Hospital food will suffer as a result of the plan to outsource purchasing to US group Novation, according to NHS caterers.
They fear that the £3.7b deal, which is expected to be announced some time in the next three months, will see food quality suffer as prices are driven down.
John Hughes, catering manager at Nottingham City Hospital, said: "Novation will earn its money from the savings it makes. Aspirations for purchasing quality food might as well be put in the bin, together with Loyd Grossman and the Better Hospital Food programme."
Hospital Caterers Association chairman Alison McCree said she was "extremely disappointed" at the move and concerned that Novation was under investigation in the USA for taking bribes.
An NHS spokesman said that the allegations would have no bearing on the awarding of the contract.
He added that individual trusts could opt out of any purchasing deal if it were cost-effective to do so.