[Hippocrates_Garden]

I believe the primary difference in freeze drying vs simple dehydration is the cycling of extremely cold to pretty warm results in cell walls rupturing enabling more of the water to be extracted as the relatively fast cycling results of sublimation of the water from freezing to gas, essentially bypassing the liquid stage, and thus remove almost all the water, while leaving anything less volatile behind, and the product looking essentially the same as before the process.