FSN 375 Chemical Hazards

how does the FDA define a chemical hazard?

chemical hazards, including radiological hazards, substances such as pesticide and drug residues, natural toxins, decomposition, unapproved food or color additives, and good allergens

how can chemical hazards be introduced?

unintentionally or intentionally introduced for economic game

what are the 4 types of chemical hazards in foods?

inherent toxins, natural and environment contaminants, process and storage-derived contaminants, deliberately added contaminants

what are inherent toxins?

chemicals that are regular constituents of the food

how can inherent toxins be increased?

as a response to stress

what are 5 inherent toxins?

lectins, glycoalkaloids, enzyme inhibitors, cyanogenic glycosides, allergens

what macronutrient are lectins?

proteins

what do lectins exhibit? what does this cause?

high binding affinity for carbohydrates -\> impairs protein digestion and cause malabsorption of other nutrients (go through GI tract instead of being absorbed)

what symptoms do lectins cause?

diarrhea, leaky gut (cause perforations in intestine)

what foods contain lectins?

soybeans, lentils, peas, peanuts, tomato skin, eggplants

how do you inactivate lectins?

lectins are thermolabile (thermal inactive); inactivated by heat

when are glycoalkaloids produced?

as a natural plant defense (when potatoes turn green/sprout, glycoalkaloids are produced)

what do symptoms do large amounts of glycoalkaloids cause?

abdominal pain, vomiting, diarrhea, confusion, fever, hallucination, paralysis, convulsions, death

how do glycoalkaloids taste?

bitter

are glycoalkaloids heat stable?

yes

what are increased levels of glycoalkaloids a result of?

stress factors during growth, post harvest due to handling, light

what foods have glycoalkaloids?

potatoes, eggplants, berries

true or false: enzyme inhibitors are toxic

false, enzyme inhibitors themselves are not toxic

what important role do enzyme inhibitors have?

protein digestion (proteases)

what does the isolation of enzyme inhibitors cause?

prevents break down of proteins

what enzyme inhibitor is most commonly and widely studied?

trypsin inhibitor (trypsin -\> skin irritation)

what processes cause enzyme inhibitors to go away?

cooking, fermentation, precipitation, washing, filtration

what foods are cyanogenic glycosides found?

cassava, bitter almonds, stone fruit kernels, apple seeds, mango pit

what is a cyanogenic glycoside?

sugar molecule linked to a cyanide group

why is cyanide deadly?

prevents body's ability to use oxygen

what process results in the release of cyanide?

enzymatic hydrolysis (crushing, digestion)

how do you prepare cassava so that it's no longer dangerous?

leaching, washing, boiling, uncovered fermentation (let the cyanogenic glycosides evaporate out)

symptoms of cyanogenic glycosides

acute renal failure, cardiac pulmonary arrest

what are allergens?

proteins that trigger an immune response

symptoms of allergens

rash to anaphylaxis to death

what percentage of allergic reactions are from the big 9?

90%

what does FALCPA stand for? when was it established? what agency is it under?

food allergen labeling and consumer protection act, 2004, FDA

what are natural and environmental contaminants?

-contaminants that the food acquires from its surroundings during its growth (ex: nitrogen in soil)
-not specifically required by the plant or animal

what happens when natural and environmental contaminants are too high?

can be toxic to humans

what are natural and environmental contaminants controlled by?

the environment

true or false: many natural and environmental contaminants cannot be processed out

true, when in environment for too long, they can become inherent

4 natural contaminants

mycotoxins, shellfish toxins, histamine, tetrodotoxin

3 environmental contaminants

pesticides, dioxins/polychlorinated biphenyls (PCBs), heavy metals

where do dioxins/polychlorinated biphenyls come from? what is their main source?

-byproduct of combustion processes, cigarette smoke, industrial process
-main source is from meat and milk (cattle inhale dioxin from air, dioxin becomes concentrated in their muscles)

relationship between dioxins/PCBs to environment and food? are they long lasting?

-widespread in environment and found in all food
-long lasting contaminants

concerns with dioxins/pcbs - excessive exposure

skin disease, excessive body hair, possible mild liver damage

concerns with dioxins/pcbs - high level/long term exposure

increased cancer risk

concerns with dioxins/pcbs - low level/long time exposure

reproductive and developmental effects

heavy metals - lead; where is it found? contaminated products? what can it lead to?

-soil, paint, pipes, leaded gas
-candy, vitamins, drinking water, packaging material
-behavior and learning problems, slowed growth (autism), hearing problems, headaches

heavy metals - mercury; where is it found? what animals can accumulate it?what can it affect?

-naturally in the environment (ocean) and a result of pollution
-shark, swordfish, king mackerel
-cognitive thinking, memory, attention, language. fine motor, visual spatial skills

heavy metals - arsenic; where is it found? what can it affect/lead to?

-naturally occurring in the environment (rice, fuel, soil)
-skin disorders, cancer (skin, bladder, lung), intellectual development in children

what are mycotoxins?

toxins produced by molds (Penicillium, Fusarium, Aspergillus (produces Alfatoxins))

what foods can have mycotoxins?

nuts, dried fruits, grains, milk

when are mycotoxins produced?

prior to harvest or during storage

what do low vs high levels of mycotoxins cause?

-low: cancer
-high: death

3 mycotoxins

aflatoxin, patulin, fumonisins

what is the most important factor for fungi growth?

water activity

how to control mycotoxins?

understand sources of supply, growth conditions, establish specifications

is heat effective against mycotoxins?

no

are shellfish toxins formed by the shellfish?

no, they are the result of algae

what are the 4 types of shellfish poisoning?

paralytic (PSP), neurotoxic (NSP), diarrhetic (DSP), amnesic (ASP)

PSP symptoms

neurological symptoms, tingling, numbness, respiratory paralysis

NSP, DSP, ASP symptoms

gastrointestinal symptoms, some neurological

how to control shellfish toxins?

harvesting, avoid algae bloom

true or false: shellfish toxins can be readily eliminated by heat

false

when is histamine/scombrotoxin released?

released by cells in response to allergy/injury

where is histamine/scombrotoxin found?

in fish as a result of bacterial growth

what is histamine/scombrotoxin generally due to?

inadequate post-harvest time/temp control

explain how histamine is formed

dead bacteria forms histidine decarobxylase (enzyme) and combines with histidine (protein already present) to form histamine

is histamine/scombrotoxin inactivated by cooking, canning, or freezing?

no

when do symptoms occur from histamine?

disease onset immediate; 30 min

histamine symptoms

tingling/burning of mouth, rash, drop in blood pressure, headaches, itching, nausea, vomiting, diarrhea

where is tetrodotoxin found?

reproductive organs, liver, intestines, skin of pufferfish/fugu

how is tetrodotoxin formed?

unknown (metabolic product of host? bacteria?)

mortality rate of tetrodotoxin

50% mortality, death 20 min - 8 hrs

symptoms of tetrodotoxin

numbness lips/tongue, lightness/floating, nausea, vomiting, difficulty walking, paralysis, speech impairment, death, may be conscious lucid before death

can tetrodotoxin be destroyed by heating?

no

who regulates pesticides?

EPA (reviews data, registered/licensed, establishes tolerance/action levels)

who is responsible for enforcing pesticide tolerances?

FDA/USDA

how to control pesticides?

control; close working relationship between suppliers and growers, follow EPA guidelines, FDA training program for countries that produce produce for US

what are process and storage-derived contaminants that result of?

high temps or prolonged storage (water activity, pH, temp of environment)

4 process and storage-derived contaminants

acrylamide, furans, benzene, BPA

how is acrylamide formed?

process derived, natural chemical reaction between sugar and asparagine in high heat (C6H12O6 in french fries)

what is acrylamide made up of?

sugars + amino acid (asparagine)

what does acrylamide cause?

cancer in animals

what is acrylamide found in?

foods made from plants (potatoes, grain, coffee)

where is furan used?

chemical manufacturing industries

what does furan cause?

cancer in animals

how do scientists think furan forms in food?

during traditional heat treatments (cooking, jarring, canning)

how to lessen furans?

may evaporate when foods are heated in open containers

sources of furan

forest fires, construction

what is benzene?

6 ringed structure

where is benzene found?

chemical released into air from automobiles, burning coal and oil, used in industrial products (dyes, detergents, some plastics)

what can stimulate the formation of benzene?

time in elevated temps, light exposure during shipping, handling, storage

what food is benzene found in?

beverages (drinking water is allowed 5 ppb)

what can benzene cause?

cancer in humans

is benzene a volatile? does it evaporate?

not a volatile; settles down because it is a heavy compound (does not dissolve/evaporate)

what is bisphenol a?

industrial chemical found in hard plastic bottles and metal food cans

what concern surrounds BPA?

concern about impaired development (brain, behavior, and prostate gland in fetuses, infant, and young children)

when was BPA banned for certain products?

banned in 2012 in baby bottles and spill proof cups

deliberately added contaminants motives

financial gain, harm consumers (political motives; ex: Indian guru in the 80s gave Salmonella to other party)

deliberately added contaminants - what is melamine? why was it used/what was it added in? what can it cause?

-industry synthesized chemical used in laminates, coatings, plastics; NOT naturally occurring in foods
-added to infant formula in China to increase "protein" concentration since its structure is similar to amino acids
-can cause crystals in urine

deliberately added contaminants - cumin incident

-contaminated in 2015 with peanut shells and almond husks (grinded in a way to look like cumin, increase weight of product)
-largest recall of an allergen in spice (FDA)
-cumin crop expected yields to be 40-50% less
-purposeful economically motivated adulteration

what kind of chemical hazard was the 2011 Japan Tsunami (Fukushima) incident?

radiological chemical hazard

what are 3 unavoidable poisonous or deleterious substances?

alfatoxins, paralytic shelfish toxins, mercury