The chokecherry (Prunus virginiana) is a common shrub or small tree native to North America. Its dark purple fruits are frequently used for making jams and jellies. However, the plant carries a conditional toxicity that requires careful handling. While the soft pulp of the ripe fruit is safe to consume, other parts contain chemical compounds that can be harmful if ingested. Certain components must be avoided or properly processed before the fruit can be safely eaten.
The Specific Parts That Are Toxic
The danger in the chokecherry plant is concentrated in the pits, leaves, stems, and bark, rather than the fruit’s flesh. These parts contain naturally occurring compounds called cyanogenic glycosides, most notably amygdalin and prunasin. These compounds are a defense mechanism for the plant.
When the pits, leaves, or stems are chewed, crushed, or damaged, the glycosides contact specific enzymes also present in the plant matter. This interaction triggers a chemical reaction that metabolizes the glycosides into hydrogen cyanide (HCN) gas. The amount of this toxin can vary; wilted leaves often contain a higher concentration than fresh foliage, which concerns grazing animals.
The seeds inside the cherry pit are of particular concern because they are relatively easy to crush during consumption or processing. Since the toxic potential is directly linked to the release of hydrogen cyanide, any damage to the seed, bark, or leaf tissue poses a risk. The fruit pulp itself does not contain these compounds in a harmful concentration.
Symptoms of Poisoning
If the toxic parts of the chokecherry are consumed in sufficient quantity, symptoms of poisoning can range from mild discomfort to severe systemic reactions. Hydrogen cyanide interferes with the body’s ability to use oxygen at the cellular level, effectively causing internal suffocation. Initial, milder symptoms may include headache, dizziness, confusion, or anxiety.
As exposure increases, symptoms progress rapidly to include difficulty breathing, a rapid heart rate, and excessive salivation. In cases of significant poisoning, an individual may experience muscle twitching, convulsions, and a sudden drop in blood pressure. Without immediate medical intervention, consuming a large dose of crushed pits or wilted plant material can be fatal. Anyone who suspects poisoning should seek emergency medical attention without delay.
Safe Preparation for Consumption
The primary way to safely consume chokecherries is by separating the toxic elements from the edible fruit pulp and neutralizing any residual toxin. Safe preparation centers on preventing the seeds from being crushed and using heat to mitigate residual compounds. When preparing the fruit, first remove all stems and leaves, as these contain the toxic glycosides.
The fruit is then typically simmered with water, which softens the pulp and allows the juice to be extracted. Gentle simmering for 15 to 30 minutes is a common method. This cooking process helps break down and volatilize trace amounts of hydrogen cyanide that may have leached into the fruit pulp. It is important to avoid vigorous boiling or crushing the fruit with force during this step, as that could inadvertently crack the pits and release more toxic compounds.
After cooking, the mixture must be strained through a sieve, food mill, or cheesecloth to completely separate and discard the solid pits and skins from the juice or pulp. For clear juice or jelly, the straining should be gentle, allowing the liquid to drip without squeezing the bag. Squeezing can force fine particles from crushed pits into the final product. Once the seeds are safely removed, the juice or pulp can be used to make jams, jellies, syrups, or wine.