Polyamine content of ordinary foodstuffs and various fermented foods.

Soybeans, tea leaves, and mushrooms were conspicuously rich in spermidine, while oranges contained a large amount of putrescine. Among the fermented foods, soy sauces were rich in putrescine and histamine, while Japanese sake contained plenty of agmatine. These polyamines are thought to be produced from amino acids during fermentation with amino acid decarboxylases formed by the micro-organisms.