Wal-Mart, as it often does, this week shook up the US grocery sector with its plans to make a swathe of its private-label products healthier. Elsewhere, speculation of changes within the food-ingredients space continued with Cargill named as a potential bidder for Tate & Lyle. And, a year since Kraft Foods succeeded in getting Cadbury's board to back its plans to buy the UK confectioner, the US group faced rumours that management at Green & Black's wanted to buy the organic chocolate business.