When Smithfield, the world’s largest pork producer, announced at the end of May that it had agreed to be bought by a Chinese meat processing company, Shuanghui International, it made the US public sit up and take notice.

The $4.7bn (£3.1bn) deal, which still requires regulatory approval, would be the largest takeover of a US business by a Chinese conglomerate, adding to fears among some Americans about the expansionist plans of their biggest economic rival.