FN110 Session 2
Introduction to Nutriton
Semester Fall 1998
Nancy J. Gustafson

Chapter 16 Notes

Weighing Food Safety Risks

I. Risk-benefit analysis-potential risks v. benefits

II. Terms
	A. food-borne illness-transmitted through food
	B. pathogens-organism capable of causing disease
	C. Toxins-substances causing harm
	D. threshold effect-no effect up to a certain amount

III. Safeguards
	A. federal agencies
		1. Food and Drug Administration (FDA)
			a. safety of foods except red meat, poultry, eggs
			b. food additives/colors
			c. food labels
			d. food sanitation
			e. inspects plants/imported foods

		2. U.S. Dept of Agriculture (USDA)
			a. safety of red meats, poultry, eggs

		3. Environmental Protection Agency (EPA)
			a. pesticide levels
			b. water quality		
	
		4. Hazard Analysis Critical Control Point (HACCP)-system that prevents food-borne hazards by
		    studying food production systems
			a. identify points where hazards can be prevented
			b. establish measures to prevent

	B. state/local government
		1. dairy products
		2. foods sold in restaurants, stores

	C. consumer
		1. evaluate safety/risks
		2. handle food carefully at home

Pathogens/Parasites in Foods-bacteria, viruses, molds, parasites, toxins

I. Effects
	A. for most, flu-like symptoms
	B. more severe reactions in young, elderly, compromised immune system
	
II. Bacteria
	A. responsible for most food-borne illness
		1. grow in intestinal tract, or
		2. produce toxins that make us sick
	B. sources
		1. present on food, grows
		2. cross-contamination
	C. Bacterial food-borne infections
		1. salmonella
			a. feeces, contaminated water
			b. poultry, eggs most commonly involved
			c. wash food, utensils, cook thoroughly
		2. campylobacter jejuni
			a. cook, store cold
		3. listeria monocytogenes
			a. commonly involves dairy products
			b. destroyed by pasteurization 
		4. vibrio vulnificus
			a. mostly from shellfish in contaminated water
	
	D. bacterial food-borne intoxication
		1. illness from the toxins the bacteria make
		2. staphylococcus aureus-coughing, sneezing
		3. clostridium perfringens
			a. soil, GI tract
			b. makes spores, hard to kill
		4. E coli
			a. GI tract, so fecal contamination
			b. different strains
			c. 1993 fast-food undercooked hamburger outbreak
			d. cook thoroughly
		5. clostridium botulinum
			a. deadliest toxin
			b. improperly home-canned food
			c. killed by boiling
			d. infant botulism-spores germinate in GI

III. Viruses
	A. fecal contamination
	B. raw shellfish
		1. Norwalk virus
		2. killed by heat
	C. hepatitis A
		1. highly contagious
		2. killed by heat, chlorination

IV. Molds
	A. produce toxins
	B. potent mutagens and carcinogens
	C. aflatoxin, ergot

V. Parasites
	A. enter body through diet
	B. Giardia lamblia
		1. food/ water contaminated with feeces
		2. hikers get from water with animal feeces
	C. trichinella spiralis-raw or undercooked pork
	D. raw fish-larvae of roundworms, flatworms, tapeworms, fluke
  	
Preventing food-borne illness

I. select safe foods
	A. check packaging, dates, 
	B. disgard bulging cans

II. store food properly
	A. Cold foods <40 degrees refrig, < 0 freezer
	B. hot foods hot, > 140 degrees
	C. thaw in refrig, microwave, running water

III. prepare, serve food safely
	A. wash all
	B. avoid cross-contamination-cutting boards
	C. cook food thoroughly
	D. don't eat eggs raw

IV. handle leftovers safely
	A. refrig or freeze immediately
	B. divide large portions

V. away from home:
	A. restaurants
		1. hot food steaming
		2. cold on ice
	B. salad bars
		1. customer contamination
		2. sneeze bars, clean plates
	C. picnics
		1. avoid eggs, mayonnaise
		2. choose foods that will last without refrig
	D. lunches
		1. keep cold
		2. throw out unused

Chemical toxins in foods

I. Pesticides
	A. higher concentration in animals
	B. acute versus long-term problems
	C. regulating use
		1. weight risks and benefits
		2. tolerance levels set, regulated
	D. reducing pesticide risk
		1. developing safer pesticides
		2. integrated pest management-chemical and 
		non-chemical techniques
		3. pest-resistant crops, natural toxins
		4. organic farming
			a. grown without pesticides
			b. may contain traces of pesticides from other sources
			c. improperly treated animal manure may contain other bacteria
II. Antibiotics and hormones
	A. USDA regulates
	B. amounts low, benefits of food outweigh risks
	C. risk of antibiotic resistant bacteria
	D. bovine somatotropin (bST) 
		1. genetically engineered bST
		2. to increase milk production in cows
		3. FDA review shows no health effects
		4. economic consideration

III. Industrial wastes
	A. Polychlorinated biphenyls (PCB's)
		1. runoff from manufacturing 
		2. to water, to fish, to humans
		3. problem in great lakes area
	B. chlordane to control termites
	C. toxic metals: cadmium, lead, mercury

IV. reducing risks
	A. choose domestically-grown, locally-grown
	B. wash, peel (but then less fiber, micronutrients)
	C. variety of fish, clean waters
	D. trim fat

Food Technology

I. benefits, better:
	A. food availability
	B. food safety
II. Terms
	A. food additives-becomes a component of food during processing 
		1. direct additives-intentionally added
		2. indirect additives-unintentionally enters foods 
		3. all carefully regulated
	B. accidental contaminants-improperly handled, unexpected

III.  Regulating food
	A. FDA responsible for safety
	B. sets standards of identity for foods
	C. testing
		1. Since 1958, manufacture must prove safety to FDA
	D. GRAS list (generally recognized as safe)
		1. additives before 1958 exempt form regulations
		2. must prove unsafe before it can be removed
		3. cyclamates were removed, cancer risk
	E. Delaney Clause, 1958 Food Additives Amendment--prevents adding anything to food that causes
                   cancer in humans or animals in any amount

IV. Direct Food Additives
	A. to maintain nutritional quality 
	B. to maintain product quality
		1. preservatives
			a. nitrates, can form nitrosamines
			b. sulfites
	C. aid in processing or preparation (emulsifiers, stabilizers, thickeners, texturizers)
	D. color and flavor	
		1. certified colors
		2. exempt colors	

Processing/Packaging

I. Methods
	A. long-used methods-drying, smoking, salting, sugar, fermentation
	B. temperature
		1. pasteurization
		2. cooking
		3. refrigeration
		4. freezing
II toxins during cooking
	A. polycyclic aromatic hydrocarbons (PAH's)
	B. heterocyclic amines

III. packing safely
	A. aseptic processing
	B. vacuum packed
	C. modified atmosphere packing

IV. packaging contamination
	A. plastics, paper, ink
	B. improper use (ex. bread bags)

V. Irradiated Foods
	A. high dose radiation kills microorganisms, slows ripening
	B. produces unique compounds, not known to be a risk

VI. Biotechnology
	A. using genetic engineering to alter DNA of plants, animals to produce new traits, enhance desirable traits
	B. identify gene responsible for trait
	C. clone gene
	D. add cloned gene to target plant/animal
	E. benefits-quality, quantity, safety
	F. risks
		1. no different from other foods
		2. other concerns
			a. introduce trait to wild plant, animal
			b. ethical, religious issues

Academic Dishonesty/Plagiarism:
Work in this course must adhere to the Code of Academic Responsibility and Conduct as cited in "Rights & Responsibilities of Community: A Code of Student Conduct" (1993) pp. 29-30.