Stefan Oberdorster to head up Northern European efforts, the global e-procurement solutions provider for the food industry, announces the appointment of Stefan Oberdorster as Director of Sales for Northern Europe.    Since its establishment in March 2000, has signed over 500 members, with over one third of the leading one hundred U.S. and European food companies on board. The company aims to continue this success in Northern Europe with the opening of the German office.