Disclosed is a method for manufacturing a tea drink ingredient, comprising: impregnating a tea drink ingredient with an aqueous amino acid solution that contains at least one amino acid selected from the group consisting of leucine, valine and isoleucine, and subjecting the impregnated tea drink ingredient to a heat treatment at a temperature of 100 to 200°C, wherein the tea drink ingredient is selected from the group consisting of tea leaves, barley or brown rice for tea.