An object of the present invention is to provide a method capable of efficiently suppressing aging of starch in starch-based foods. The present invention provides the following: (A) component: a starch-based raw material containing at least starch having an amylose content of 15% by mass or more, and (B) component: a composition containing cellulose nanofibers； A starch aging inhibitor and a starch-based food additive comprising a product； a method for producing a starch-based food comprising using the composition instead of at least a portion of starch as a raw material of the starch-based food； and the composition A method for modifying starch-based foods, wherein the product is used in place of at least a portion of starch that is a raw material for starch-based foods. [Selection figure] None【課題】本発明は、澱粉系食品の澱粉の老化を効率よく抑制できる方法を提供することを目的とする。【解決手段】本発明は、以下を提供する：（Ａ）成分：アミロース含量１５質量％以上の澱粉を少なくとも含む、澱粉系原料、および（Ｂ）成分：セルロースナノファイバーを含む組成物；前記組成物を含む澱粉老化抑制剤および澱粉系食品用添加剤；前記組成物を澱粉系食品の原料である澱粉の少なくとも一部に代えて用いることを含む、澱粉系食品の製造方法；ならびに、前記組成物を澱粉系食品の原料である澱粉の少なくとも一部に代えて用いる、澱粉系食品の改質方法。【選択図】なし
