Abstract:
Fermentation conditions for partial yellow,high color value red yeast rice were studied.They include Monascus strains,initial pH and added inorganic salt concentration.Main effects of the culture conditions found included(a)addition of acetic acid in the soaking water to increase the yellow shade,(b)varying salt concentration to change Monascus pigment's color value,(c)0.2% compound inorganic salts to double the color value increase with increased yellow shade,(d)prolonging the culture time to intensify the color value,(e)7-10 days fermentation to increase the orange yellow Monascus pigments,and(f)10-13 days fermentation to slightly decrease content of the pigments.By using the orthogonal test and analysis of variance,the optimal conditions for obtaining the desired pigmentation were found to be: application of cultured 116-R strains,composite inorganic salt concentration of 0.2% and medium initial pH 5.8.