Heinz has confirmed that Warren Buffett’s Berkshire Hathaway and 3G Capital are buying the US food company for $72.50 a share, or $28 billion. Based in New York but backed by wealthy Brazilians, 3G took fast-food chain Burger King private in 2010. Heinz’s global brands include its ketchup, Ore-Ida frozen potatoes, and other food products.