Food Safety Focus (178th Issue, May 2021) – Food Incident Highlight
Bitter Apricot Seeds and Natural Toxins in Food Plants
While bitter apricot seed (北杏) is a common ingredient for preparing Chinese soups, there are concerns overseas due to its significant levels of naturally-occurring cyanide compounds. Excessive consumption of the raw seeds may lead to poisoning.
Some common food plant produce natural toxins as a defence mechanism. Some of them can be safely consumed by removing the toxic parts, such as the seeds of apples, pears, plums, peaches and cherries. Some such as raw green beans can be rendered safe through thorough cooking, likewise soaking and boiling for bamboo shoots, cassava and dried kidney beans. However, flaxseeds and ginkgo seeds contain toxins that cannot be easily reduced to a safe level through usual food preparation methods and therefore should only be consumed in moderation.
As for bitter apricot seeds, thorough cooking in boiling water, such as extended boiling when preparing soups, can significantly reduce the content of cyanide compounds. A study shows that boiling of the bitter apricot seeds for 15 minutes can reduce cyanide contents by 98%.