Natural Toxins in Food Plants

Some Examples of Natural Toxins

Each toxin is followed by a short list of some (not all) possible sources

• Enzyme inhibitors:
  • Cholinesterase inhibitors - in potatoes, tomatoes, and eggplant.
  • Protease inhibitors - in raw soybeans
  • Amylase inhibitors - in wheat flour
  • Tannins - in tea, coffee, and cocoa
• Cyanogenic glycosides - in cassava.
• Goitrogens (glucosinolates) - in Brassica species: cabbage, broccoli, Brussels sprouts, etc.
• Lectin proteins (phytohemagglutinins) - in red kidney beans
• Lathyrogens - in chick peas and vetch
• Pyrrolizidine alkaloids - in crops contaminated with weeds
• Antivitamins:
  Although not toxic per se, the anti-vitamins can cause problems as a result of their interference with the function or absorption of essential nutrients.
  • Anti-thiamin compounds - in mung beans, rice bran, beets, Brussels sprouts
  • Avidin - in raw egg white

References

Prepared Summer 1997 by Bernadene Magnuson, Ph.D.
University of Idaho, Dept. of Food Science and Toxicology - EXTOXNET FAQ Team.