Production and evaluation of physicochemical properties of red pigment from Monascus purpureus MTCC 410

Microbial pigments are secondary metabolites, which are produced during stationary or late log phase by a variety of microorganisms. M. purpureus MTCC 410 produces an extracellular red pigment in solid state fermentation on cooked autoclaved rice and MEA supplemented with ammonium nitrate. Pigment was extracted with ethanol and further quantified by taking OD at 500 nm. Anaerobic condition and low oxygen pressure inhibited Monascus growth as well as pigment production. Monascus pigment extracted from solid-state fermentation was less sensitive to light than from submerged fermentation. Purified red pigment is thermolabile over 70 oC heating and show a colour change from red to blackish when exposed to 100 oC for 15 min. Stability of the pigment at high temperature and low pH can be enhanced by modifying nitrogen source and substrate for culturing M. purpureus MTCC410.