Representing the confectionery firm, Anthony Scrivener QC entered the pleas at a 10-minute hearing at Birmingham Magistrates' Court.
It also emerged today that Cadbury is facing a second bout of legal action following the outbreak of salmonella last year, which resulted in 1m chocolate bars being recalled.
Cadbury is being summoned to appear before Herefordshire magistrates on July 24, to answer charges that it breached environmental regulations. The action follows an investigation of almost a year.
Hereford Council's charges add to the woes of the confectionery giant. In April, Birmingham City Council said it would prosecute Cadbury for putting "unsafe" contaminated chocolate on the market between January 19 and March 10 last year.
The firm discovered salmonella in January but did not inform the Food Standards Agency until June, when it recalled more than 1m of its products.
Hereford Council is alleging that Cadbury did not keep a drainage pipe and roof vents in good repair, that it had an insufficient drainage system, and that it failed to properly clean conveyors or storage silos. Each of the six charges carries an unlimited fine and/or two years in prison.
The contamination incident was blamed on a leaking pipe at Cadbury's Marlbrook plant near Leominster in Herefordshire. The Health Protection Agency said that contaminated chocolate bars were the likely cause of a salmonella outbreak affecting 30 people.
Cadbury has said that the bill for dealing with the contamination may reach £30m.The beleaguered company has also announced it is staging a £300m cost-cutting exercise that includes closing factories, a move away from its Mayfair headquarters, and job cuts. Chief executive Todd Stitzer is expected to announce cuts on June 19.