Red yeast rice (RYRP) has been utilized for coloring food, brewing wine, and preserving meat, which is also used as a folk medicine for centuries. In this study, a water-soluble nonstarch polysaccharide from RYRP was extracted by using ultrasonic-assisted extraction method. By using the Box-Behnken design to optimize the parameters for extracting the RYRP, the maximum extraction yield (3.37 ± 0.78%) was obtained under the optimal extraction conditions as follows: ratio of water to raw material (40 mL/g), extraction temperature (62 °C), extraction time (75 Min), and ultrasonic power (200 W). Moreover, monosaccharide composition analysis showed that RYRP was consisted of mannose, glucosamine, glucose, and galactose with a molar ratio of 0.152:0.015:1:0.149. The molecular weight distribution analysis showed that the average molecular weight of the RYRP fraction was about 3.49 × 103 Da. Furthermore, RYRP exhibited significant antioxidant activities in vitro and the gastrointestinal-protective effect in vivo using gastrointestinal disorders model mice. RYRP could be explored as a potential source in the pharmaceutical and functional food industries.
Keywords: antioxidant activities; gastrointestinal-protective effect; polysaccharide; red yeast rice; structural characterization; ultrasonic-assisted extraction.
© 2019 International Union of Biochemistry and Molecular Biology, Inc.