Antimicrobial Activity of M onascus Pigments Produced in Submerged Fermentation

Antimicrobial activity of natural pigments produced by Monascus ruber CCT 3802 in submerged fermentation were studied. The pigments were screened for antimicrobial activity against three foodborne bacteria: Staphylococcus aureus, Escherichia coli and Salmonella enteritidis. The orange pigment presented antimicrobial activity against S. aureus ATCC 25923 and red pigments against S. aureus ATCC 25923 and E. coli ATCC 25922. S. enteritidis ATCC 13076 was not inhibited for orange and red pigments. The minimum inhibitory concentration values, which were sensitive to the pigments produced by M. ruber, were in the range of 10 to 20 mg/mL. These results suggest a possibility of inhibiting the growths of pathogenic microorganisms during processing and storage of food products. In conclusion, in addition to the use as a functional food ingredient, the Monascus pigments may be selected as an inhibitor to preserve food products where a natural preservative is desired. Practical Applications The results of this study indicate the possibility of using the pigments as natural colorant and food preservatives, and show the potential these sources have to act as antibacterial ingredients for the food and pharmaceutical industry. The observation of bacteriostatic effects has lead to the consideration that besides the tinctorial properties, the pigments of M. ruber have a preservative value.