Abstract: The purpose of the present invention is to provide a water-soluble polysaccharide which is less expensive and enables the production of an acidic protein food or drink, said acidic protein food or drink being stable in an acidic pH range at the isoelectric point of protein or higher, even by using a starting material such as a root vegetable. A water-soluble polysaccharide, which is extracted from a starting material derived from a root vegetable in a wet state with hot water under acidic conditions of pH 2.7-3.7, can well stabilize an acidic protein food or drink in a pH range at the isoelectric point of protein or higher.

Abstract: The purpose of the present invention is to provide a water-soluble polysaccharide which is less expensive and enables the production of an acidic protein food or drink, said acidic protein food or drink being stable in an acidic pH range at the isoelectric point of protein or higher, even by using a starting material such as a root vegetable. A water-soluble polysaccharide, which is extracted from a starting material derived from a root vegetable in a wet state with hot water under acidic conditions of pH 2.7-3.7, can well stabilize an acidic protein food or drink in a pH range at the isoelectric point of protein or higher.

Abstract: The present invention is possible to beautifully color a surface of a gel-like food by providing divalent metal ions or metal ions having a greater valence on the surface of the gel-like food and by applying thereto an aqueous solution containing a pigment, as well as a gelling agent that reacts with the divalent metal ions or the metal ions having a greater valence and causes gelation. To provide the divalent metal ions or the metal ions having a greater valence on the surface of the gel-like food, there are a method in which components that form the divalent metal ions or the metal ions having a greater valence are kneaded into the gel-like food itself and a method in which an aqueous solution containing the divalent metal ions or the metal ions having a greater valence is applied to the surface of the gel-like food.