Abstract: In this study,four different methods were used to extract polysaccharides from Tremella aurantialba fruiting bodies,which included hot water extraction (H-TAP),ultrasonic-assisted extraction (U-TAP),enzyme-assisted extraction (E-TAP) and microwave-assisted extraction (M-TAP).Their chemical compositions and yields were determined and compared by using high-performance anion-exchange pulsed-amperometric detection chromatography (HPAEC-PAD) and fourier transform infrared spectrophotometer (FT-IR).In vitro antioxidant activities were also studied on the basis of hydroxyl radical-scavenging activity.The results showed that the cellulase-assisted extraction (E-TAP) was the most optimal method in terms of their yields and hydroxyl radical-scavenging rates.Single-factor tests and orthogonal experimental design (L₉(3⁴)) were used to obtain the optimal extraction conditions.Results showed that the optimal parameters were as follows∶ultrasonic time,50 min;enzyme temperature,55 ℃;water to raw material ratio,80 mL/g;pH,4.5.Under the optimal extraction conditions,the highest extraction yield of polysaccharide TAP was 22.68%.

Key words: Tremella aurantialba polysaccharide, extraction, cellulase, hydroxyl radical, orthogonal test design