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Explore the world of food contaminants, their classification, representatives, and toxic effects. Learn about natural and human-induced contaminants, including mycotoxins, toxins in plants, and substances from human activity.
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CONTAMINANTS OBJECTIVES 1. What are contaminants? 2. Classification; 3. Representatives.
CONTAMINANTS 1 1. Food toxicology, terms, perspectives and problems • What is a contaminant? • Which substances are contaminants? • What we should look to avoid? 1564г. Paracelsus: “Everything is poison! Merely the dose determines the effect of a substance – poisonous or medicinal.” - Toxic substance and toxic effect
! CONTAMINANTS 3 1. Food toxicology, terms, perspectives and problems - Terms: - acute toxicity – toxic response induced by single exposure (intake) of toxic substances (ex. HCN – 50-60 mg); lethal dose - LD50 - chronic toxicity – continuous (prolonged) exposure (intake) of toxic substances; tumor dose - TD50 - MTD (maximum tolerated dose) - ADI (acceptable daily intake)
CONTAMINANTS 6 2. Classification 2.1.Inherent toxicants: a). Natural components of the foodstuffs; b). Naturally present contaminants in foodstuffs: - with microbial, plant or animal origin derived as natural metabolites; - with non-microbial, plant or animal origin as a result of consumed toxicants by the organisms. 2.2. Contaminants by human activity: a). Food additives; b). Agrochemicals and residue; c). Toxic metals; d). Substances derived from packings; e). Toxicants that are formed during food preparation; f). Toxicants resulted from incidents.
CONTAMINANTS 7 3. Representatives 3.1. Naturally present contaminants in foodstuffswith microbial, plant or animal origin derived as natural metabolites 3.1.1. Plant - protease inhibitors - hemagglutinins (lectins) - saponins solanine
CONTAMINANTS 8 3. Representatives 3.1. Naturally present contaminants in foodstuffswith microbial, plant or animal origin derived as natural metabolites 3.1.1. Plant - cyanogenic substances Amygdalin - in bitter almonds (but not in sweet almonds) cherries, apples, plums, peaches, apricots. Linamarin - leaves and roots of cassava, lima beans, flax. Dhurrin - sorghum varieties
CONTAMINANTS 9 3. Representatives 3.1. Naturally present contaminants in foodstuffswith microbial, plant or animal origin derived as natural metabolites 3.1.1. Plant - phytoalexins - act as toxins to the attacking organism Allixin (from garlic) - anti-oxidative effects, anti-microbial effects, anti-tumor promoting effects, inhibition of aflatoxin binding. - others gossypol – cotton seeds
CONTAMINANTS 10 3. Representatives 3.1. Naturally present contaminants in foodstuffswith microbial, plant or animal origin derived as natural metabolites 3.1.2. Animal - Toxins produced by marine animals tetrodotoxin – pufferfish (fugu); extremely toxic Ocadaic acid (phycotoxin – toxin produced by phytoplanktons)
CONTAMINANTS 11 3. Representatives 3.1.3. Mycotoxins
CONTAMINANTS 12 3. Representatives 3.1.3. Mycotoxins Aflatoxin B1 Sterigmatocystin Ochratoxin A Patulin Zearalenone
CONTAMINANTS 13 3. Representatives 3.1.4. Microbial Botulinum toxin-BTX (Clostridium botulinum); tetanus toxins – tetanospasmin, tetanolysin (Clostridium tetani); Staphylococcus aureus toxins, Escherihia colietc. Botulinum toxin DL50 estimated for humans 1.3÷2.1 ng/kg intravenously or intramuscularly and 10÷13 ng/kg when inhaled. Arnon, Stephen S.; Schechter R; Inglesby TV; Henderson DA; Bartlett JG; Ascher MS; Eitzen E; Fine AD; Hauer J; Layton M; Lillibridge S; Osterholm MT; O'Toole T; Parker G; Perl TM; Russell PK; Swerdlow DL; Tonat K; Working Group on Civilian Biodefense (February 21, 2001). "Botulinum Toxin as a Biological Weapon: Medical and Public Health Management" (PDF, 0.5 MB). Journal of the American Medical Association 285 (8): 1059–1070.
CONTAMINANTS 14 3. Representatives 3.2. Contaminants by human activity 3.2.1. Food additives: - nitrates, nitrites; - sulfites; 3.2.2. Agrochemicals and residues - pesticides, insecticides, fungicides, herbicides, hormones, antibiotics 3.2.3. Toxic metals - lead, mercury, arsenic, tin, aluminium...
CONTAMINANTS 15 3. Representatives 3.2. Contaminants by human activity 3.2.4. Substances derived from packings – tin, lead, benzophenone (UV- protection of plastics)-allergen, bisphenol A (obtaining of plastics, polycarbonates (CDs, DVDs) and epoxy resins); Perfluorooctanoic acid ( microwave popcorn bags; PTFE (Teflon) Bisphenol A Perfluorooctanoic acid
CONTAMINANTS 16 3. Representatives 3.2. Contaminants by human activity 3.2.5 Others – radionuclides, benzopyrenes, dioxins, PCB - polychlorobiphényles (TCDD) dioxins 2,3,7,8-tetrachloro dibenzo-p-dioxin benzo[a]pyrenes Irish pork crisis of 2008 PCB - polychlorinated biphenyls
CONTAMINANTS 17 4. Other aspects https://www.youtube.com/watch?v=U6v8eqEsoKY – food fraud