PURPOSE: To provide vacuum-lyophilized flowers or petals includable as a dried material for various kinds of foods, excellent in blooming restorability in e.g. its reconstitution with hot water, also giving clear color tone.

CONSTITUTION: Flowers or petals having been stored in salt are desalted by aeration in an aqueous surfactant solution, or, frozen flowers or petals are thawed; the resultant flowers or petals are stacked on a tray for vacuum lyophilization together with clean water or an acidic aqueous solution with its pH value adjusted to ≤5 so as to come to ≥5mm in height followed by carrying out vacuum lyophilization. The vacuum-lyophilized flowers or petals thus obtained are used as a material for various kinds of foods such as fish flour, ready-to-eat 'chazuke', ready-to-eat soup or ready-to-eat 'chirashizushi'.