Course:FNH200/Lessons/Lesson 12/Page 12.3

12.3 Types of Toxicants

Food toxicants can be classified in a variety of ways. The scheme in Table 12.1 is based on origin or occurrence of the toxicants, namely as naturally occurring toxicants (either constituents or contaminants), or environmental toxicants.

Table 12.1.Classification of some possible food toxicants

Naturally Occurring Toxicants: Constituents	Naturally Occurring Toxicants: Contaminants	Environmental Toxicants
Cholinesterase inhibitors: solanine in potatoes Cyanogenic glycosides: amygdalin in apple seeds Glucosinates: Sinigrin in cabbage Protease inhibitors: protease inhibitors in soy beans Nitrites: Green leafy plants Allergens: beta-lactoglobulin in milk, peanut proteins, soy proteins	Mycotoxins: Aflatoxin Patulin Ochratoxin A Vomitoxin Zearalenone Examples: aflatoxin in mouldy peanuts, vomitoxin in wheat Bacterial toxins: botulinum toxin Staphylococcal toxin Seafood Toxins: Histamine Saxitoxin Domoic acid Tetrodotoxin	Food packaging residues: Monomers of plastic resins Pesticide residues: Herbicides Insecticides Fungicides Example: malathion residues on fruit Heavy metals: Lead Mercury Cadmium Examples: lead in vegetables; mercury in large ocean fish (eg. swordfish) Animal drugs: Antibiotics Hormones Examples: penicillin in milk Radioisotopes: from soil or from radioactive fallout