Wal-Mart Stores Inc (WMT.N) is focusing on food safety as the world’s largest retailer aims to boost profitability of its more than 400 stores in China, Wal-Mart Asia chief executive Scott Price told Reuters. Food safety is a highly emotive issue in China where there have been numerous scandals from photos of food oil being scooped from drains to tales of phoney eggs and melamine-tainted milk powder.