Big sugar processors are set to take on major corn refiners including Archer Daniels Midland Co and Cargill Inc [CARG.UL] before a U.S. jury on Wednesday in a billion-dollar lawsuit that could shape how consumers view two bitter foes in the sweetener market. Several sugar refiners including global leader ASR Group sued in 2011, alleging that a corn trade group's ad campaign describing high fructose corn syrup as "corn sugar" and "natural" was false.