Bio-utilization of Soybean Meal for the Production of Food Bio-Colours through Solid State Fermentation

Natural pigments are an important alternative to potentially harmful synthetic dyes used as colourant in food. The feasibility of soybean meal as a substrate for production of food bio-colour by Monascus purpureus (MTCC 410) in solidstate fermentation was investigated to optimize the fermentation conditions. The results showed that the highest yield of red, orange, yellow and total bio-colour were 29.36 Units/g dms at 500 nm, 23.06 Units/g dms at 475 nm, 9.80 OD Units/g dms at 375 nm and 62.22 OD Units/ g dms respectively achieved with soybean meal at optimized process parameters that include 65% (w/v) initial moisture content, 0.3-0.4 mm particle size, temperature 30°C, pH 6, inoculation with 3% spore suspension of 6 days old culture and an incubation period of 9 days. The yield of bio-colours indicated that soybean meal has good potentiality to be used as a substrate for the production of food bio-colours through solid state fermentation.