Crabapples are small, tart fruits from trees belonging to the Malus genus, the same family that produces domesticated apples. The fleshy fruit part is safe to eat, but a risk of poisoning exists if you consume other specific parts of the plant. Like many members of the rose family, the crabapple tree contains compounds that can become toxic when processed or digested.
Identifying the Toxic Components
The toxicity associated with the crabapple is not evenly distributed throughout the plant, but is concentrated in specific anatomical structures. The most toxic parts are the seeds, which are located inside the core of the small fruit. These seeds contain the dangerous chemical compound in a form that is stable until damaged.
Beyond the fruit’s seeds, the leaves, stems, and bark of the crabapple tree also contain the harmful substance. This is important for pets or grazing animals that might browse on the foliage. The concentration of the toxic compound in the leaves and stems can increase significantly when the plant material is stressed or wilting. Therefore, fallen branches or partially dried leaves pose a greater risk than fresh greenery.
The fruit’s core, which encases the seeds, should also be avoided, just as with a standard apple. While the flesh of the fruit itself is harmless, the small size of the crabapple makes it easier to accidentally consume the core and seeds together. For human consumption, any part of the fruit other than the flesh should be discarded before preparation.
The Specific Chemical Threat
The toxic potential of crabapples stems from the presence of amygdalin, a natural compound. Amygdalin is a cyanogenic glycoside, a plant metabolite found in the seeds of many fruits in the rose family, including cherries, apricots, and plums. This compound acts as a chemical defense mechanism against herbivores.
Amydgalin is relatively inert until it is metabolized. When the seeds, stems, or leaves are chewed or crushed, the plant cells are damaged, allowing enzymes to contact the amygdalin. This enzymatic reaction breaks the glycoside down, ultimately releasing hydrogen cyanide (HCN), a rapid-acting poison.
Hydrogen cyanide interferes with the body’s ability to use oxygen at the cellular level. The resulting condition is a form of cellular asphyxiation, where cells cannot produce the energy needed to function. The amount of cyanide released from a few accidentally swallowed seeds is typically minimal and causes no effect. However, ingesting a large quantity of chewed seeds can lead to serious poisoning.
Safe Consumption and Identifying Symptoms
The consumption of crabapples is generally safe provided the toxic parts are removed before eating. Cooking is the most common way to prepare crabapples, as their natural tartness makes them unpalatable when raw. Preparation for jellies, sauces, or cider involves removing the core, seeds, and stems, which eliminates the source of the cyanogenic glycosides.
If a person has consumed a large number of chewed seeds or other plant parts, symptoms of cyanide exposure can appear quickly. Mild signs of poisoning include headache, dizziness, and a feeling of confusion. As exposure becomes more significant, symptoms can escalate to include vomiting, rapid breathing, and difficulty coordinating movements. Severe cases may involve convulsions, shallow breathing, and hypoxia, requiring immediate emergency medical attention.
Crabapples also pose a risk to household pets and livestock, who may not be selective about which parts of the fruit they eat. Dogs and cats can be affected by eating fallen fruit, especially if they chew the seeds or consume large amounts of leaves and stems. Symptoms in pets are similar to those in humans, including vomiting, excessive panting, dilated pupils, and signs of shock.
Grazing animals like horses and sheep are particularly susceptible because they might ingest a large volume of fallen leaves and fruit while foraging. If a pet or livestock animal shows distress after consuming crabapples, contacting a veterinarian or a pet poison control center immediately is the recommended course of action. Preventative measures, such as regularly clearing fallen fruit and leaves from the ground, can reduce the risk of accidental poisoning.