why's root vegetables exposed to frost sweeter?

Question

i know its because of the sugar being convertd from starch but why does it do that and what chemical process take place to cause this?

Answer 1

Well, this answer is about kale and hardy greens, but probably holds true for root vegetables as well:

"When winter temperatures arrive, hardy greens try to protect their leaf tissues from freezing by converting some stored starch into soluble sugars. The presence of the dissolved sugar lowers the temperature at which the plant sap will freeze by several degrees. When the sap or juice in the these plants does freeze, it expands and ruptures cell walls and other structures, often killing the plant. "

So, the plant is attempting to preserve itself with this conversion process. Neat, huh?! Thanks for that new piece of info!

Answer 2

Frost is actually powdered sugar glaze...