茅台镇酱香型白酒酿造环境中真菌菌群多样性分析

采用高通量测序技术结合数理统计软件分析方法，系统研究茅台镇酱香型白酒不同酿造轮次生产环境中的真菌菌群结构及特征。7 个轮次中共检测到4 个真菌门、212 个真菌属。根据各菌门、属的相对丰度，子囊菌门（Ascomycota）和担子菌门（Basidiomycota）是茅台镇酱香型白酒酿造环节中各酿造轮次的优势菌门，节担菌属（Wallemia）、复膜孢酵母属（Saccharomycopsis）为各轮次绝对优势真菌属。不同轮次环境样品中真菌组成结构的相似度较高，但其各轮次标志性真菌属存在差异。7 个酿造轮次共有相同真菌属56 个，在各轮次占主导地位，特征性真菌属在各轮次当中相对丰度和占比较小但种类丰富。Ascomycota最强节点为德巴利酵母属（Debaryomyces），Basidiomycota最强节点为红酵母属（Rhodotorula）。本研究揭示了茅台镇酱香型白酒不同酿造轮次环境中真菌菌群结构及其特征，为深入研究酱香型白酒酿造机理以及对酿造环境中微生物结构的解析提供了参考依据。     

发酵十字花科蔬菜中硫代葡萄糖苷代谢研究进展

硫代葡萄糖苷（简称硫苷）是十字花科蔬菜中一类重要的次生代谢物。在蔬菜发酵过程中，硫苷被代谢为异硫氰酸盐等活性产物，这些代谢产物具有抗氧化、抗癌、调节肠道菌群等多种生理功能。乳酸菌发酵对硫苷的代谢机制包括促进硫苷从蔬菜中释放，以及使其发生降解，且代谢作用既与乳酸菌种属相关，也与发酵体系的盐含量、金属离子、pH值以及蔬菜加热预处理相关。通过总结梳理发酵蔬菜硫苷代谢研究进展，并解析影响因素，为提高发酵蔬菜中活性硫苷代谢产物含量，提升发酵蔬菜的健康效应提供理论指引。     

Effect of light,food additives and heat on the stability of sorghum 3-deoxyanthocyanins in model beverages

This work aimed to evaluate the stability of sorghum 3-deoxyanthocyanins (DXA) in model beverages (pH 3.5) elaborated with crude sorghum phenolic extract, containing ascorbic acid and sulphite, under fluorescent light exposure and subjected to heat treatment. There was no significant difference in the DXA degradation during storage under light exposure (24.16%) and absence of light (20.72%). DXA degradation did not differ in the presence of ascorbic acid during storage under light exposure (23.99–25.38%) and absence of light (19.87–21.74%). The addition of sulphite caused an initial bleaching reaction, but as a reversible reaction, the anthocyanin content was higher on the last day of storage compared to the first day. There were no significant differences in total anthocyanin content of all treatments subjected to the heat treatment (80 °C for 5 and 25 min). Thus, crude DXA are very stable under light, additives and heat, and may be useful as natural food colourants.     

基于柠檬酸-铕纳米配位聚合物构建荧光探针快速检测汤煲中5’-肌苷酸含量

基于柠檬酸-铕金属有机纳米配体聚合物（citrate/europium lanthanide coordination polymer nanoparticles，Cit/Eu LCP NPs）构建快速检测肉品汤煲中5’-肌苷酸（inosine-5’-monophosphate，5’-IMP）的荧光探针。研究结果表明，5’-IMP对Cit/Eu?LCP?NPs有良好的荧光猝灭作用。在最佳条件下，该荧光探针在5’-IMP?2.5～200?μg/mL的质量浓度范围内呈现出良好的线性关系，检出限为0.17?μg/mL，且具备良好的抗干扰、稳定性和重复性。为了验证方法可行性，将该方法应用于实际鸡汤样品中的5’-IMP检测，测得加标回收率为97.85%～103.95%，可为快速检测肉品汤煲中5’-IMP提供新的思路和方法。     

果蔬中外泌体样纳米颗粒的分离、表征和应用研究进展

果蔬中的外泌体样纳米颗粒（exosome-like nanoparticles，ELNs）是由果蔬细胞释放的纳米级囊泡结构，与动物的外泌体具有类似的超微结构，但其脂质、蛋白质及核酸等化学成分具有显著差异，并具有独特的生物学功能。本文综述了2013年以来数十种果蔬中ELNs的相关研究进展，对其提取方法和表征手段进行了分析，重点分析了不同植物来源的ELNs中脂质、蛋白质和核酸类化学成分的组成差异，并对ELNs的潜在生理活性和载体功能进行了探讨，可为果蔬中ELNs的相关研究提供借鉴和启示。     

Fully dense hot pressed calcium cobalt oxide ceramics

The processing parameters have been optimized to achieve highly pure and fully dense pellets of calcium cobalt oxide (Ca₃Co₄O₉) from solid-state ball milled calcium carbonate and cobalt oxide mixtures, calcined at optimized temperature and time, and consolidated by hot-pressing. The microscopic, spectroscopic, and thermal analysis suggest samples with longer ball-milling time require less calcination time for synthesizing highly pure crystalline phases of Ca₃Co₄O₉, and provide 99.2 ± 0.5% relative density.     

Tunable‐focus negative poly(vinyl chloride) gel microlens driven by unilateral electrodes

Tunable‐focus microlenses are urgently required for compact optical products to replace digital zoom and obtain high‐quality images. An electrically controllable tunable‐focus negative microlens is proposed, which is based on an electroactive poly(vinyl chloride) gel plasticized by ecofriendly dioctyl terephthalate. The anode and cathode of the microlens are simply assembled on the same side of the electrorheological elastomer, which greatly saves space and allows the thickness of the proposed microlens to be less than 1 mm. By applying voltages ranging from 0 to 1000 V, the stable focus of the microlens is interestingly able to vary as wide as from –∞ to ?21.3 mm correspondingly. The proposed microlens is simple and thin but is flexible and stable and has a wide range of the focus variation, showing promising applications in minielectric and optical devices. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46136.     

Effects of sintering method and BiFeO3 dopant on the dielectric and ferroelectric properties of BaTiO3–BiYbO3 based solid solution ceramics

(0.95–x) BaTiO₃–0.05 BiYbO₃–x BiFeO₃ (x?=?0, 0.01, 0.02, and 0.04) (abbreviated as (0.95–x) BT–0.05 BY–x BFO) ceramics were fabricated by conventional sintering (CS) and microwave sintering (WS) methods. Effects of sintering method and BFO dopant on the microstructure and electric properties of (0.95–x) BT–0.05 BY–x BFO ceramics were comparatively investigated. X-ray diffraction showed that all CS and WS samples presented a single perovskite phase. It was also found that WS ceramics possessed denser microstructure and finer grains compared to CS samples as indicated by the surface morphology characterization. Dielectric measurements revealed that all samples exhibited the weak relaxation behavior; however, the degree of relaxation behavior of BT–BY based ceramic could be strengthened by addition of BFO and by WS method. Moreover, the temperature and frequency stability could be improved with doped BFO. The density of 0.93BT–0.05BY–0.02BFO ceramic was found to be the largest while that of 0.94BT–0.05BY–0.01BFO ceramic was the smallest, thus, the dielectric constant of 0.93BT–0.05BY–0.02BFO was significantly larger than that of 0.94BT–0.05BY–0.01BFO and 0.94BT–0.05BY–0.04 BFO ceramics. minimum dielectric constant of (0.95–x) BT–0.05 BY–x BFO ceramic was obtained at x?=?0.01. Ferroelectric measurements indicated that all samples showed the slim hysteresis loop. The remnant polarization (P_r) and coercive field (E_C) of (0.95–x) BT–0.05 BY–x BFO ceramics first decreased and then increased with increasing x，the minimum values were obtained at x?=?0.01. Moreover, P_r and E_C of WS ceramics were slightly larger than those of CS ceramics, indicating that higher density and larger grain sizes contributed to enhancing the ferroelectric characteristic. These findings indicate that addition of moderate amount of BFO and use of WS technique can strengthen the degree of relaxation behavior and improve the ferroelectric properties of BT–BY based ceramics.