Abstract:

Objective: To improve the yield of polysaccharide from rice bran. Methods: On the basis of single factor experimental results, the optimal processing conditions of ultrasound-assisted cellulase-critic acid extraction for rice bran polysaccharide were explored by orthogonal experiments through the evaluation of the yield of rice bran polysaccharide. Infrared spectrometry was used to scan and analyze the group types in rice bran polysaccharide according to absorption peaks in the wavelength range of 4000－500 cm-1. Results: The optimal extraction processing conditions were ultrasonic treatment time of 1 h, ultrasonic treatment temperature of 50 ℃, ultrasonic treatment power of 100 W and pH 5.0. The yield of rice bran polysaccharide was up to 6.69% under the optimal extraction processing conditions. Infrared spectroscopy exhibited that the major functional groups in rice bran polysaccharide achieved by combinatorial extraction method were consistent with those in rice bran polysaccharide extracted by hot water. Conclusion: The structure of the polysaccharide can not be damaged by combinatorial treatments of ultrasonic wave, enzymolysis and critic acid.

Key words: rice bran, polysaccharide, cellulase, ultrasonic wave, citric acid, infrared spectroscopy