JAB Holding Company has acquired the American brands Peet’s Coffee, Caribou Coffee and Keurig Green Mountain, all since 2012. It also combined the European coffee giant D.E. Master Blenders 1753 with the coffee business of Mondelez to create a company now known as Jacobs Douwe Egbert. Then it bought the high-end coffee retailers Stumptown Coffee Roasters and Intelligentsia. Mondelez continues to own 25 percent of Douwe Egbert and has a similar stake in Keurig. JAB, which is privately held, said it would add the Panera restaurant chain to its growing empire of American coffee and food favorites for $7.5 billion, including debt. It is only the latest effort to expand into restaurants by JAB, the investment arm of the Reimann family of Germany, who are heirs to the consumer goods company Joh. A. Benckiser. In 2014, JAB bought the bagel chain Einstein Brothers, which it has been combining with Caribou is some markets. And last year, it paid $1.35 billion for Krispy Kreme, the struggling doughnut chain. In Panera, JAB will acquire a popular fast casual chain that serves soups, salads, sandwiches and baked goods at about 2,000 locations.