breeding have reduced their toxin contents to the point that they’re not generally hazardous, unusual preparations or serving sizes can cause problems The following plant toxins are worth being aware of Alkaloids Alkaloids are bitter-tasting toxins that appeared in plants about the time that mammals evolved, and seem especially effective at deterring our branch of the animal family by both taste and aftereffects Almost all known alkaloids are poisonous at high doses, and most alter animal metabolism at lower doses: hence the attractions of caffeine and nicotine Among familiar foods, only the potato accumulates potentially troublesome alkaloid levels, which make greened potatoes and potato sprouts bitter and toxic (p 302) Cyanogens Cyanogens are molecules that warn and poison animals with bitter hydrogen cyanide, a deadly poison of the enzymes that animals use to generate energy When the plant’s tissue is damaged by chewing, the cyanogens are mixed with the plant enzyme that breaks them apart and releases hydrogen cyanide (HCN) Cyanogen-rich foods, including manioc, bamboo shoots, and tropical varieties of lima beans, are made safe for consumption by open boiling, leaching in water, and fermentation The seeds of citrus, stone, and pome fruits generate cyanide, and stone-fruit seeds are prized because their cyanogens also produce benzaldehyde, the characteristic odor of almond extract (p 506) Hydrazines Hydrazines are nitrogencontaining substances that are found in relatively large amounts (500 parts per million) in the common white mushroom and other mushroom varieties, and that persist after cooking Mushroom hydrazines cause liver damage and cancer when fed to laboratory mice, but have no effect in rats It’s not yet clear whether they pose a significant ... tropical varieties of lima beans, are made safe for consumption by open boiling, leaching in water, and fermentation The seeds of citrus, stone, and pome fruits generate cyanide, and stone-fruit seeds are prized because their cyanogens... benzaldehyde, the characteristic odor of almond extract (p 506) Hydrazines Hydrazines are nitrogencontaining substances that are found in relatively large amounts (5 00 parts per million) in the common white mushroom and. .. chewing, the cyanogens are mixed with the plant enzyme that breaks them apart and releases hydrogen cyanide (HCN) Cyanogen-rich foods, including manioc, bamboo shoots, and tropical varieties of lima beans, are made safe