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.     

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.     

Furan fatty acid concentrations in tea infusions prepared from green,black, and herbal teas

Furan fatty acids (FuFAs) are valuable antioxidants with highly effective radical scavenging properties which are widely distributed at low levels in food. Previous research indicated that tea is a valuable source of FuFAs. However, tea is only consumed in form of infusions. To fill this gap, we prepared infusions from different herbal, green, and black teas. Initial measurements with GC-MSMS of tea verified previous findings that 11-(3,4-dimethyl-5-penylfuran-2-yl)-undecanoic acid (11D5) was the prevalent FuFA in tea matrix. Therefore, 11D5 was quantified in tea infusions by means of UHPLC-MSMS equipment after mild alkaline hydrolysis. While herbal tea infusions were low or free of FuFAs, 11D5 was detectable in all samples of green and black tea infusions. Amounts of 11D5 were higher in green tea than in black tea. Moreover, Darjeeling tea infusions were by ~30% richer in 11D5 than black and green teas from other regions. Each cup of green and black tea infusion may provide 20–60 μg 11D5, which is about 5% of the amounts found in tea samples. Spread over the day, regular tea consumption may contribute to the intake of valuable FuFAs.     

基于跨临界CO2热泵的茶叶生产能源系统负荷削减潜力

乡村产业中的化石能源设备逐渐被电能技术替代，引起了乡村负荷波动增大、部分时段产生集中高负荷的问题。为了解决以上问题，将低品位清洁能源应用至乡村的茶叶生产中，针对烘茶全过程的工艺要求提出了跨临界CO₂热泵烘茶技术；并以某茶叶生产乡村为对象，对其代表台区的全年日用电量及产茶日负荷进行了分析，得出采用CO₂热泵烘茶后其负荷得到大幅度削减，整体可降低至原负荷的39.6%~46.8%，峰值负荷与平时负荷的比值由原本的13.6降至5.4~6.2。跨临界CO₂热泵应用至农产品生产中可有效缓解乡村供电压力。     

基于魅力工学的传统器物设计评价应用研究

目的 在传统器物的创新设计中,最重要的环节是了解消费者对所使用产品的不同感受与意向并转换为具体的设计要素.研究消费者心理的感性因素与传统器物设计元素之间的联系,确定设计要素,从而对产品进行创新设计,为提升传统器物附加值作出贡献.方法 以中国传统器物茶宠为例,首先对8位相关的茶宠专家进行访谈,通过魅力工学中的评价构造法整理并提取魅力因子,设计出问卷调查表;然后以访谈内容为依据,使用问卷调查法得到大众对茶宠的魅力评价,共回收84份有效问卷;最后应用数量化一类分析茶宠魅力因子影响权重.结果 得到了数量化一类统计表,选取了其中影响因素较大的魅力因子作为茶宠设计前的风格定调考量.结论 通过茶宠的研究案例证明了该理论的可行性,为未来传统器物的设计提供了更多元且新颖的设计依据.     

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。     

Extraction and characterisation of pectin polysaccharide from soybean dreg and its dispersion stability in acidified milk drink

In this study, pectin polysaccharide (SDPP) was obtained from soybean dreg (26.2% yield), and characteristics of SDPP were compared with those of soybean soluble polysaccharides (SSPS) and citrus pectin (HMP). The galacturonic acid and molecular weight of SSPS, SDPP or HMP were 11.8%, 40.6% or 70.2% and 112, 446, or 440 kDa. SDPP had similar viscosity and protein content to SSPS, and functional groups and linear structure to HMP. SSPS, SDPP or HMP differed in particle size of 260, 467 or 1195 nm and ζ–potential of −5.8, −14.6 or −23.5 mV at pH 4.0. The precipitation of acidified milk drink (AMD) was 6.31% without stabiliser or below 1.75% with 0.4% SDPP at pH 3.6–4.6. These results suggested that SDPP combines the structure and characteristic of HMP and SSPS, and AMD with SDPP had great stabilising behaviour at wider pH range (pH 3.6–4.6).     

不同水分工夫红茶贮藏过程中主要内含成分及感官品质变化研究

目的研究不同水分工夫红茶贮藏品质变化规律,为工夫红茶贮藏的适宜水分条件提供理论参考。方法系统比较不同水分工夫红茶(国家标准范围内)在自然贮藏条件下其主要内含成分及感官品质的变化。结果 1年贮藏期内,初始水分含量越低,含水率增长速度越快,总体上,茶叶初始水分含量高低决定贮藏过程中水分的高低。在短期贮藏(≤6月)时含水量越高的红茶中茶多酚、水浸出物保留量越多;长期贮藏(6月)时水分较低的红茶中茶多酚、水浸出物保留量越多。咖啡碱、可溶性糖在短期贮藏(≤6月)中水分含量适中的红茶中下降速度越慢;长期贮藏(6月)含水量较高的保留量越高。氨基酸含量在含水量越低的红茶中越高。初始水分含量高的红茶L*、a*、b*值均稍高于水分低的红茶。结论从综合品质的变化来看,本实验中以处理3含水率为5.93%的处理最好,处理2含水率为4.1%次之,处理1含水率为2.33%最差。