[Problem] To provide a powdery miso having improved moisture absorption resistance, a method for producing the powdery miso, and a method for improving the moisture absorption resistance of the powdery miso. An XRD peak intensity ratio at each diffraction angle when a content of a nucleic acid is 500 to 10000 mg / 100 g and a diffraction peak intensity at a diffraction angle 2θ = 31.7 ° ± 0.5 ° is set to 100 is predetermined. Powder miso that satisfies the above conditions and has improved moisture absorption resistance. The powder miso is preferably a freeze-dried powder. A powder comprising: an adding step of adding a nucleic acid to miso so that the content of the nucleic acid becomes 500 to 10000 mg / 100 g； and a drying step of performing a drying treatment on the raw material after the adding step. Manufacturing method of miso. A method for improving the moisture absorption resistance of a powdery miso in which a nucleic acid is added to a miso so that the content of the nucleic acid is 500 to 10000 mg / 100 g, and then dried. [Selection] Fig. 3C【課題】耐吸湿性が向上した粉末味噌、粉末味噌の製造方法、及び、粉末味噌の耐吸湿性向上方法の提供。【解決手段】核酸の含有量が５００～１００００ｍｇ／１００ｇであり、回折角２θ＝３１．７°±０．５°の回折ピーク強度を１００とした場合における各回折角でのＸＲＤピーク強度比が所定の条件を満たす、耐吸湿性が向上した粉末味噌。該粉末味噌は、フリーズドライ粉末であることが好ましい。核酸の含有量が５００～１００００ｍｇ／１００ｇとなるように味噌に核酸を添加する添加工程と、前記添加工程の後の原料に対して乾燥処理を施す乾燥工程と、を含むことを特徴とする粉末味噌の製造方法。核酸の含有量が５００～１００００ｍｇ／１００ｇとなるように味噌に核酸を添加した後、乾燥処理を施す粉末味噌の耐吸湿性向上方法。【選択図】図３Ｃ
