Liuxi Xia,Yuxiang Bai,Wanmeng Mu,Jinpeng Wang,Xueming Xu,Zhengyu Jin
Instead of β-cyclodextrin (β-CD), branched β-CDs have been increasingly used in many aspects as they possess better solubility and higher bioadaptability. But most commercialized branched β-CDs were chemically synthesized. Thus, the glucosyl-β-cyclodextrin (G1-β-CD) prepared via enzymatic approach could be a nice substitute. However, the yield of G1-β-CD was low. Here, we reported a controlled two-step reaction to efficiently prepare G1-β-CD from maltodextrins by β-cyclodextrin glucosyltransferase (β-CGTase) and amyloglucosidase (AG). Compared to the single β-CGTase reaction, controlled two-step reaction caused a yield increase of G1-β-CD by 130%. Additionally, the percentage of G1-β-CD was enhanced from 2.4% to 24.0% and the side products α-CD and γ-CD were hydrolyzed because of the coupling activity of β-CGTase. Thus, this controlled two-step reaction might be an efficient approach for industrial production of pure G1-β-CD.
Constructing a stable interfacial adhesion morphology of polymer blends remains an ongoing challenge in terms of the intrinsic instability of phase morphology. Herein, we obtained poly(ethylene 2,5-furandicarboxylate)/poly(glycolic acid) (PEF/PGA) blends with stable interface adhesion morphology and excellent physical properties by a two-step reactive blending method with the assistance of 2,2-bis(hydroxymethyl)-2,2,2-nitrilotriethanol (BIS-TRIS) and reactive elastomer (EGMA). Due to the formation of bonding points and branched/cross-linked structures, the interfacial morphology and melt strength of blends are significantly improved, leading to obviously enhanced foaming properties, thermostability, and mechanical properties. Specifically, when EGMA content was less than 20%, the blends still maintained tensile strength similar to that of neat PEF but with excellent toughness. Furthermore, all blend foams possess thin-walled cells with relatively uniform morphology, and the expansion ratio is more than 10-fold and shows greater compressive strength than commercial PET foams. Moreover, when the PEGMA foam was immersed in water for 2 weeks, the compression strength of the foam decreased by more than 70%, which makes it potentially useful in the field of temporary support.
This study develops a catalytic system using pyruvic acid (PYA) and Fe2+ to efficiently coproduce xylo-oligosaccharides (XOS) and (manno-oligosaccharides) MOS from food material (Gleditsia sinensis Lam. fruit.) and its waste peel, respectively. The system achieved maximum yields of 67.12% XOS and 57.32% MOS without toxic byproducts such as furfural and 5-hydroxymethylfurfural (5-HMF) below 130 °C. The process employs a two-stage mechanism, where PYA cleaves galactose side chains and xylan backbones, while Fe2+ stabilizes β-1,4-glycosidic bonds, resulting in polymerization degree ratios of X2–3/X4–5 at 0.975 and M2–3/M4–5 at 0.96. The composite oligosaccharides, PFMX, showed significant prebiotic effects, enhancing Bifidobacterium adolescentis growth to 3.4 × 108 CFU/mL─144% higher than commercial fructooligosaccharides (FOS). The concentration of short-chain fatty acids (SCFAs) was 15.09 g/L, with specific products propionic acid (1.44 g/L) and butyric acid (0.15 g/L). PFMX effectively regulates substrate utilization and SCFA metabolism, offering a promising strategy for developing functional foods that target gut inflammation.
危险品化学品经营许可证（带存储）