A bioactive Pleurotus eryngii aqueous extract powder (SPAE) was obtained by spray drying and its performance in terms of physicochemical properties, in vitro digestion, inflammatory factors, and modulation of the intestinal microbiota was explored. The results indicated that the SPAE exhibited a more uniform particle size distribution than P. eryngii polysaccharide (PEP). Meanwhile, a typical absorption peak observed at 843 cm⁻¹ in the SPAE FTIR spectra indicated the existence of α-glycosidic bonds. SPAE exhibited higher antioxidant abilities and superior resistance to digestion in vitro. In addition, SPAE supplementation to mice significantly reduced the release of factors that promote inflammation, enhanced the secretion of anti-inflammatory factors, and sustained maximum production of short-chain fatty acids (SCFAs). Additionally, it significantly enhanced the relative abundance of SCFAs-producing Akkermansia and reduced the abundance of Ruminococcus and Clostridiides in intestines of mice. These results show the potential of SPAE as a novel material with prebiotic effects for the food and pharmaceutical industries.

Tremella fuciformis Berk., also known as white fungus and snow fungus, is one of the important edible and medicinal mushrooms in China. The quality characteristics and metabolites of different T. fuciformis varieties directly affect the stability of their processed products. In this study, two new varieties of Tremella fuciformis, namely ’TYH-SD1’ (yellow) and ’TWH-SD2’ (white), which were obtained by the team through single-spore crossbreeding and its control varieties Tr21 (yellow) and Tr01 (white), were used as test materials. The characteristics and nutritional quality of the four varieties of substrates were comparatively analyzed, while metabolomics was employed to investigate the differences in flavor substances. The results demonstrate that TYH-SD1 and TWH-SD2 had a higher rehydration rate and faster rehydration speed compared with the control strains Tr21 and Tr01, with a smaller stem and higher yield. Notably, TWH-SD2 had a 29.06% increase in its rehydration rate and it had higher contents of crude polysaccharide and vitamin D₃. The surface of TYH-SD1 ear pieces exhibited a porous structure with a larger pore size and the surface of TWH-SD2 ear pieces displayed a surface characterized by connected gully-like protrusions and fewer indentations, which were significantly different from that of Tr21 and Tr01 ear pieces. The textural analysis shows that TYH-SD1 and TWH-SD2 ear pieces were softer and more elastic, with greater cohesion and recovery, indicating that they had high tensile and deformation recovery ability. Metabolomics analysis revealed that the relative content of aldehydes in the volatile flavor substances TYH-SD1 and TWH-SD2 was high in n-alpha-aldehyde, nonanaldehyde, and n-pentanal. The relative content of alkanes in TYH-SD1 was second only to that of aldehydes, with decane having the highest content, contributing to its more almond aroma, fruity aroma, and fat aroma. TWH-SD2 exhibited the highest concentration of alcohols, accounting for 43.57%, which may result in a clear, mushroom, and lipid odor. The above results will provide theoretical basis for the further production, processing, and application of the new varieties.

Cultivation substrate critically affects the quality of Tremella fuciformis. Five substrates, including cottonseed hulls (MZKs), Machilus pauhoi Kanehira sawdust (BNM), lotus seed hulls (LZKs), Corethrodendron scoparium sawdust (HB), and palm fiber (ZL), were evaluated for their effects on agronomic traits, nutritional composition, texture, and taste characteristics. Untargeted metabolomics was applied to elucidate substrate-associated metabolic variations, and polysaccharide monosaccharide composition was quantitatively analyzed. The results showed that the BNM group exhibited the highest fresh weight, whereas the LZK group presented the highest dry weight and crude polysaccharide content. The ZL group displayed the greatest ear piece thickness and fruiting body elevation. Higher protein contents were observed in the ZL and LZK groups, with no differences in crude fiber content. Texture analysis indicated that hardness was highest in the LZK group, whereas the MZK group showed better springiness, cohesiveness, and chewiness. Regarding taste characteristics, the MZK group exhibited the strongest sweetness, the LZK group showed a markedly higher bitterness, and umami levels were comparable across all groups. Metabolomic analysis revealed that substrate-induced variations in amino acids, saccharides, and taste-related metabolites were significantly associated with nutritional quality and taste attributes of T. fuciformis. Polysaccharides of fruiting bodies cultivated on the five substrates consisted of six monosaccharides, with composition ratios similar to those of spore extracellular polysaccharides; among them, differences in glucuronic acid (GlcA) proportion represented a key indicator distinguishing fruiting body polysaccharides from spore polysaccharides. This study revealed the metabolic basis and polysaccharide composition underlying substrate-dependent quality of T. fuciformis, supporting substrate optimization for high-quality production.