Faculty of Food Technology and Biotechnology, University of Zagreb
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.Svrha je rada bila proučiti kemijski sastav sojeva plijesni Monascus ruber pomoću plinske kromatografije i masene spektrometrije. Ispitan je i intenzitet crvenog pigmenta te sekundarni produkti metabolizma dvaju sojeva plijesni M. ruber (AUMC 4066 i AUMC 5705) uzgojenih na deset različitih podloga. Produkti metabolizma mogu se razvrstati u 4 skupine: spojevi koji snižavaju razinu kolesterola, antikancerogeni spojevi, prehrambene boje i esencijalne masne kiseline neophodne za ljudsko zdravlje. Plinskom je kromatografijom i masenom spektrometrijom pronađeno 88 produkata metabolizma, a među njima maslačna kiselina i njezini derivati (25), ostale masne kiseline i njihovi derivati (19), piran i njegovi derivati (22), te ostali metaboliti (22). Od ukupnog broja produkata, njih 33 je specifično za soj AUMC 4066, a 34 za soj AUMC 5705, dok su oba soja proizvela 22 produkta na različitim podlogama. Proizvodnja je produkata ovisila o upotrijebljenoj podlozi. Velik je broj metabolita pronađen u ekstraktima crvenog pigmenta iz oba soja uzgojena na podlogama od slada. Pronađena su 42 aromatska spoja, i to 4 alkohola, 27 estera, 3 laktona, 1 fenol, 1 terpenoid, 3 tiola i 1 merkapto spoj. Tankoslojnom i plinskom kromatografijom te masenom spektrometrijom nije pronađen mikotoksin citrinin ni u jednoj podlozi na kojoj su rasla ova dva soja plijesni M. ruber
