Characteristics of Pigment Production from Fermentation of Different Varieties of Rice by Monascus purpureus
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
A Monascus purpureus strain with a stable pigment yield was used to examine pigment production in different varieties of rice (namely, japonica, indica, and glutinous), which were used as substrates for shaking flask fermentation. Growth of Monascus was analyzed by measuring biomass, glucose content, and rice composition. In addition, the color characteristics and consumption safety of the produced pigments were evaluated by chromatographic methods such as HPLC and TLC. The results showed that the extracellular color value of Monascus during fermentation of japonica rice was the highest, reaching 19.07 U/mL at 505 nm, which was 2.28 and 2.53 times that of indica and glutinous rice, respectively. The intracellular color value of Monascus was 947.46 U/g (505 nm) in indica rice after 3~4 days of fermentation, which was 1.24 and 1.33 times that of glutinous and japonica, respectively. On the 6~7th day, the intracellular color value of Monascus after fermentation of japonica was higher, reaching 1762.80 U/g at 505 nm, which was 1.41 and 1.86 times that of indica and glutinous rice, respectively. The late-stage fermentation of japonica rice was more conducive to the accumulation of M9 pigments. The yield of six main Monascus pigments was measured by HPLC. It was found that fermentation of indica and glutinous rice significantly promoted the accumulation of two orange pigments, O1 and O2, in the cell, yielding 5.00 and 6.31 times that of japonica rice on the 7th day of fermentation, respectively. Furthermore, fermentation of japonica rice was found to be more conducive to the production of red (R1, R2) and yellow pigments (Y1, Y2). Among the three rice varieties, japonica exhibited the lowest citrinin content during fermentation; therefore, it might be safer to use japonica rice for fermentation and pigment production. In general, when japonica rice was used as the substrate for fermentation, yields of the red and yellow pigments were higher, while higher yields of orange pigment were obtained for glutinous and indica rice.
