Alpina Foods, one of the anchors of an agri-business development cluster in Batavia, has abruptly closed. South American-backed Alpina, which produced Greek-style yogurt from its plant in the Genesee Valley Agri-Business Park, closed late last week. The plant employed 35 people and just three years ago underwent a $1.1 million expansion. Officials blamed the shutdown on Alpina losing a co-packaging contract. Alpina came to Batavia in 2011, following an aggressive pitch made by the Genesee County…