Naturally Occurring Toxins in Foods

Plants have developed more than 10,000 natural compounds that protect them against threats to their existence. A plant’s natural toxins are intended to guard against specific threats by predators or disease, such as hungry insects or damaging fungus.

Some of these toxins produced naturally by plants could cause illness in humans if they were concentrated at high levels and were consumed in large quantities. For example, potato plants contain the chemical solanine.

Potatoes that are freshly dug up and are “sunburned” contain seven times the levels of solanine than normal potatoes that are not sunburned. Solanine cannot be washed away or destroyed during cooking. It has a bitter taste and can cause a burning sensation in the throat. Illness and death have resulted when individuals consumed green potatoes and potato shoots. However, solanine is an excellent pesticide. It provides protection from common potato pests.

Another example of a natural toxicant is a poison called aflatoxin. It is produced by a mold that grows on grains, corn, peanuts and other nuts. If ingested in large amounts it is a potent liver toxin; it has been shown to be a liver carcinogen. Most American food processors have established rigorous programs to monitor the presence of aflatoxin. The FDA has set a maximum permissible level for aflatoxin at 20 parts per billion.

Safe food solutions to naturally occurring toxins in foods:

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