PROBLEM TO BE SOLVED: To provide a gelling agent by which an easily swallowable, gelled, acidic thick liquid diet exhibiting good bolus formation while having a low pH of 3-4.6, having little adhesive property and suitably eaten by a person with chewing and swallowing difficulty can be prepared, to solve the problems such as rapid gelling at the preparation, heterogeneity formation of texture caused by the increase of the viscosity, and improvement of yield, and to provide the gelled acidic thick liquid diet for the administration through a tube, having good tube fluidity even when used as the food for the person with the chewing and swallowing difficulty.SOLUTION: The gelling agent for the acidic thick liquid diet contains sodium alginate, a calcium salt insoluble/slightly soluble in neutral water, and a chelating agent, wherein the chelating agent of 0.1-2 pts.mass of is used based on 1 pt.mass of the sodium alginate.COPYRIGHT: (C)2010,JPO&INPIT【課題】pHが3~4.6といった低pHを有する酸性濃厚流動食であっても食塊形成性が良く、付着性も小さく、咀嚼・嚥下困難者の喫食に適した飲み込みやすいゲル状酸性濃厚流動食を調製可能なゲル化剤を提供する。また、調製時の急激なゲル化、粘度上昇による食感の不均一化、歩留まり向上などの課題も解決できる。経管投与用の咀嚼・嚥下困難者用食品として使用される場合も、良好なチューブ流動性を有し、チューブへの付着性も少ないゲル状酸性濃厚流動食を提供する。【解決手段】アルギン酸ナトリウム、中性水不溶・難溶カルシウム塩及びキレート剤を含有し、アルギン酸ナトリウム1質量部に対し0.1~2質量部のキレート剤を用いることを特徴とする酸性濃厚流動食用ゲル化剤を用いる。【選択図】なし