Diethyl pyrocarbonate used as an antimicrobial agent
added in beer, orange juice, and some soft drinks was found
to react with ammonia to form EC in 1971 and then banned
in the United States (34). Urea is the most important EC
precursor in wine and sake (35,36). It is produced from the
arginine metabolism through urea cycle in yeast. Carbamyl
phosphate generated from arginine metabolism reacts rapidly
with ethanol to form EC. In addition, citrulline produced
through arginine deiminase (ADI) pathway by lactic
acid bacteria is another precursor of EC in wine and soy
sauce (37,38). Cyanate is a predominant precursor of EC in
stone-fruit spirits and other spirits (13,39,40). Cyanogenic
glycosides present mostly in the seed of stone-fruits is enzymatically
or thermally degraded to hydrocyanic acid, which