Changes in polyphenol fractions and bacterial composition after in vitrofermentation of apple peel polyphenol by gut microbiota

The changes in polyphenol fractions after in vitro fermentation of apple peel polyphenol (APP) by gut microbiota as well as the effects of APP on the growth, pH value, short-chain fatty acids (SCFAs) production and intestinal flora composition of gut microbiota fermentation were firstly explored in this study. The relative abundance of Lactobacillus in the APP group was 49.55% with an increment of 49.40% compared with the blank group, while that of Bifidobacterium was 13.32%. Moreover, the flora produced 37.093 ± 0.478 mM of SCFAs including acetic acid, propionic acid, butyric acid and valeric acid during the process of fermentation, thus reduced the environmental pH value. In addition, polyphenol fractions in APP were altered by gut microbiota fermentation to some extent, for example, glycosides were hydrolysed to aglycones. These findings suggested APP as a potential prebiotic agent to alleviate the disorder of intestinal flora.     

Highly-hydrophobic nanofiber mat for efficient colonic delivery of lactoferrin: Preparation,characterization and release mechanism

Lactoferrin (Lf) is a bioactive protein with varied biological effects. To improve its anti-digestive stability in oral administration, a novel nanocarrier with high hydrophobicity for colonic delivery of Lf was creatively developed by modified coaxial electrospinning. First, a suitable biocompatible solvent, acetic acid, was screened as the mono-solvent for ES100 electrospinning, creating highly-hydrophobic ES100 nanofiber mat (contact angle = 133.8^o). Then, Lf-loaded W/O emulsion was prepared as the core fluid to ensure the successful coaxial electrospinning and generate Lf encapsulated core/shell nanofiber mat (ES@Lf). Lf was demonstrated maintaining structural integrity and anti-colon cancer activity during encapsulation and oral delivery. In vitro assay indicated 92.3% Lf was sustainably released in colon, and its release followed a complex mechanism in which the erosion was dominant. Instead of pH-dependent erosion, the synergistic action through gut microbiota adhesion and their metabolites, especially short-chain fatty acids, was illustrated for disintegration of ES@Lf nanofiber for the first time.     

Changes in the content and antioxidative activity of β-carotene and its metabolite vitamin A during gastrointestinal digestion and absorption and optimisation of HPLC-based detection

The β-Carotene (BC), an important precursor of vitamin A (VA), possesses antioxidant activity but is fat-soluble and has low bioavailability. In previous in-vitro assays evaluating antioxidant and 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) free radical scavenging, both BC and VA showed a strong ability to scavenge radicals and protected cells from oxidative stress. Here, we used artificially simulated gastrointestinal digestion and Caco-2 cell absorption models to evaluate the bioavailability of the BC during gastrointestinal digestion and absorption using high-performance liquid chromatography (HPLC) analysis. We observed high absorptive and transfer rates of BC and detected retinol metabolites (Vitamin A). Therefore, BC can be detected in the acidic gastrointestinal environment using HPLC. Optimised method provided better separation of BC and VA in the column, improving the accuracy of the test results.     

Cold plasma hydrophilization of soy protein isolate and milk protein concentrate enables manufacturing of surfactant-free water suspensions. Part I: Hydrophilization of food powders using cold plasma

In this study, we found that treatment with cold plasma influenced the wetting properties of soy protein isolate and milk protein concentrate powders. Cold plasma treatment significantly decreased the apparent contact angle of the powders, indicating hydrophilization of the powders. Cold radiofrequency low-pressure plasma treatment had a larger effect on powder wettability than corona atmospheric plasma discharge. In addition, cold plasma treatment had a more noticeable effect on the wettability of the hydrophobic milk protein concentrate than on the inherently hydrophilic soy protein isolate. Both the soy protein isolate and milk protein concentrate demonstrated zero hydrophobic recovery over time. Scanning electron microscopy showed that cold air plasma treatment of food powders caused minor surface oxidation, though these changes were not observed using FTIR spectroscopy. We suggest that cold plasma treatment has important implications for the production of stabilizer-free food suspensions.     

总变差模型在书画打印宣纸印刷质量预测中的应用

为了建立适用于书画打印宣纸印刷质量的预测模型,本研究测量了14种书画打印宣纸的粗糙度、白度、不透明度、定量、光泽度和针对宣纸特别设定的帘纹深浅以及帘纹疏密度等表面物理参量,并在相同条件下,使用喷墨打印设备输出并测量印品色度值,利用总变差模型构建去除帘纹色差的测定方法,得到与人眼视觉特征相符的色差。运用GRNN广义回归神经网络结合书画打印宣纸表面物理参量与宣纸去帘纹后的色差值,建立预测模型。结果表明,该模型能够在仅测量书画打印宣纸表面物理参量的情况下,便能较为准确地预测书画打印宣纸印刷质量,为书画打印宣纸印刷前的选纸工作提供指导依据。     

利用非糖物质快速鉴别单花蜂蜜

本文利用非糖物质快速鉴别四种常见的单花蜂蜜(枸杞蜂蜜、荆条蜂蜜、枣花蜂蜜和洋槐蜂蜜)。利用固相萃取除糖提取蜂蜜非糖物质,并用高效液相色谱(HPLC)结合化学计量学进行蜂蜜花源的判定。发现了四种单花蜂蜜的非糖特征标志物。芦丁、丁香酸甲酯、阿魏酸的含量在四种蜂蜜中差异最大。对羟基苯甲酸和脱落酸在枸杞蜂蜜中平均含量分别为0.59μg/g和0.42μg/g,可作为枸杞蜂蜜的花源标志物;对香豆酸和肉桂酸在荆条蜂蜜中平均含量为0.08μg/g和0.05μg/g,可作为荆条蜂蜜的潜在花源标志物;阿魏酸、异阿魏酸是枣花蜂蜜的特征标志物,平均含量分别为0.40μg/g和0.76μg/g;洋槐蜂蜜的特征标志物是芦丁和丁香酸甲酯,平均含量为0.08μg/g和0.14μg/g。利用高效液相色谱指纹图谱结合化学计量学方法(主成分分析和判别分析),四种单花蜂蜜依据其花源被成功区分。本研究对蜂蜜真实性判定有重要参考价值,为后续蜂蜜真伪鉴别奠定基础。     

The genetic diversity of two invasive sympatric bivalves (Corbicula fluminea and Dreissena polymorpha) from Lakes Garda and Maggiore,Northern Italy

Corbicula fluminea and Dreissena polymorpha are two non-indigenous species (NIS), known to provoke biodiversity loss of the existent native communities and alterations in the ecosystem functioning structure. Both of these NIS have successfully founded well established populations in Lakes Maggiore and Garda (Northern Italy). Here, we evaluated the mitochondrial COI genetic diversity of C. fluminea and D. polymorpha populations from the aforementioned lakes. The COI gene analysis revealed one C. fluminea haplotype, belonging to the FW5 androgenetic invasive lineage. Two D. polymorpha haplotypes – LM1 and LM2 – were detected in Lake Maggiore. The D. polymorpha comparative phylogeographical haplotype analysis between Lake Maggiore and the retrieved COI data available from Lake Garda revealed that LM1 is the dominant haplotype in both populations, whereas LM2 a rare haplotype was only detected in Lake Maggiore. These findings contribute for a better understanding of the demographic history of these highly invasive species in these Italian lakes, thus suggesting that C. fluminea and D. polymorpha populations present a similar genetic pattern. The low genetic diversity detected in both of these bivalve populations seems to reflect a pre-existent low genetic pool prevenient from the introductory source(s).     

Physical stability of infant milk formula made with selectively hydrolysed whey proteins

A whey protein ingredient, in which β-lactoglobulin was selectivity hydrolysed, was evaluated during manufacturing of infant formulae. Three model infant milk formula (IMF) powders were produced containing: non-hydrolysed (NH) proteins (60:40; whey proteins:caseins); partially hydrolysed (PH) caseins and whey proteins; and selectively hydrolysed (SH) whey proteins. After homogenisation, particle size (D[4,3]) of the SH formulae was similar (P > 0.05) to NH formulae and was significantly (P < 0.05) smaller than PH formulae. Prior to spray drying (∼55% w/w), the viscosity of SH formulae (14.8 ± 0.3 mPa s) was significantly lower (P < 0.05) than that of the NH (48.6 ± 0.8 mPa s) or PH formulae (27.6 ± 1.5 mPa s). Surface free fat, wettability and glass transition temperature of powders were not significantly (P > 0.05) different. IMF manufactured with SH ingredients have applications in high dry matter processes with potential for reduced energy costs in spray drying.     

Synergetic improvement strategy on thermoelectric performance of CuAlO2 compacts

We fabricated Sr and Ca-doped CuAlO₂ compacts from the mixed powder of CuO, Cu₂O, Al₂O₃, and SrO or CaO by multi-pass hot pressing followed by spark plasma sintering (SPS). The XRD results showed the reaction of CuO, Cu₂O and Al₂O₃ was rather complete and only CuAlO₂ single phase was formed when the additive amount of SrO or CaO was appropriate. Multi-pass hot pressing increased the relative density and the usage of plate-like Al₂O₃ as reaction raw material enhanced the orientation degree. In spite of performance improvement conflicts through elemental doping, density increase and orientation improvement, the measurement on the thermoelectric performance indicated that the electrical resistivity, Seebeck coefficient, power factor, dimensionless figure of merit (ZT) were improved to varying degrees through the synergetic action of elemental doping, density increase, and orientation control. The highest power factor and ZT of the Ca-doped CuAlO₂ compacts reached 1.54?×?10^?4 W?m^?1 K^?2 and 0.015 at 973?K, respectively. The thermoelectric performance was higher than those of CuAlO₂ at the same temperature in published work before.     

辊式涂布法构建纸基牢固超疏水表面

采用辊式涂布的方法在纸基材料上构建超疏水表面，并对超疏水表面的牢固性、自清洁性和疏水性能进行评价。用γ-氨丙基三乙氧基硅烷和1H,1H,2H,2H-全氟辛基三乙氧基硅烷（POTS）对微米级和纳米级两种尺寸的TiO₂粒子进行疏水改性处理，然后将改性后的微/纳米TiO₂涂布在纸基材料表面。采用红外光谱（FTIR）对改性后的微/纳米TiO₂的化学组成进行了分析，采用扫描电镜（SEM）对涂布纸表面结构进行了表征，通过接触角、耐磨性和自洁净测试评价了涂层表面的超疏水性、牢固性和自清洁性。改性TiO₂的FTIR分析显示在1000～1500cm^-1之间出现多个C—F键的伸缩振动峰，表明POTS通过化学键与TiO₂表面发生了结合。涂布纸表面的SEM分析可以看出，纸基材料表面上均匀分布了微米和纳米尺寸的TiO₂颗粒，具备了类似荷叶表面微-纳结构的粗糙表面。涂层表面的水接触角为153°±1.5°，滚动角为3.5°±0.5°，水滴在涂层表面呈球形，极易滑落，涂层在水中浸泡7天后，接触角没有发生明显变化，表明纸张表面具备了优异的超疏水性能，且疏水稳定性较好。涂层表面经过10次循环磨损试验后，接触角仍能达到150°，滚动角为9°，表明机械摩擦没有对涂布纸表面的化学成分和粗糙结构造成明显的破坏，超疏水表面的牢固性较好。自洁净测试表明，涂布纸表面具有良好的自清洁和防污性能。该工艺过程操作简单，易于实现工业化生产，为在纸基表面构建综合性能优异的超疏水表面提供了一种新的便利途径。