Production and characterization of okara dietary fiber produced by fermentation with Monascus anka

Okara dietary fiber was prepared by liquid fermentation with Monascus anka (M. anka). Infrared spectra results indicated that there were more oligosaccharides because of the hydrogen bond cleavage of the polysaccharides in okara Monascus dietary fiber (OMDF). Scanning electron microscopy and X-ray analyses showed that the structures of OMDF were altered as compared to that of the control. The UV-visible spectrum of the M. anka seed broth (MSB) contained three absorption peaks corresponding to red, orange, and yellow pigments, which were present in equal quantities. The concentration of citrinin in MSB and Monascus okara fermentation broth was 0.980 ppm and 0.940 ppm, respectively. After fermentation, the soluble OMDF content in OMDF was 7.7 g/100 g, which was 1.79 times of that in the control. Further, the water holding capacity, oil holding capacity, and swelling capacity of OMDF increased significantly, while the water retaining capacity decreased slightly. Hypothesis: This study was aimed at investigating the effect of liquid fermentation of M. anka on okara. After fermentation, the dietary fiber structure may change and the functional properties may be improved.