It is no exaggeration to say that without the Maillard reaction the world would be a much less delicious place: it is the Maillard reaction that is responsible for the flavor of bread crust, roasted vegetables, and many other roasted, savory flavors. In this case, the Maillard reaction is responsible for the nutty, meaty flavors of chocolate, while also reducing some of the astringency and bitterness.