In Which Food is Cyanide Found?

January 9, 2026 •

3 min read

According to the World Health Organization, over 2,000 plant species contain naturally occurring cyanogenic glycosides, which can release toxic hydrogen cyanide when processed or ingested improperly. These compounds are found in the edible parts of certain common foods, from tropical roots to fruit seeds, and are a natural defense mechanism for the plant. Understanding in which food is cyanide found is the first step toward safe consumption.

Quick Summary

This guide details the common foods that naturally contain cyanide-releasing compounds and explains the simple, yet essential, steps to detoxify them. It covers staple crops like cassava, seeds of stone fruits, and certain beans, providing crucial safety information for home cooks and consumers.

Key Points

Source of Danger: Cyanide in foods like cassava, apricot kernels, and lima beans comes from natural compounds called cyanogenic glycosides.
Proper Preparation: Peeling, soaking, and thorough cooking are essential steps to neutralize cyanogenic glycosides in foods like cassava and lima beans.
Avoid Raw Kernels: The seeds inside stone fruits such as apricots and cherries are dangerous when raw due to high amygdalin content, and should not be consumed.
Children are More Vulnerable: Cyanide is especially hazardous for children due to their smaller body size, making proper food preparation even more critical.
Cook, Don't Fear: With correct cooking techniques, many foods containing natural cyanide are completely safe and nutritious to eat.
Dietary Diversity: Maintaining a balanced diet and sourcing food from reliable suppliers helps minimize risks associated with natural toxins.

Cyanogenic Glycosides: The Precursors of Cyanide

Cyanide in food is not typically present as a free, toxic compound but rather in a less dangerous form called cyanogenic glycoside. These compounds are stored separately from enzymes in the plant's cell structure. When the plant tissue is damaged through chewing, grating, or improper processing, the enzyme comes into contact with the cyanogenic glycoside, triggering a chemical reaction that releases toxic hydrogen cyanide (HCN). The potential for toxicity depends heavily on the concentration of these compounds and the preparation method used.

Cassava: A Staple Food with a Toxic Twist

Cassava, also known as manioc or yuca, is a staple food for millions, but its roots contain linamarin and lotaustralin, two cyanogenic glycosides. There are two main varieties: sweet and bitter.

Sweet Cassava: Contains lower levels of cyanide (less than 50 mg HCN per kg) and can be made safe by simple peeling and thorough cooking, like boiling or baking.
Bitter Cassava: Has significantly higher concentrations (over 50 mg HCN per kg) and requires more extensive processing, including peeling, grating, prolonged soaking, and fermentation, to leach out the toxins before cooking. Inadequate preparation, often during droughts when alternative food is scarce, is linked to neurological disorders such as Konzo.

Apricot and Other Stone Fruit Kernels

The seeds, or kernels, found inside the pits of stone fruits like apricots, peaches, cherries, and plums contain the cyanogenic glycoside amygdalin. The fruit flesh is completely safe to eat. However, chewing or grinding the kernels releases hydrogen cyanide, which can be poisonous. For adults, consuming just a few small, raw bitter apricot kernels can cause symptoms, and the risk is even higher for children. The baking or cooking process can significantly reduce the toxin level in products made with apricot kernels, but eating them raw is highly discouraged.

Lima Beans: A Common Legume

Raw lima beans, also called butter beans, contain a cyanogenic glycoside called linamarin. When these beans are cooked thoroughly, the enzyme that releases the cyanide is destroyed, rendering them safe for consumption. US-grown varieties have lower levels of linamarin, but prolonged boiling in a large volume of water is the most effective method for removal, especially for varieties with higher concentrations.

Other Foods with Natural Cyanide

Beyond the most common sources, cyanogenic glycosides can be found in a variety of other foods. Many of these are safe when prepared or consumed correctly.

Bamboo Shoots: Fresh bamboo shoots contain taxiphyllin, which can release high levels of cyanide. Boiling the shoots, particularly for 20 minutes or more, substantially reduces the toxin content. Canned bamboo shoots are generally safe as they have already been processed.
Sorghum: This cereal crop can contain cyanogenic glycosides, particularly in young leaves. However, mature sorghum grains are safe to eat, and heat processing used in malting and brewing can destroy the toxins, though some levels may remain.
Flaxseeds: Flaxseeds contain linustatin and neolinustatin, but their low concentration means it is generally safe to consume small amounts. Grinding the seeds may increase bioavailability, but a lethal dose would require consuming a very large quantity.

Comparison of Foods Containing Cyanide


Food Item	Primary Cyanogenic Glycoside	Toxin Location	Safe Preparation Method	Risk Level if Unprepared	Example of Prepared Product
Cassava (Bitter)	Linamarin, Lotaustralin	Roots (all parts)	Peeling, grating, prolonged soaking, boiling	High (Acute poisoning, neurological disorders)	Gari, Tapioca flour
Apricot Kernels	Amygdalin	Seed inside pit	Thorough cooking (e.g., baking)	High (Potentially fatal, especially for children)	Processed almond biscuits
Lima Beans	Linamarin	Raw beans	Soaking, prolonged boiling (>30 mins)	Moderate (Dizziness, nausea, rapid breathing)	Canned lima beans
Bamboo Shoots	Taxiphyllin	Fresh shoots	Boiling (at least 20 mins)	Moderate (Vomiting, diarrhea)	Canned or cooked bamboo shoots

Conclusion

While many common foods naturally contain compounds that can produce cyanide, understanding the source and proper preparation methods is key to safety. Cyanide toxicity from food is primarily a risk associated with improper processing, particularly of staple crops like bitter cassava, or consuming raw kernels from stone fruits. The good news is that traditional cooking methods, including boiling, roasting, and fermenting, are highly effective at neutralizing these cyanogenic glycosides. For most of the foods mentioned, simply ensuring they are cooked thoroughly removes any potential danger. For peace of mind and safety, always source your ingredients from reputable suppliers and follow recommended preparation steps, especially for high-risk foods.

For more detailed information on food safety and natural toxins, consult the Canada.ca website on natural toxins in fresh fruits and vegetables.

Frequently Asked Questions

Yes, apple seeds contain amygdalin, which can release cyanide when chewed or digested. However, the concentration is low, and accidentally swallowing a few seeds is not a cause for concern. Consuming large quantities, especially after crushing them, is what poses a risk.

Yes, cassava is safe to eat if prepared properly. Sweet varieties require peeling and thorough cooking, while bitter varieties need more extensive processing like grating, soaking, and boiling to remove higher concentrations of cyanide.

Apricot kernels contain amygdalin, a cyanogenic glycoside that breaks down into hydrogen cyanide in the body. Raw or unprocessed kernels are unsafe to eat due to the high toxicity risk.

Yes, heat from cooking is effective at breaking down the enzymes that release hydrogen cyanide from cyanogenic glycosides in foods like cassava, bamboo shoots, and lima beans. Boiling, in particular, is an efficient way to reduce the toxin content.

Yes, canned foods such as bamboo shoots or processed tapioca are typically safe. The commercial processing and heating during canning effectively removes the cyanogenic compounds.

Symptoms of acute cyanide poisoning from food ingestion can include rapid breathing, dizziness, headaches, stomach pain, vomiting, and diarrhea. Severe cases can lead to convulsions, loss of consciousness, and potentially death.

Chronic exposure to lower levels of cyanide from consuming poorly processed foods, especially cassava, has been linked to long-term health issues. These can include neurological disorders, thyroid dysfunction, and growth retardation, particularly in regions with malnutrition.