Study on the Technological Parameters of Producing Monascus Pigment by Solid-state Fermentation of Tea Residue

The technological conditions of producing the Monascus pigment by solid-state fermentation of tea residue were optimized. On the basis of the single factor experiment, with the ammonium sulfate, tea residue and soybean oil as the influencing factors and the total color value of Monascus pigment as the response value, the Box-Behnken central composite design was used to design a mathematical model, in order to optimize the culture conditions for the production of Monascus pigment by solid-state fermentation. The results showed that the factors affecting the production of monascus pigment by solid-state fermentation of tea residue were the ammonium sulfate, soybean oil and tea residue in order. The optimum culture conditions for producing the Monascus pigment by solid-state fermentation of tea residue were the ammonium sulfate (1.66%), tea residue (35.37%), soybean oil (2.4%) and inoculation amount (3%). And the total color value predicted by the model was (1 076.4±30.2)U·g^-1. Then, the repeated verification tests were carried out and the actual total color value was determined to be 1 063 U·g^-1. The relative error between the measured value of total color value and the predicted value of the regression model was 1.26%, indicating that the regression equation fit well with the actual situation.