Maltodextrin is not sweet, its very very bland, and it contains no sugar.Sweetening your stuff with Maltodextrin is like saying , I use flour to sweeten things you eat.Because Maltdextrin is about as bland as flour.
As far as Carbs go, use Waxey Maize Starch, its so much better then Maltodextrin.If you cant afford Waxey Maize Starch, you can use Frodex, which is preet dam good carb