SHIJIAZHUANG, China (AP) — China’s food safety crisis widened Friday after the industrial chemical melamine was found in milk produced by three of the country’s leading dairy companies — prompting stores, including Starbucks, to yank milk from their shelves. The recalls come as evidence is mounting that adding chemicals to watered-down milk was a widespread practice in China’s dairy industry. Sipping from a carton of milk at a news conference, the chief financial officer of one of the companies, Mengniu, apologized for the tainted milk. But he insisted only a small portion of the company’s inventory had been contaminated and said the tainted milk came from small-scale dairy farmers.