Abstract: A glycolic acid salt that can be a raw material (intermediate product) for producing glycolic acid is more efficiently produced by a simple process. A method for producing a glycolic acid salt includes step (1) of reacting at least one compound selected from the group consisting of glycolonitrile and glycolamide with water in the presence of a metal oxide containing 50% by mass or more of at least one element selected from the group consisting of a rare earth element, a group 4 element of the periodic table, and a group 12 element of the periodic table, and a base to obtain a glycolic acid salt.

Abstract: An object of the invention is to provide a simple method for producing methionine and/or 2-hydroxy-4-(methylthio)butanoic acid at a high yield using 3-(methylthio)propionaldehyde as a raw material. An oxide catalyst containing cerium, 3-(methylthio)propionaldehyde, a compound containing cyanide ion, ammonia or a compound containing ammonium ion, and water are contacted with each other to produce methionine and/or 2-hydroxy-4-(methylthio)butanoic acid.

Abstract: An object of the invention is to provide a simple method for producing methionine and/or 2-hydroxy-4-(methylthio)butanoic acid at a high yield using 3-(methylthio)propionaldehyde as a raw material. An oxide catalyst containing cerium, 3-(methylthio)propionaldehyde, a compound containing cyanide ion, ammonia or a compound containing ammonium ion, and water are contacted with each other to produce methionine and/or 2-hydroxy-4-(methylthio)butanoic acid.