Prussic acid in the pits
Many people like to split the bones of apricots, and there are kernels that are pleasant to the taste. However, not everyone knows what danger lies in them, because it contains hydrocyanic acid.
What are the properties of prussic acid? What harm can it cause the body? How to avoid it? We will reveal the answers to these and other questions below. And now about everything in order.
What is hydrocyanic acid
Prussic acid and its compounds (cyanides) is a natural insecticide, that is, a substance that protects plants from pests. They are rich in plant life. They are found in the fruits and even the leaves of many plant species. The hydrocyanic acid itself is externally a colorless liquid with the smell of bitter almond, which can be felt with a small concentration of it. It has a high volatility and low density, is a highly toxic substance.
Prussic acid in the pits is a natural compound. It is in the composition of glycosides, which are low-toxic, while maintaining the integrity and dryness of seeds. As soon as these conditions are violated, chemical reactions occur, leading to the release of hydrocyanic acid, i.e., hydrocyanic acid.
Under the influence of moisture, prussic acid is formed in the pit of cherries, plums, apricots, peaches, mountain ash, sweet cherries, apples, black elderberry, bitter almond kernels. All these plants belong to the Rosaceae family. It is the latter that is characterized by the presence of glycosides capable of releasing hydrocyanic acid.
Separately, it must be said about grapes. It belongs to the family of grapes, but they do not tend to release hydrocyanic acid in the pits. Therefore, grapes in the form of whole berries are used to make wine, which cannot be done with the listed “dangerous” fruits.
The content of hydrocyanic acid in plants
In what quantities in the pits contains prussic acid?
The proportion of amygdalin, from which the toxic substance is released in the purified seeds, is:
- bitter almonds - 2.5–3%;
- apricot - 1–1.8%;
- peach - 2–3%;
- plum - 0.96%;
- cherry - 0.82%;
- sweet cherry - 0.8%;
- apple tree - 0.6%.
Consequently, hydrocyanic acid is least contained in the pits of an apple tree, so the risk of poisoning from these fruits is 4–5 times less than that of bitter almonds.
Deadly and toxic doses
An interesting fact is known: susceptibility to hydrocyanic acid is greater in humans and warm-blooded animals. While cold-blooded animals are less sensitive to its effects - the presence in food of a small amount of cyanide compounds is neutralized naturally without developing poisoning.
There is an opinion that this happens due to chemical reactions with sulfur-containing substances. When ingested from the same pits of prussic acid, hydrocyanic acid is more concentrated than protective mechanisms of neutralization can neutralize, signs of poisoning appear.
According to various sources, a lethal or potentially poisonous dose of poison can be obtained by eating 40 grams of bitter almond, or 100 kernels of apricot kernels, or 50–60 grams of kernels containing amygdalin. In terms of pure prussic acid, contained in the seeds of apples and other fruits, the lowest lethal dose is less than 1 mg / kg.
It is also important to remember that cooking wine on fruits with stones creates a high risk of poisoning. But the jam and compotes - no. If in the latter there is a sufficient amount of sugar, which is the antidote of hydrocyanic acid, there will be no poisoning.
The intoxication of the body from hydrocyanic acid develops when its blood concentration reaches 0.24–0.97 mg / l.
The negative effect of prussic acid on the body
There is a depression of tissue respiration, which is caused in the body by hydrocyanic acid, which is formed in the apricot pits. This process occurs in all tissues and leads to an energy deficit, which is detrimental, above all, to the activity of the central nervous system, and especially to the brain.
The nervous system is more sensitive to the lack of “nutrition,” as a result, the structure of nerve cells changes irreversibly. The development of starvation of nerve cells with normal oxygen content in the blood, which is an important component of tissue respiration and plays a major role in the supply of energy molecules, has been observed. The toxin prevents the inclusion of oxygen in the reaction of their formation, which leads to its accumulation in the blood. This mechanism is associated with a special appearance, dead from poisoning: the scarlet color of the skin and mucous membranes is preserved, which indicates the absence of oxygen starvation.
The action of the poison leads to the stimulation of the release of blood cells from the spleen, which is a consequence of the energy starvation of the brain. According to the results of research, such a reaction occurs due to the direct reflex effect on the spleen. In other words, the body thinks that the energy deficit is caused by a lack of oxygen and, by stimulating the release of its carriers, is trying to solve the problem and restore homeostasis.
At the same time, other vital organs are still able to perform their functions. In those killed by prussic acid produced in the pits of fruits, for example, plums, there are fewer changes in the heart, liver, and kidneys, in contrast to the central nervous system. With the long-term effect of poison in the heart over time, oxygen deficiency also appears due to the inhibition of enzyme systems. Similar changes occur in other organs.
Fabrics lose their ability to consume oxygen. The accumulation of the latter in the blood leads to a decrease in the arteriovenous difference, and then to its disappearance. At the same time, venous blood during severe poisoning will look like arterial.
Hydrocyanic acid refers to weak acids and, at the same time, is a reactogenic substance. In the body there are quite a lot of compounds with which it can react. But since the process of interaction is slow, and pathological changes due to intoxication develop faster, so the toxic substance does not have time to react. The poison actively influences the content of hydrogen ions and leads to a shift in the pH of the medium to the acidic side, and as a result, non-respiratory (metabolic) acidosis develops.
Now it is clear what is so dangerous about hydrocyanic acid and what pathological processes occur during poisoning.
What conclusions can be drawn? You should not eat the kernels of fruits from the Rosaceae family. Jam, compotes, wine should be prepared from the fruit without stones. Or do not spare them sugar. The exception is wine: besides grapes, all other berries must be taken without seeds. Compliance with simple rules will help preserve the health of themselves and their families.