A method of improving the flavor of a food or beverage; a flavor improver for foods or beverages; a seasoning; and a food or beverage improved in flavor. The method is characterized by adding to a food or beverage a product of an amino-carbonyl reaction between a peptide having a molecular weight of 1,000 to 5,000 and a carbonyl compound. The flavor improver contains the amino-carbonyl reaction product as the active ingredient. The seasoning comprises as the active ingredients the amino-carbonyl reaction product and a flavor. The food or beverage is obtained by adding the flavor improver or seasoning.
