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, α,α-trehalose and saccharide derivatives of α,α-trehalose as effective ingredients.