Zhenhua Liang,Zhenhua Yin,Xiaopeng Liu,Changyang Ma,Jinmei Wang,Yan Zhang,Wenyi Kang
A water-soluble glucomannogalactan was isolated from P . geesteranus fruit bodies by hot water extraction and column chromatography method. The structure, chain conformation and immune effect of PGP-1c (20.9 kDa) were investigated comprehensively based on high purity and neutral sugar content (94.7 ± 0.5%). Confirmed by monosaccharide composition , methylation and NMR analysis, PGP-1c was composed of unsubstituted (1,6- α -Gal and 1,6- α -3- O Me-Gal) and monosubstituted (1,2,6- α -Gal and 1,2,6- α -3- O Me-Gal) galactose units in the backbone through α -(1 → 6) glycosidic bonds and the possible branches that a long-branched chain composed of →3)-Glc-(1 → Man and a few fucoses were connected at the O -2 of galactose with a branching degree of 48%. Through the conformational behavior of the molecular chain, it was observed that PGP-1c might have a long-branched or stacked macromolecular network caused by O -CH 3 groups. Moreover, PGP-1c could promote the secretion of NO and cytokines significantly in a dose-dependent manner, which indicated a good immune-enhancing effect.
Long-term high salt intake exerts a negative impact on human health. The excessive use of sodium substitutes in the food industry can lead to decreased sensory quality of food. γ-Glutamyl peptides with pronounced taste-enhancing effects can offer an alternative approach to salt reduction. However, the content and yield of γ-glutamyl peptides in natural foods are relatively low. Enzyme-catalyzed synthesis of γ-glutamyl peptides provides a feasible solution. In this study, Pleurotus geesteranus was hydrolyzed by Flavourzyme to generate protein hydrolysates. Subsequently, they were modified by Bacillus amyloliquefaciens γ-glutamyl transpeptidase to generate γ-glutamyl peptides. The reaction conditions were optimized and their taste-enhancing effects were evaluated. Their peptide sequences were identified by parallel reaction monitoring with liquid chromatography–tandem mass spectrometry and analyzed using molecular docking. The optimal conditions for generation of γ-glutamyl peptides were a pH of 10.0, an enzyme condition of 1.2 U/g, and a reaction time of 2 h, which can elicit a strong kokumi taste. Notably, it exhibited a remarkable taste-enhancing effect for umami intensity (76.07%) and saltiness intensity (1.23-fold). Several novel γ-glutamyl peptide sequences were found by liquid chromatography–tandem mass spectrometry, whereas the binding to the calcium-sensing receptor was confirmed by molecular docking analysis. Overall, γ-glutamyl peptides from P. geesteranus could significantly enhance the umami and salt tastes, which can serve as promising taste enhancers.
Lingyang Yao,Huan Tian,Zhengyu Bao,Shuyun Xie,Tao Feng,Min Sun,Hui Ma,Lingyun Yao,Qiangjun Lang
In this study, four Se species including selenite [Se (VI)], selenate [Se (VI)], potassium,2-selenocyanatoacetate (PSeCA), and selenium ore powder (SeOP) were used for biofortification of Pleurotus geesteranus to obtain Se-enriched mushroom. Based on their effects on mycelium growth of P. geesteranus Jinxiu, [Se (VI)] in the concentration range of 100–1000 μg/kg and other three Se species in the range of 100–2000 μg/kg were adopted in spawn running and fruiting body growth stage, with their effects on production yield and elements accumulation evaluated. The results revealed that PSeCA treatment (200 μg/kg) had the highest fruiting body production (290.61 g/bag), followed by 2000 μg/kg of SeOP treatment (286.24 g/bag). SeMet revealed to be dominant species detected in mushroom, with [Se (VI)] exhibited the highest biological efficiency among the four Se species, and 2000 μg/kg of PSeCA treatment exhibited the highest Se content (10.25 mg/kg) in terminal phase of fruiting body. The results suggested that high concentration of PSeCA would be more favored for the Se biofortification. Moreover, Se treatment could greatly alter the mineral elements content of fruiting bodies, both synergistic and antagonistic relationships on accumulation of mineral elements were observed for each tested Se species.
危险品化学品经营许可证（带存储）