Effects of Different Blanching Methods on the Quality of Tremella fuciformis and Its Moisture Migration Characteristics

Blanching is a critical step in the processing of Tremella fuciformis (T. fuciformis). The effects of different blanching methods (boiling water blanching (BWB), ultrasonic-low temperature blanching (ULTB), and high-temperature steam (HTS)) on the quality and moisture migration characteristics of T. fuciformis were investigated. The results showed that the T. fuciformis blanched by ULTB (70 °C, 2 min, 40 kHz, 300 W) had the best quality, including a brighter appearance, superior texture, and good sensory features, with a polysaccharide content of 3.90 ± 0.02%. The moisture migration characteristics of T. fuciformis after blanching exhibited four peaks, displayed strong and weak chemically bound water, immobilized water, and free water, whereas ULTB had a weak effect on the freedom of water in T. fuciformis. The study will provide the foundation for the factory processing of T. fuciformis.

An Immunological Polysaccharide from Tremella fuciformis: Essential Role of Acetylation in Immunomodulation

The edible fungus Tremella fuciformis was shown to have a high molecular weight (1.87 × 10³ kDa) bioactive polysaccharide, denoted as TFP-F1. Monosaccharide composition and NMR analysis of the polysaccharide and its derivatives indicated it contained fucose (Fucp), xylose (Xylp), mannose (Manp), and glucuronic acid (GlcAp) in a ratio of 0.9:1.0:3.2:1.2. Using IR, NMR, and GC-MS spectroscopic data, the structure of TFP-F1 was elucidated as {→3)-[β-D-GlcAp-(1→2)]-α-D-Manp-(1→3)-α-D-Manp-(1→3)-[α-L-Fucp-(1→2)-β-D-Xylp-(1→2)]-α-D-Manp-(1→}_n, with partial acetylation of C6-OH in mannoses. Furthermore, at a concentration of 1 μg/mL, TFP-F1 was found to stimulate the secretion of TNF-α and IL-6 in J774A.1 macrophage cells in vitro via interaction with toll-like receptor 4 (TLR4). The removal of O-acetyl groups led to the loss of immunomodulatory activities, demonstrating that O-acetyl groups play an essential role in enhancing the production of pro-inflammatory cytokines.

Purification, structural characterization and immunostimulatory activity of polysaccharides from Umbilicaria esculenta

In this study, an active component UP1-1 was isolated from Chinese Huangshan Umbilicaria esculenta via hot water extraction and purified by anion-exchange and gel-filtration chromatography. UP1-1 mainly composed of galactose, mannose and glucose in a molar ratio of 0.8:1.0:4.6 with an average molecular weight of 281 kDa. Methylation analysis of UP1-1 revealed the major glycosidic bonds comprised 1,6-linked Glcp, 1,4-linked Glcp, t-linked Glcp, 1,3,6-linked Manp, 1,3-linked Galp, t-linked Galp at the ratio of 2.28:0.38:0.32:0.63:0.25:0.29. Structural analysis results revealed that the backbone of UP1-1 consisted of →6)-β-D-Glcp-(1→, →6)-β-D-Manp-(1→, →4)-β-D-Glcp-(1 → residues with side chains of →3)-β-D-Galp-(1→, β-D-Galp-(1 → and β-D-Glcp-(1 → branches located at O-3 position of →6)-β-D-Manp-(1→. Immunostimulatory activity tests showed that UP1-1 could promote the phagocytic activity and NO production of RAW 264.7 cells in a dose-dependent manner. UP1-1 could significantly improve the proliferation effect of RAW 264.7 cells at the concentration of 50 μg/mL. Thus, UP1-1 exerted good immunostimulatory activity, suggesting that UP1-1 has a great potential application in pharmacological industry.