Pressure shear assisted extraction of polysaccharide from Auricularia auricula and its biological activities

Abstract

ABSTRACT: In this paper, using to the comprehensive scoring method, pressure shear assisted extraction was used to prepare polysaccharide from Auricularia auricula (PS-AAP)by orthogonal test to optimize the extraction. The highest comprehensive score (90.70) was obtained under 1: 70 g/mL solid-liquid ratio, 110 °C reaction temperature, 60 min reaction time and 1.0 MPa reaction pressure. Compared to AAP by water bath(WB-AAP), PS-AAP led to a higher extraction efficiency and decreased the relative molecular weight. In addition, infrared spectrum(FT-IR) analysis showed that pressure shear assisted did not change the polysaccharide structure. Scanning electron microscope(SEM) showed that PS-AAP was smaller and more broken by pressure shear assisted. Furthermore, the ratio of glucose to mannose in PS-AAP was relatively higher than WB-AAP, which also proved that PS-AAP had certain antioxidant and hypoglycemic activities. Compared with WB-AAP, the inhibition α-glucosidase and α-amylase activity of PS-AAP increased by 11.37% and 24.43% respectively. These results revealed that PS-AAP has the poten- tial value of being a antioxidant and hypoglycemic agent.

Keywords

• Pressure shear assisted extraction
• Auricularia auricula polysaccharide
• Structural characterization
• Biological activities