Transcript Chapter 10: Anorexia Nervosa and Bulimia Nervosa

Chapter 13
Safety of Food
and Water
Foodborne Illness
E. coli: O157:H7
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Greatest risk from viral and bacterial
contamination:
Shiga Toxin
– e.g. E. coli: O157:H7 (199 peo. 26 states fresh
spinach (102 hospitalized, 31 kidney failure)
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Major cause of diarrhea
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Usually results from unsafe food handling in
the HOME
Most Susceptible to Foodborne
Illness
Infants and children
 Older adults
 Those with liver disease, diabetes,
HIV/AIDS, cancer
 Pregnant women
 People taking immunosuppressant agents
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Foodborne Illness
Why so prevalent?
 Consumer interest in eating RAW foods
 Grocery Foods mass produced at
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– Processing plants (see Food Inc. ~ the movie)
 Malfunction Ice Cream Plant in Minnesota 
240,000 Salmonella Bacteria infections~ ice cream:
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Ready to eat foods (foreign countries) e.g.
– Berries (Guatemala)
– Seafood (Asia)
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Anti-biotics in animal feeds
– bacteria develp anti-biotic resistant strains
 Can grow even if exposed to typical antibiotic
Food Safety Agencies
Preservation of Food
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Preventing growth of bacteria
– Salt, sugar, smoke, fermentation, drying
– Limit water available for bacteria growth
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Pasteurization, sterilization, refrigeration,
freezing, irradiation, canning, chemical
preservation
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Aseptic processing
Pasteurized: MILK
&
O.J.
Packaging using sterile conditions, kill all microbes (heat or chemical etc.)
Food Irradiation
(symbol on right)
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(X-rays, UV-rays) - Does not make food radioactive
Breaks down chemical bonds, cell walls, DNA
Controls growth of insects, bacteria, fungi, parasites
Approved for use for raw meats, shell eggs, seeds,
dried seasonings
Safe according to FDA? ~ free radicals generated . .
Radura symbol required
Used in many countries, although still controversial
Why Are Microbes So Harmful?
e.g. Bacillus, Campylobacter, Clostridium, Vibrio, Salmonella
Bacteria everywhere: 1 tsp. soil = 2 billion Bacteria !!!
Challenge Question
What are the TWO Ways that microbes cause food borne illness?
1.
2.
Shiga Toxin
Microorganisms
and
Food Borne
Illness
@ Constant risk of
foodborne illness
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Animation
Microbial Growth vs Temp.
&
Temperature vs Spoilage
Take Break
Food Additives?
 Limit
spoilage
 Prevent
undesirable changes in
color & flavor
 Increase
safety of food distribution
Food Additive Classifications
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Intentional food additives
– Added directly to food
e.g. (Yellow #5, BHT, sulfites, vit. C)
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Incidental food additives
– Indirectly added as contaminant (e.g.,
pesticide residues, rat poo)
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Both are regulated by FDA
Confirming your knowledge
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What 4 compounds constitute 98% of all
additives used in food processing (by
weight)?
1.
 2.
 3.
 4.
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GRAS (Generally Recognized As Safe) List
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Manufacturers do not have to prove safety
– Already regarded as safe,
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FDA
– Responsible for proving that a substance does
not belong on GRAS list
 red dye #3 removed (carcinogen)
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Synthetic chemicals ≤ toxicity of natural
products (Organic/ Natural ≠ safer)
Safety of Additives
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Tested on at least 2 animal species
– Mice, rats
Determine the highest dose that produces no
observable effects (skin, inflammation etc.
 Prorate dose to a human dose (1% of toxicity~ mice)
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– Divide dose by 100 to establish margin of safety
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If additive is shown to cause cancer even at very
high dose, it is taken off the market by FDA
– Several exceptions (nitrates, nitrites  nitrosamines)
-Challenge QuestionWhat is the Delaney Clause?
And what are exceptions?
FDA Approval for New Food
Additive
Must identify new additive
 Give its chemical composition
 State how it is manufactured
 Specify method of measurement
 Outline intended purpose
 Provide proof of safety
 Cannot to be used to deceive public
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Types of Food Additives
Aspartame
Nitrates/Nitrites
Proven to cause cancer
Still used b/c risk is low . .
High Fructose Corn Syrup (HFCS)
~ high levels of Mercury (Hg)
~ High levels of Carbonyl compounds
(Methylglyoxal)
-shown to be high in people w/ Diabetes
Soda Warning? New Study Supports Link
Between Diabetes, High-fructose Corn Syrup
13-Aug-2007, Source:
American Chemical Society (ACS) - Newswise
USDA/FDA Recomendataion:
-eat foods of HFCS in moderation . . .
(MSG)
Confirming your knowledge
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What is the permissible % amount of a food
additive that has shown toxicity to laboratory
animals that can be added to food?
Natural Toxins
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Safrole
Occur naturally in foods
Safrole from sassafras, mace, nutmeg, cinnamon
– (used in Root beer) Known carcinogen – Banned by FDA
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Solanine from potato shoots
– NIH on solanine: never eat potatoes green below the skin.
– nausea, diarrhea, vomiting,
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Mushroom toxins (phalloidin)
– Death cap mushroom
– Amanita phalloides
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Avidin
Tetrodotoxin
Oxalic acid
Herbal teas
solanine
phalloidin
IS Caffeine a Cause for Concern?
Causes anxiety, dehydration, insommnia, increased
heart rate
 Cancers?
 Worsens heartburn (relaxes sphincter muscles in
esophagus)
 Women ~500mg/day increased miscarriages
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– FDA: pregnant women ≤ 2 8oz coffee cup/day
Improves performance in top athletes
 200-300mg/day prudent dose, (2 cups coffee/day)
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– safe/sound for now
theobromine
caffeine
Environmental Toxins
Pesticides vs Organic
Most healthy authorities believe benefits
Outweigh risks (pesticide usage)
 Most toxicity due to chronic vs acute cases
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– extremely small exposure levels avg. human
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Growing evidence (contamination,
destruction of wildlife habitats)
– N. Americans should reduce pesticide use
– (USDA + farmers working towards)
What is a pesticide?
Any substance/mixture intended to prevent,
destroy, repel or mitigate any pest.
 EPA allows 10,000 pesticides
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– (300 active ingredients)
e.g. Roundup: (glyphosate)
-most used herbicide in the USA
- #1 selling in world, 1980
- toxicity to developing embryos
Benachou et al.,
glyphosate
"Glyphosate Formulations Induce Apoptosis and Necrosis in Human Umbilical,
Embryonic, and Placental Cells
2008, Chemical Research in Toxicology
Not all pesticides = bad
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e.g. fungicides prevent aflatoxin
– By product of fungal growth
 Most potent Deadly carcinogens
aflatoxin
-Pesticides prevent billions of food crops destroyed annually
How safe are Pesticides?
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Toxicity based on chronic exposures
– Increased cancer in farm communities
 Lymph, genital, brain, digestive cancers
Some argue pesticide laden food = safer
vs natural product toxins e.g. peanut butter (aflatoxin)
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aflatoxin
Confirming your Knowledge
How can you Reduce Your Exposure to
Environmental Toxins?
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Water Supply
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Water
Bottled water
Artesian
Distilled
Purified
Spring
Mineral
Public drinking water
Challenge QuestionWhat is a good way to limit heavy metal exposure in tap water
from your faucet?
Why should you never run Hot water from the Tap to cook with?
Avoiding Microbes at the Store
Buy frozen, perishable foods last
 Place meats in separate plastic bags
 Don’t buy dented cans
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– Clostridium botulinum toxin
 Most toxic protein known
– LD50 of roughly 0.005-0.05 µg/kg.
– AKA Botox (inhibits Acetylcholine)
–botulinum toxin
Buy only pasteurized milk/cheese
 Buy only what you need (shop 1X week or bi-monthly)
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– buy Fresh
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Avoid buying slimy, brownish, or dry produce
Avoiding Microbes At Home
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Wash hands thoroughly
Keep counters, cutting boards, equipment clean
and sanitized
Prepare raw meat separately
Thaw foods in refrigerator/cold running water/
microwave
Avoid coughing and sneezing over food
Wash fruits/vegetables thoroughly
Remove mold or discard food
Use refrigerated meat in 1-2 days; frozen in 3-4
months
Avoiding Microbes When
Cooking
Thoroughly cook meat, fish, poultry, eggs
 Check for doneness with thermometer
 Cook sprouts until steaming
 Cook stuffing separately
 Eat food right away
 Store leftovers within 1-2 hours (bacteria growth)
 Serve cooked meat on clean plates
 Avoid partially cooking food
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Internal Cooking Temperature
When in Doubt
Throw it out?>
What To Do With Leftovers
Keep hot foods hot & cold foods cold
(<41° F or >135° F)
 Reheat leftovers thoroughly
(165° F)
 Store peeled, cut-up produce in
refrigerator
 Keep refrigerator < 41° F
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Assignments
Diet Analysis 2 due Wednesday (10 pts.)
 Evaluations Wednesday
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Food Inc. Qs (5 pts) Due Friday
 Practice Final Online w/ answers
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Final Exam this Friday (Chapters 6, 8,9,10,11,13,16)
– Challenge & Confirming Your Knowledge Qs (the above)
– Old Final know all Qs and answers