The present invention has objects to provide a method of inhibiting the 2,3-butanedione formation in order to produce a satisfactorily flavorful processed cacao bean product and an agent for inhibiting the 2,3-butanedione formation which is used for the method, and solves the above objects by providing a method of inhibiting the 2,3-butanedione formation during the process and/or preservation, and an agent for inhibiting the 2,3-butanedione formation which comprises one or more members selected from the group consisting of maltitol, .alpha.,.alpha.-trehalose and saccharide derivatives of .alpha.,.alpha.-trehalose as effective ingredients.