Patricia Callahan, Jeremy Manier and Delroy Alexander of the Chicago Tribune examined tobacco-lawsuit documents to show that America's largest foodmaker and its biggest cigarette company have pooled expertise in search of more alluring foods and cigarettes since the dawn of their corporate pairing two decades ago. "Documents show Northfield-based Kraft collaborated on flavor issues with some of the same Philip Morris brain researchers who probed what gives cigarettes their kick. None of those scientists was more controversial than Frank Gullotta, a former top Philip Morris researcher whose brain experiments suggested the company knew more than it claimed about cigarettes' addictive nature." The documents reveal Kraft and Philip Morris discussed investing jointly in brain scans to study how the brain processes tastes and smells. Food scientists even helped their tobacco counterparts make experimental cigarettes — working after-hours in a German coffee plant.