The study of indirect determination of biomass in solid-state fermentation of Monascus by the measurement of glucosamine content

Abstract:

[Objective] The objective of this paper was to provide an accurate and rapid determination method for the biomass of Monascus purpureus in solid-state fermentation (SSF). [Methods] The biomass and glucosamine content was measured by physical and chemical methods, then the relation between biomass and glucosamine content under different cultivation time, media and culture methods was investigated and the conversion relation of biomass and glucosamine content was built. Moreover, the PLS model for the relation between near infrared spectra and measured glucosamine content of medium was built. [Results] The rapid method for estimating biomass in SSF was built by measuring glucosamine content with NIR. The root mean square error of cross-validation of calibration set (RMSECV), the prediction correlation coefficient (Rp) and root mean square error of prediction set (RMSEP) of the best model were 0.648 5, 0.993 4 and 0.217 3, respectively. Besides, the accuracy of biomass calculation was enhanced by the conversion correlation. [Conclusion] On the base of the conversion relation of biomass and glucosamine content, the biomass of Monascus purpureus in SSF could be determined more accurately and rapidly by use of NIR method.

Key words:Solid-state fermentation, Monascus, Biomass, Glucosamine, NIR