Maltodextrin is a (mostly) non-fermentable sugar used to enhance body, mouthfeel, and head retention. These changes can affect the perceived taste of beer, but it does not contribute any significant sweetness. They are flavourless, colourless, and non-caloric. It does not contribute any significant sweetness to a beer.
Typical usage is between 125-257 g per 22L. For best results, add during the hot side process – ideally to the kettle, or at least prior to cooling.