To provide a storage duration improver for food that inhibits the development and proliferation of microorganisms causing putrefaction and spoilage without damage to the flavor and taste of flour paste, custard cream, and whip cream.

The storable duration improver suitable for flour paste, custard cream, or whip cream contains three components, as active ingredients, a carbonate salt, an organic acid and/or salt thereof, and an amino acid having the antifungal activity. Preferably, the improver additionally contains a diglycerol fatty acid monoester and/or lysozyme, total four to five components.