Around one-fifth of the samples checked at food outlets in North Lincolnshire last year by safety watchdogs were found to be contaminated.
Of the samples, 27 were found to be unsatisfactory, including 12 ready-made prepared dishes.
Three samples were found to contain unsatisfactory levels of Coliforms – a general indication of fecal contamination and three more contained Entero which indicated poor general hygiene at the premises being checked out.
Of 14 samples taken from local takeaways, three were found to be unsatisfactory.
Trevor Laming, assistant director for technical and environment services at North Lincolnshire Council, said: “Examples of poor practices include undercooking, cross contamination, poor cleaning or poor temperature control and time control.
“One sample identified unacceptable levels of Baccilus species which is associated with poorly stored cooked foods and may cause diarrhea and vomiting if bacteria are present in sufficient numbers.”
Mr Laming said the aim was to raise standards rather than increase prosecutions.