Download Chapter 19: Consumer Concerns

Chapter 19: Consumer Concerns
Food safety monitored by FDA, USDA’s Food Biosecurity Action Team. Many
foods toxic in excess, few hazardous.
I. Foodborne Illness
Biggest concern. Food poisoning potentially fatal. Caused by pathogens:
disease-causing organisms. Most are microbes.
(A) Bacteria: examples= Salmonella. E. Coli. Toxins release by some,
e.g. Clostridium (botulism).
(B) Viruses Norwalk in seafood, Hepatitis A.
(C) Parasites Giardia, Trichinella, tapewoms, Ascaris.
(D) TSEs = transmissible spongiform encephalopathogens. Mad Cow,
Creutzfeldt-Jacob, Scrapie (in sheep).
Countered with pasteurization, heating, packaging, preservatives and radiation.
Approximately half of travelers get diarrhea from unfamiliar pathogens.
II. Nutritional Adequacy
Aided by the FDA which requires labeling and establishes dietary guidelines.
Nutritional losses minimized with refrigeration, airtight containers, steaming
vegetables.
III. Environmental Contaminants
Severity based on persistence, bioaccumulation. Past problems: methylmercury
in fish, PBB & PCB exposures in livestock feed and rice oil.
IV. Natural Toxicants
Goitrogens in cabbage family may enlarge thyroid. Cyanide in lima beans and
peach pits. Solanine in potatoes.
V. Pesticides
A problem with weakened immune systems. Tolerated well by most. Use
regulated by FDA and EPA. Imported foods bypass US controls but inspected
before sale here. Alternatives: rotating crops, natural pesticides (nicotine),
marigolds, predators (ladybugs, mantids)- more suitable for small gardens.
Organic produce not healthier for most, contain natural contaminants, pathogens,
spoil faster.
VI. Food Additives
Most are preservatives. FDA updates GRAS: ‘generally recognized as safe’ list.
Delaney Clause addresses cancer risk – no defined limits has created false
alarm. Benefits must outweigh risks, for example nitrites in lunch meats prevent
spoilage.
(A) Antimicrobial Agents = salt, sugar, nitrites, potassium sorbate.
(B) Antioxidants = ascorbic acid (Vitamin C), sulfites, BHA, BHT.
(C) Color & Flavor enhancers – spices, MSG.
(D) Texture and Stability – emulsifiers, gums.
(E) Nutrient Additives – iodine, Vitamins A & D, iron……
Indirect additives make their way into food unintentionally.
Acrylamide in French fries (or other carbohydrates fried at high
temperatures); microwave packaging (Styrofoam); dioxins from bleached paper
(trace amounts in coffee filters); decaffeinated coffee- done with methylene
chloride (toxic); hormones like bGH (bovine growth hormone)- still in cow’s
natural range, no effect on humans.
Antibiotic overuse has helped create resistant bacteria- huge crisis.
VII. Water
May contain impurities. Surface water or ground water (wells). Latter
contaminates more slowly but with longer-lasting effects. Public water usually
has chlorine. Home treatment removes copper, sulfur and more. Carbon
removes the chlorine. Reverse osmosis membrane also filters sodium, arsenic
and more microbes.
Bottled water comes from a variety of sources; may not be better than tap.
VIII. Food Biotechnology
Genetic engineering to extend shelf life of foods (tomatoes), improve nutrition
(complete soy protein, golden rice with beta carotene), create pest resistance,
create temperature-tolerant plants.