Medium Optimization for Production of Monascus purpureus Pigment through Solid-state Fermentation

Abstract

Colorants are component that is commonly added to many kinds of product, including food products. Regardless of its effectiveness and lower price, the effects of synthetic colorants towards human’s health become a challenge for food colorant industries. Production of natural food colorant using microorganism as the producing agent is a promising prospect because microorganism has a high growth rate. Monascus purpureus can produce a set of natural pigments consist of yellow (monascin and ankaflavin), orange (rubropunctatin and monascorubrin) and red (rubropunctamine and monascorubramine) pigment. The objective of this research is to optimize the micronutrient composition in the medium for the production of Monascus pigment through solid-state fermentation using the job’s tears (Coix lacryma-jobi L) as the substrate. Response surface method (RSM) was used to optimize the concentration of four substrate components: MSG, NaCl, KH2PO4, and MgSO4. From the experiment, it was found that the maximum red pigment was produced in medium with additional of (w/w): MSG 1.496%, NaCl 1.0%, KH2PO4 3.515% and MgSO4 0.206%. The yellow pigment was maximally produced in medium with additional of (w/w): MSG 1.5%, NaCl 1.0%, KH2PO4 2% and MgSO4 0.2%. Biomass was maximally produced in the medium with additional of (w/w): MSG 1.41%, NaCl 1.01%, KH2PO4 5.0% and MgSO4 0.2%. Among those nutrients, MSG gave the biggest impact on the increasing of pigment and biomass production.