Effect of 11 commercially available food coloring dyes was tested on referent bacterial strains: Staphylococcus aureus ATCC 25923, Pseudomona aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212. Mueller-Hinton agar was used as media for bacterial growth to which different concentration of food coloring dyes were added. Two different types of food coloring dyes were used, powder and gel. The results indicated that different food dyes have different effect on bacterial growth due to difference in their ingredients, such as sugars, coloring and emulsifiers. Difference in growth, on media containing food coloring dyes, was also noticed between Gram-negative and Gram-positive bacteria.

Keywords : Food Coloring Dyes; Bacteria; Emulsifiers; Sugar; S.Aureus; P.Aeruginosa; E.Coli; E.Faecalis.