Dean Foods, the largest milk processor in the US, filed for bankruptcy this week after posting significant financial losses during the past year. The company has unsecured debts of $850m (€770m) and said it is in talks with Dairy Farmers of America regarding a potential asset sale.Based in Dallas, Texas, Dean Foods has endured a very difficult year after losing a supply deal with its biggest customer, Walmart, in 2018. Walmart, the largest supermarket chain in the US, ended its liquid milk contract with Dean Foods in 2018 after it opened its own milk plant in the state of Indiana. According to Dean, the liquid milk contract with Walmart accounted for almost 475m litres every year.