms In shellfish. Causes burning or prickling sensation in mouth after 5 to 30 minutes, followed by nausea, vomiting, muscle weakness, & loss of feeling in hands & feet. Recovery usually complete. Parasites
Parasites Tapeworms, flatworms, roundworms may enter food & water through fecal material & soil
Usually killed by freezing & always by high temperature
One type of roundworm, found in raw fish, actually bores a hole in a person’s stomach within an hour of consuming it. Frequent incidence in Japan.
Study in Seattle found that about 40% of raw fish samples (from fish used in sushi) contained roundworms, but the worms were dead due to the fish having been frozen. Mad Cow Disease
Mad Cow Disease Bovine spongiform encephalopathy
Suspected of causing at least 90 human deaths in England & France
Appears to have started when cows were given sheep intestines & parts of the spinal cord in their feed
Some of the sheep harbored a type of protein called a prion, that can transmit disease when consumed by a similar species Food Preservation Methods
Food Preservation Methods Main objective is to extend usable life of a food
There are sometimes tradeoffs in regard to nutrient content
Canning Kills all microorganisms using hightemperatureshorttime (HTST) principle
Seals out air
Some destruction of watersoluble vitamins by the heat, but much of loss due to diffusion into canning liquid
Minerals can also diffuse into the liquid
Fatsoluble vitamins not destroyed (heat stable) & do not diffuse into the liquid Food Preservation (cont.)
Food Preservation (cont.) Freezing Nutrient content of frozen foods similar to that of fresh foods, & can be even higher due to fresh foods being picked before ripeness and spending a lot of time in transport & in refrigerator Vitamin C losses occur when tissues are broken & exposed to air (as in chopped broccoli)
Maximum nutrient preservation requires temperature of zero degrees Fahrenheit or lower Food Preservation, cont.
Food Preservation, cont. Drying Vacuum puff drying and freeze drying preserve nutrients much better than methods which use heat
Sulfite additives used for some foods to prevent browning Modified Atmosphere Packaging Either removes air (vacuum) or replaces air with oxygenfree gas
Used for bagged chopped salads, fresh pasta, meats, prepared foods, coffee, etc.
Requires refrigeration to keep the food safe
Increases shelf life & preserves nutrients partly by slowing down enzymeinduced breakdown Steam vegetables or cook them in a
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- Winter '11
- Microwave oven