Effects of water-soluble soybean polysaccharide on rheological properties,stability and lipid digestibility of oil-in-water emulsion during in vitro gastrointestinal digestion

Water-soluble soybean polysaccharide (SSPS) is a naturally occurring emulsifier. SSPS was used as the sole emulsifier to stabilize an oil-in-water (O/W) emulsion. The effects were investigated of different SSPS concentrations (3–20% (w/w)) on the lipid digestibility, rheological properties and stability of O/W emulsions during in vitro digestion model. The droplet size of the emulsions tended to increase during the oral phase because the emulsions were unstable and droplets coalesced, except with a SSPS concentration of 20% (w/w). The presence of SSPS markedly reduced the free fatty acid (FFA) content after its stabilized O/W emulsion passed through in vitro gastrointestinal digestion. The amount of FFA significantly decreased as the concentration of SSPS increased due to SSPS stabilization film on oil droplet surface and high viscous system. SSPS may be an attractive alternative ingredient to control the lipid digestibility of emulsions for various food products.     

金针菇多糖对微冻大黄鱼及其鱼片品质变化的影响

为研究金针菇多糖（polysaccharide from Flammulina velutipes，FVP）对微冻大黄鱼及鱼片在贮藏期间肌原纤维蛋白性质的变化及水分分布的影响，实验分别选用0.03、0.06、0.09 g/L FVP浸渍处理大黄鱼和鱼片，以无菌水处理为对照组，分析微冻贮藏期间样品的感官指标得分、总挥发性盐基氮含量、总巯基含量、Ca2＋-ATPase活性、蛋白流变学性质以及水分迁移变化规律。结果表明：FVP可有效抑制整鱼总挥发性盐基氮含量上升和感官得分的下降；减缓整鱼及鱼片在微冻过程中总巯基含量、Ca2＋-ATPase活性下降和水分流失；此外FVP还能够延缓大黄鱼因腐败而出现的蛋白凝胶能力减弱。在本实验选取的多糖浓度范围内，0.09 g/L FVP处理组保鲜效果较强。该研究结果可为FVP用于水产品贮运保鲜提供理论参考。     

泥鳅多糖的研究进展

近年来随着泥鳅养殖及产业化的快速发展, 泥鳅资源的开发和高值化利用已成为研究热点。泥鳅是一种含有丰富优质蛋白、脂肪酸以及微量元素的营养健康食品, 具备多种保健功能和药用价值, 其中泥鳅多糖是从泥鳅中提取得到的一种游离中性多糖, 具有耐缺氧、抗肿瘤、抗氧化、调节免疫、降血糖、抗炎等功能。本文主要综述了泥鳅多糖的制备方法、分离提纯方法、结构表征、生物活性、精深加工等方面的研究进展,旨在为泥鳅多糖的高值化利用提供一些理论基础, 为泥鳅产业链的快速发展提供新的发展方向。     

Health-promoting effects of dietary polysaccharide extracted from Dendrobium aphyllum on mice colon,including microbiota and immune modulation

The health-promoting effects of a polysaccharide (DAP) purified from Dendrobium aphyllum, on mice colon were investigated. The results indicated that consumption of DAP facilitated the differentiation degree of CD4⁺ T cells to Th₁, Th₁₇ and Treg cells; and depressed the differentiation degree to Th₂ cells, since DAP up-regulated IL-6 expression (from 1.08 ± 0.24 to 3.40 ± 0.36). Besides, oral administration of DAP reduced the gastrointestinal transit time from 255 ± 1.21 to 164 ± 0.46 min, decreased the pH from 6.70 ± 0.27 to 5.54 ± 0.31, improved faecal water-binding capability from 59.4% ± 0.35 to 63.5% ± 0.22. Additionally, the increase in four health-promoting short chain fatty acids were observed, which might result from the enrichment of the relative abundance of health-promoting microbiota genera, including Porphyromonadaceae and Ruminococcaceae. The DAP-induced up-regulation of the genus Erysipelotrichaceae might be related to the homeostasis in both Th₁/Th₂ and Treg/Th₁₇.     

Xyloglucan Oligosaccharides Hydrolysis by Exo-Acting Glycoside Hydrolases from Hyperthermophilic Microorganism Saccharolobus solfataricus

In the field of biocatalysis and the development of a bio-based economy, hemicellulases have attracted great interest for various applications in industrial processes. However, the study of the catalytic activity of the lignocellulose-degrading enzymes needs to be improved to achieve the efficient hydrolysis of plant biomasses. In this framework, hemicellulases from hyperthermophilic archaea show interesting features as biocatalysts and provide many advantages in industrial applications thanks to their stability in the harsh conditions encountered during the pretreatment process. However, the hemicellulases from archaea are less studied compared to their bacterial counterpart, and the activity of most of them has been barely tested on natural substrates. Here, we investigated the hydrolysis of xyloglucan oligosaccharides from two different plants by using, both synergistically and individually, three glycoside hydrolases from Saccharolobus solfataricus: a GH1 β-gluco-/β-galactosidase, a α-fucosidase belonging to GH29, and a α-xylosidase from GH31. The results showed that the three enzymes were able to release monosaccharides from xyloglucan oligosaccharides after incubation at 65 °C. The concerted actions of β-gluco-/β-galactosidase and the α-xylosidase on both xyloglucan oligosaccharides have been observed, while the α-fucosidase was capable of releasing all α-linked fucose units from xyloglucan from apple pomace, representing the first GH29 enzyme belonging to subfamily A that is active on xyloglucan.     

Pectic Galactan Polysaccharide-Based Gene Delivery System for Targeting Neuroinflammation

Treating neuroinflammation-related injuries and disorders through manipulation of neuroinflammation functions is being heralded as a new therapeutic strategy. In this study, a novel pectic galactan (PG) polysaccharide based gene therapy approach is developed for targeting reactive gliosis in neuroinflammation. Galectin-3 (Gal-3) is a cell protein with a high affinity to β-galactoside sugars and is highly expressed in reactive gliosis. Since PG carries galactans, it can target reactive gliosis via specific carbohydrate interaction between galactan and Gal-3 on the cell membrane, and therefore can be utilized as a carrier for delivering genes to these cells. The carrier is synthesized by modifying quaternary ammonium groups on the PG. The resulting quaternized PG (QPG) is found to form complexes with plasmid DNA with a mean diameter of 100 nm and have the characteristics required for targeted gene therapy. The complexes efficiently condense large amounts of plasmid per particle and successfully bind to Gal-3. The in vivo study shows that the complexes are biocompatible and safe for administration and can selectively transfect reactive glial cells of an induced cortical lesion. The results confirm that this PG-based delivery system is a promising platform for targeting Gal-3 overexpressing neuroinflammation cells for treating neuroinflammation-related injuries and neurodegenerative diseases.     

PUL-Mediated Plant Cell Wall Polysaccharide Utilization in the Gut Bacteroidetes

Plant cell wall polysaccharides (PCWP) are abundantly present in the food of humans and feed of livestock. Mammalians by themselves cannot degrade PCWP but rather depend on microbes resident in the gut intestine for deconstruction. The dominant Bacteroidetes in the gut microbial community are such bacteria with PCWP-degrading ability. The polysaccharide utilization systems (PUL) responsible for PCWP degradation and utilization are a prominent feature of Bacteroidetes. In recent years, there have been tremendous efforts in elucidating how PULs assist Bacteroidetes to assimilate carbon and acquire energy from PCWP. Here, we will review the PUL-mediated plant cell wall polysaccharides utilization in the gut Bacteroidetes focusing on cellulose, xylan, mannan, and pectin utilization and discuss how the mechanisms can be exploited to modulate the gut microbiota.     

甜玉米芯多糖对胰岛素抵抗HepG2细胞糖代谢功能的影响

目的：探讨甜玉米芯多糖（sweet corncob polysaccharide，SCP）组分SCP-80-I对胰岛素抵抗HepG2（insulin resistant HepG2，IR-HepG2）细胞糖代谢功能的影响。方法：确立IR-HepG2细胞模型建立的最佳条件，并由此建立IR-HepG2细胞模型；分别以50、100、200、400 μg/mL剂量的SCP-80-I孵育细胞24 h，评价其对细胞葡萄糖消耗的影响，同时利用噻唑蓝法评价其细胞毒性；检测氧化应激标志物超氧化物歧化酶（superoxide dismutase，SOD）、丙二醛（malondialdehyde，MDA）及活性氧（reactive oxygen species，ROS）的水平，测定细胞内糖原积累水平及糖酵解关键限速酶己糖激酶（hexokinase，HK）、丙酮酸激酶（pyruvate kinase，PK）的活力。结果：确立以1×10－6 mol/L胰岛素处理24 h作为诱导IR-HepG2细胞形成的最佳条件，并成功建立IR-HepG2细胞模型；在孵育实验中，SCP-80-I能极显著增加IR-HepG2细胞的葡萄糖摄取量（P＜0.01），细胞活力随SCP-80-I质量浓度的增加呈先上升后下降的趋势；200 μg/mL SCP-80-I处理组与模型对照组相比，胞内MDA含量极显著下降，SOD活力极显著提高，ROS水平极显著下降（P＜0.01）；胞内糖原含量极显著增加（P＜0.01），HK与PK活力极显著增加（P＜0.01）。结论：推测SCP-80-I的降血糖功效与其缓解氧化应激所造成的肝脏细胞损伤，改善胰岛素抵抗肝脏细胞的糖代谢功能有关。