bioaccumulation
the process by which compounds accumulate or build up in an organism faster than they can be broken down or excreted
what are pesticides used for?
to prevent plant diseases and insect infestations
how is public health and the environment protected from pesticides?
the types of pesticides used on crops, how often they may be used, and the amount of reside that may remain when foods reach consumers are regulated
tolerances
maximum amounts of pesticide residues that may remain in or on food
who monitors pesticide residues in foods?
FDA and USDA
what are tolerances set at?
at least 100 times lower than the highest dose that has no harmful effects in test animals
integrated pest management (IPM)
a method of agricultural pest control that combines chemical and non chemical methods and emphasizes the use of natural toxins and more effective pesticide application
organic food
produced using methods that emphasize a reduction in the use of chemical pesticides and fertilizers, the recycling of resources, and the conservation of soil & water to protect the environment
what is the threshold for pesticide residues in organic foods set as?
5% of the EPAs pesticide-residue tolerance
-won't make food risk free
Polychlorinated biphenyls (PCBs)
one group of carcinogenic compounds that pollutes the environment
what were PCBs used for?
manufacture of electrical capacitors and transformers, plasticizers, waxes, and paper.
-runoff contaminated water
-do not degrade
who are PCBs a problem for?
pregnant and lactating women. Can cause nervous system and learning deficits
what other contaminants from manufacturing are found in fish & shellfish?
-chlorade
-strontium-90
-toxic metals
what can cadmium and lead do in the body?
can interfere with absorption of other minerals
what can cadmium do?
can cause kidney damage and can impair brain development
what can mercury do?
damage nerve cells
why are antibiotics and hormones administered to animals?
-improve health
-increase growth
-enhance food production
how do we prevent these chemicals from being passed on to consumers?
both the types of drugs used and when they can be administered are regulated, and animal tissues are monitored for drug residues
what are hormones used for in meat?
to increase weight gain in sheep and cattle and milk production in dairy cows.
a synthetic hormone that has created public concern
bovine somatotropin (bST)
-cows produce it naturally and it stimulates milk production
genetically engineered bST
produced by bacteria and injected into cows to further increase milk production
what is one of the easiest ways to reduce risk of contaminants and chemicals in food?
to eat a variety of foods, choose organic or locally grown foods
how to reduce consumption of chemicals in fish?
remove the skin, fatty material, and dark meat from fish. use cooking methods such as broiling, poaching, boiling, and baking, which allow chemicals from fatty portions of fish to drain out
food additive
a substance that is intentionally added to or can reasonably be expected to become a component of a food during processing
-FDA regulates the types & amounts that may be present in food
accidental contaminants
unexpected substances that enter food
-not regulated
what is one of the oldest methods that ensures food is safe?
cooking
pasteurization
process of heating food products in order to kill disease-causing organisms
aseptic processing
placement of sterilized food in a sterilized package using sterile process
what does lowering the temp by refrigerating or freezing a food do?
does not kill microbes, but it preserves the food and protects consumers bc it slows or stops the microbial growth
carcinogenic chemicals produced during the cooking of meats
-polycyclic aromatic hydrocarbons (PAHs)
-heterocyclic amines (HACs)
*
not regulated by FDA
*
PAHs
formed when fats drips on a grill and burns... they rise with smoke and are deposited on the surface of the food
how can PAHs be prevented
by using lower-fat meat or using aluminum foil to prevent fat from dripping on the coals
HCAs
produced by the burning of AAs and other substances in meats and are formed during any type of high-temperature cooking
how can HCA formation be reduced
by precooking meat, marinating meat before cooking, cooking at lower temps, and reducing cooking time by using smaller pieces of meat and avoiding overcooking
acrylamide
formed as a result of chemical rxns that occur during high-temp baking or frying, particularly in carb-rich foods.
where are the highest levels of acrylamide found?
in french fries and snack chips
smaller amounts of acrylamide
coffee & foods made from grains
food irradiation (pasteurization)
process that exposes foods to radiation in order to kill contaminating organisms and retard the ripening and spoilage of fruits & veggies
-treated as a food additive
modified atmosphere packaging (MAP)
uses plastics or other packaging materials that are impermeable to oxygen
-air inside packaging is vacuumed out
direct food additives
substances that are intentionally added to foods
prior-sanctioned substances
exempt from regulation bc that FDA and USDA has already determined them to be safe
-nitrates and nitrites
second category that is not subject to food additive regulation consists of :
generally recognized as safe (GRAS) based either on their history of use in food before 1958 or on published scientific evidence
how do we make sure that additives are safe in our food?
they are added 100 times below the highest level has has been shown to have no harmful effects
Delaney Clause
states that any substance that induces cancer in either an animal species or human at any dosage may not be added to food