The present invention provides a novel means for stabilizing methionine chloride in a composition. The composition of the present invention contains the following components (A) methionine chloride； and (B) one or more substances selected from the group consisting of Magnolia Bark and extracts thereof. The component (B) has the function for suppressing the content reduction of methionine chloride and thus achieving its stabilization. The composition may further contain: (C) one or more substances selected from the group consisting of Perilla Herb and extracts thereof and (D) starch.本發明係提供將組成物中的氯化甲硫胺基酸安定化之新穎手段。本發明的組成物，係含有以下之成分(A)及(B)：(A)氯化甲硫胺基酸；(B)從厚朴及其萃取物所構成群組中選擇之1種以上。
