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28 Cards in this Set
- Front
- Back
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Definition of Food Toxicology
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a substance that can elicit a detrimental effect in a biological system
Water LD50= 90ml/Kg~30 cups or 6,750g/75g |
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Salt
Caffeine Solanine HCN Tetrodotoxin Botulinum |
LD50 mg/75kg body weight
Salt Processed Foods 75,000 Caffeine Coffee 15,000 Solanine Potatoes 210 HCN Pits 75 Tetrodotoxin Puffer Fish 1 Botulinum "Bloated" cans .075 |
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Endogenous Toxicants
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Biological raw materials of food
produced by plants/animals for cell protection again pests, pathogens mostly in fruits, vegetables, herbs ex: safrole, methyl glyoxal (AGE), carotatoxin (carrots), myristicin (nutmeg, parsley, dill), psoralens (citrus, Angelica), cyanide (seeds of apple, apricot, cherries, plums) |
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Naturally Occurring Toxicants
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Microbial contamination
Toxic in food (intoxication) v.s Toxin in victim (intoxification) Ex: C. Botulinum, Mycotoxins, Dinoflagellates (Algae) |
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Synthetic Toxicants
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Synthetic contaminants
Ex: pesticides, antibiotics, growth promoters |
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Toxic Assessment
Risk Assessment |
Risk Assessment: determine severity/toxicity of chemical hazards, used to regulate food safety
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Toxic Assessment
Dose Response Assessment |
Dose Response Assessment:
Concentration: how much is toxic? Acute Effects: one time exposure to large doses, quick to determine Chronic Effects: low level exposure over time, long, repeated exposure, slow, needs large number of subjects |
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Toxic Assessment
Exposure Assessment |
Exposure Effect: what is the risk of exposure? amount absorbed when exposed to target
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Toxic Assessment Methods
Dose-Response Curve |
threshold value, maximum effect, strength (slope)
ED50 Effective Dose, causes adverse effects in 50% of tested animals LD50 Lethal Dose, causes lethality in 50% in tested animals (ex. 100ug/Kg=toxic, 1000mg/Kg= non-toxic) x axis dose y axis effect threshold beginning of curve maximum top of curve |
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Toxic Assessment
Epidemiological Studies |
indicates frequency of occurrence
geographical distribution establish link between frequency and distribution can also indicate what is good for a population (french paradox) but, other variables may impact toxin |
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Toxic Assessment
Bioassays |
whole animal studies (as close to humans as possible)
advantages: easy, high doses, good environmental controls disadvantages: extrapolate to humans, dose effect |
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Bioassays
Cell Culture Studies |
specific cell types
test specific cell types to establish toxic effects |
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Bioassays
Specific Carcinogen Tests |
Ames Test
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Endogenous Toxicants (Biological)
1. Flavonoids |
flavones, flavonols (auercetin), flavonois, flavonones, leucoanthocyanins, anthocyanins, catechins (EG, EGC)
fruits, tea, vegetables, soybean impart color, antioxidative effects LD50 quercetin (oral, rates) 160mg/kg (12,000mg/75kg) beneficial at naturally occurring levels |
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Endogenous Toxicants (Biological)
2. Goitrogens (goiter development) |
Thiocyanates, Indole 3-carbinol
Vegetables ex: cruciferous/brassica, alliums (thiocyanates), rapeseed (progoitrin) |
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Endogenous Toxicants (Biological)
3. Coumarins |
Psoralens (light oversensitivity), bergapten (skin inflammations)
Xanthotoxin, isopimpinelin Citrus fruit peels, Angelica, herbs |
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Endogenous Toxicants (Biological)
4. Cyanide |
HCN (LD50~1mg/kg) higher for native form (LD50=200-500 mg/kg)
Seeds of many fruits (bitter almonds, apples-amygdalin, cassava, lima beans-linamarin, sorghum-dihurrin) cause muscle weakness, headaches, chest tightening, anemia, death |
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Endogenous Toxicants
5. Herbs |
Alkaloids block breakdown of acetylcholine by inhibiting acetylcholinesterase
stomach aches, nausea, vomiting, breathing difficulties, death, liver cirrhosis, mutations Pyrrolizidine Alkaloids, safrole, eucalyptol (rosemary, sage, vicks) myristicin (carrots, nutmeg) comfrey, chamomile, rosemary, sage, sassafras, mac, nutmeg |
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Endogenous Toxicants
6. Mushrooms (3 types of poisoning) |
1. Protoplasmic: (affect organs, liver and kidneys>necrosis)
ex: Amanatins (from amanita) hydrzines (gyrometrin from gyrometra) orelianine (from cortinarius) 2. Neurotoxic: (primarily CNS) ex: muscarine (from Inocybe) Ibotenic Acid, muscimol (from Amanita), psilocin, psilocibin (from Psilocybe) cause drunken state, hallucinogenic 3. Gastrointestinal (GI irritation) ex: horse mushroom, jack o'lantern, green gill |
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Endogenous Toxicants
7. Fatty Acid |
erucic acid in rapeseed oil, LEAR
arachidonic acid n-6 in red meats, eggs, dairy, duck, tilapia omega 3's (EPA, DHA, ALA)>Oxidative Stress |
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Endogenous Toxicants
8. Sugar |
Fructose > AGE > Carbonyl Stress
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Endogenous Toxicants
9. Animal/Insect Toxins/Venoms |
Tetrodotoxin (pufferfish), hemotoxin (snakes), psalmotoxin (tarantula)
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Endogenous Toxicants
10. Lectins (sugar binding proteins) |
gastrointestinal damage, impacts IgG Immune responses and hemagglutination
grains>especially wheat and wheat germ but also quinoa, rice, buckwheat, oats, rye, barley, millet, corn legumes> all dried beans including soy and peanuts dairy>when cows are fed grains instead of grass, research shows transference of lectins into breast milk and dairy and potentially more harmful in pasteurized, processed milk because of the reduction of IgA an immunoglobilin that binds dangerous lectins Nightshade>family plants (potatoe, tomato, eggplant, pepper) |
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Food Allergens
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US: Affect 2% Adults 5% Infants/Children 150 annual mortalities
Food Allergen Labeling and Consumer Protection Act 2004 Food Allergens: milk, eggs, peanut, treenuts, fish, shellfish, soy, wheat (bee pollen, royal jelly) Symptoms: skin irritations, GI disorders, anaphylaxis |
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Allergen (antigen) in blood > triggers > T cells/T lymphocytes > stimulate > B Cells/B Lymphocytes > produce > IgE antibody (produced by plasma cells, A specialized type of B-cells) > bind to Mast Cells (WBC) >
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activate IC > intracellular Ca++ increase > triggers > degranulation> releases > histamine, heparin > swelling, skin rash, mucus secretion, asphyxiation
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Food Intolerances
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sensitivity to foods
non-life threatening inability to chemically breakdown particular foods enzyme deficiency in GI tract Aspartame, MSG, Sulfites, Benzoates, Gluten, Lactose, Tatrazine Allergies when only IgE involved |
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Food Aversion
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psychological condition
people who despite non-responsive testing still believe certain foods disagree with them |
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Sufficient Challenge
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phenomenon of beneficial effects from exposures to trace amounts of toxic chemicals
dose at LD5-LD20 HF Smyth- toxicologist, animals fed toxins would get healthier at a certain point before showing signs of toxicity Defense system needs to be exercized/challenged periodically or they become weak (like muscles that atrophy with inactivity) Food Cosmet Toxicol 1967 Feb 5 (1) 51-8 no guarantee that humans will have a beneficial "sufficient challenge" based on a test animals reaction dose should be kept as low as possible |
