Freeze drying was the act of freezing and dehydrating food for preservation. Freeze dried food that had been additionally processed into a fine dust was said to be powdered.
In 2259, the Lapithas Market on Parnassus Beta sold freeze dried meats. (SNW: "Hegemony")
Starfleet field rations included freeze-dried peaches and powdered carrots. (DS9: "Sons and Daughters")