3.2. Storage test of Gouda cheese
E. coli is known as a faecal contaminant of all kinds of foods, but a contamination could also be affected by the raw milk [9]. Therefore this germ was chosen for the storage test of cheese. To study the effect of the developed antimicrobial packaging film, Gouda cheese was inoculated with 1.8 x 10³ cfu/cm² of E. coli DSM 498. While on the reference samples, covered with a lacquered polyethylene-film without sorbic acid, the viable count of E. coli stayed nearly the same during the storage time of four weeks, the viable E. coli-count on the cheese slices covered with the active film was reduced by approx. one log cycle to one tenth of the initial count (Fig. 2). In summary a positive effect of the antimicrobial film on the microbiological safety of cheese after contamination could be demonstrated.