The protein interactions and rheological properties of skim milk heated in the presence of low levels of reducing agent

► Milks were treated with a disulphide bond reducing agent during heating. ► More disulphide-linked whey protein was found in heated milk treated with the reducing agent. ► Less disulphide-linked κ-casein was found in heated milk treated with the reducing agent. ► Heated milks treated with the reducing agent produced markedly firmer acid gels than heated milks without reducing agent.