Abstract

Natural pigments are an important alternative to potentially harmful synthetic dyes used as colourant in foods. The toxicity problems caused by those of synthetic colours to the consumers have created a mounting interest towards natural colours. The food bio-colours are gaining importance and have become the focus of attention of many scientists all over the world. The feasibility of wheat bran as a substrate for production of food bio-colour by Monascus purpureus (MTCC 410) strain in SSF was investigated by optimizing the fermentation conditions. The higher yield of red, orange and yellow bio-colours achieved were 126.76, 76.76 and 56.05 OD Units/g dms respectively with wheat bran at optimized process parameters viz. 75% (v/w) initial moisture content, 0.3-0.4 mm particle size, pH 6, incubation at 30°C, inoculation with 3% (spore suspension) of 5 days old culture and an incubation period of 9 days with supplementation as glucose (3% w/w) and peptone (1% w/w) as a carbon and nitrogen source, respectively. The enhanced yield of bio-colours indicated that wheat bran has good potentiality for the production of food bio-colours through SSF.

Keywords: Bio-colours, Monascus, Solid State Fermentation, Wheat bran.