Inhibitory effects of fruit flavors on methane production during anaerobic digestion

► Fruit flavors belonging to terpenoid, aldehyde, and alcohol were inhibitors to anaerobic digestion. ► Terpenoid could reduce methane production 95% at concentration of 0.5%. ► Aldehydes decreased methane production up to more than 99% at concentration of 0.5%. ► Alcohol reduced methane production 99% at concentration of 0.5%. ► Myrcene required lowest concentration to reduce 50% methane production among the tested flavors.