Chemical Profile of Monascus ruber Strains

Abstract

Chemical profile of Monascus ruber strains has been studied using gas chromatography-mass spectrometry (GC/MS) analysis. The colour intensity of the red pigment and secondary metabolic products of two M. ruber strains (AUMC 4066 and AUMC 5705) cultivated on ten different media were also studied. Metabolic products can be classified into four categories: anticholesterol, anticancer, food colouring, and essential fatty acids necessary for human health. Using GC/MS, the following 88 metabolic products were detected: butyric acid and its derivatives (25 products), other fatty acids and their derivatives (19 products), pyran and its derivatives (22 products) and other metabolites (22 products). Among these, 32 metabolites were specific for AUMC 4066 strain and 34 for AUMC 5705 strain, whereas 22 metabolites were produced by both strains on different tested substrates. Production of some metabolites depended on the substrate used. High number of metabolites was recorded in the red pigment extract obtained by both strains grown on malt broth and malt agar. Also, 42 aroma compounds were recorded (4 alcohols, 2 benzaldehydes, 27 esters, 3 lactones, 1 phenol, 1 terpenoid, 3 thiol compounds and acetate-3-mercapto butyric acid). Thin layer chromatography and GC/MS analyses revealed no mycotoxin citrinin in any media used for the growth of the two M. ruber strains.

Keywords

• Monascus ruber
• GC/MS
• colouring agents
• anticholesterol and anticancer activities
• essential fatty acids and their esters
• aroma compounds