Apple cores has poison which can kill

do you remember when our mother warned us not eat apple seeds ,the reason of stop to eat that is for good cause because apple cores has poinson which can kill us and it contain cyanogenic glycosides ,which not food for human and can kill us apple is not the only fruit which contain cyanogenic glycosides also peaches ,apricots ,cherry pits and almonds are the cyanogenic glycosides in the seeds and if we eat 20 apple cores that will kill a adult