Old Mutual, the UK-based private equity firm, has bought a minority stake in South African food maker In2Food for a price between 200 million and 600 million ZAR ($12 and $36 million), according to a report in Bloomberg. In2Food is a manufacturer of private-label products for grocery chains, founded in Johannesburg in 2007. The firm employs 4,000 people at production plants around South Africa, including one on the outskirts of …