Abstract: The microwave-assisted extraction of polysaccharides from Tremella fuciformis (TPS) was optimized. The rheological and gelling properties of TPS were studied. Using a combination of single factor and orthogonal array design methods, the optimum extraction conditions were determined as follows: solvent-to-solid ratio 50:1 (mL/g), particle size 120 mesh, microwave power 400 W, and radiation time 2.0 h, which resulted in a yield of polysaccharide of (33.25 ± 0.14)%. Fourier-transform infrared (FTIR) spectroscopy and rheological measurement showed that TPS was a distinctive acidic heteropolysaccharide, and the TPS solution behaved as a pseudoplastic fluid. The dynamic modulus was increased with increasing frequency and the TPS solutions could form a weak gel structure in the high-frequency region. Texture profile analysis (TPA) showed that TPS concentration significantly influenced its gel hardness and springiness. Rheology TPA suggested that TPS had good rheological and gelling properties for application as a partial substitute for colloids in food.

Key words: Tremella fuciformis polysaccharide, microwave-assisted extraction, FTIR spectroscopy, rheology