toxic substances

Toxic Substances

Toxicant is a substance which when ingested at high levels produces harmful actions on Biolog mechanisms.
Natural toxicants can occur as contaminants of natural food products or as normal components of such foods. Contaminants can be of microbiological origin, such as toxins produced by bacteria, or they can be taken up by the food product in its normal growth process.
Comparative toxicology refers to comparing the concentration of inherent toxins, those that are naturally occurring and present in the food with the concentration of inherent toxins in the traditional counterpart of the new food.

Inherent substances are a subset of the naturally occurring chemicals that includes all substances except those that are not of biosynthetic origin and that are intentionally introduced into food through human activity. It is through this definition, mycotoxins are naturally occurring, even if they developed through mould growth.

Inherent toxicants are not the only undesirable food constituents. Food contaminants may be naturally occurring or synthetic.

The most important are naturally occurring contaminants in particular those produced by microorganisms. Microorganisms or their toxins occur far more frequently. Two general kinds of microbial toxins are mycotoxins and bacterial food poisoning toxins.



References
http://www.nafex.org/jansonfiles/JansonJuly77.htm
http://extoxnet.orst.edu/faqs/natural/page1.htm http://www.foodstandards.gov.au/_srcfiles/fsc_1_4_1_Contaminants_v78.pdf