类蛋白反应修饰的牡蛎肽锌结合物的生物利用性

通过类蛋白反应(Plastein)修饰制备具有较高锌离子结合能力的牡蛎源肽(EVPPEEH),其锌结合能力为161 mg/g。以缺锌型SD大鼠为试验模型,以牡蛎酶解肽-锌结合物OPZ、类蛋白反应修饰的牡蛎酶解肽-锌结合物LPZ和ZnSO4(ZS)为对照,研究牡蛎源肽(EVPPEEH)与锌的结合物(MZ)在体内的生物利用率和生物利用途径。结果表明:MZ组大鼠血清锌水平,股骨锌储备量及肝脏锌含量和肾脏锌含量均显著高于各对照组。脾脏锌含量MZ组和LPZ组恢复程度相似,均显著高于OPZ组和ZS组。MZ组和各对照组大鼠体重和摄食量均显著增加,效果相似。大鼠小肠转锌蛋白(ZnT1)的表达量MZ组与无机锌组差异不是很明显,而小肽转运蛋白(PepT1)的表达量MZ组最高,相对于ZS组上调了20%,显著高于各对照组,说明大鼠小肠对MZ的吸收利用一部分是通过传统锌离子途径,另一部分是通过小肽途径。MZ有望成为一种新型高效的补锌制剂。     

罗非鱼鳞胶原蛋白肽锌螯合物制备工艺优化

为了获得罗非鱼鳞胶原蛋白肽锌螯合物的最佳制备工艺,采用响应面法进行优化其制备工艺,建立了肽锌螯合率与pH、肽锌质量比、时间和温度的数学模型。得到最佳制备工艺参数为:pH 5.0、肽锌质量比2.5∶1、时间35 min和温度54℃,肽锌螯合率的预测值为92.79%,验证试验值为91.96%,与预测值无显著性差异。     

Study of stain-eliminating textiles using ZnO nanoparticles

We report the synthesis and characterization of nano-sized zinc oxide (ZnO) particles and their application on cotton and polyester/cotton (P/C) fabrics for imparting and evaluating the stain-eliminating or stain-release function by surface modification. The ZnO nanoparticles were produced in different conditions of temperature (90°C or 150°C) and reacting medium (water or 1,2-ethanediol). A high temperature was necessary to obtain small mono-dispersed particles. Fourier transform infrared spectroscopy, transmission electron microscopy, and X-ray powder diffractometry were used to characterize the nanoparticles' composition, their shape, size, and crystallinity, respectively. ZnO nanoparticles were then applied to 100% cotton and P/C samples to impart stain-eliminating function to the treated textiles. The effectiveness of the treatment was assessed through a standardized test procedure for stain release. The results have been recorded, analyzed, and reported in this paper.     

正交试验优化花生肽螯合锌的制备工艺

研究了花生蛋白水解物和锌离子制备肽锌螯合物的工艺条件,以螯合率为评价指标,考察肽与锌的质量比、反应pH、反应温度和反应时间对螯合反应的影响。在单因素试验基础上,采用4因素3水平正交法确定花生肽-锌螯合物的制备工艺。最佳工艺条件:花生肽-锌质量比4∶1、反应体系pH 6.0、反应温度50℃、反应时间40 min。在此条件下,锌的螯合率为57.04%。     

多肽-锌配合物的生物功能活性及安全性

多肽-锌配合物是一种具有多种生物功能活性的新型有机金属化合物,该配合物主要来源于三个方面：一是通过人工制备的多肽与Zn2+的配合作用合成多肽-锌配合物,二是通过动植物蛋白质酶解获取的多肽与Zn2+的配合作用合成多肽-锌配合物,三是从动植物组织中直接提取多肽-锌配合物。由于构成多肽-锌配合物的配基多肽的不同而具有不同的组成和结构,从而体现出不同的生物功能活性,包括抗菌抑菌、生理机能调节和免疫调节、抗氧化作用等。本文就国内外对多肽-锌配合物的生物功能活性及安全性的研究现状、最新研究进展及未来研究方向等方面进行综合阐述。提出今后应加强对其毒理学特性和应用安全性方面的研究,以推进多肽-锌配合物的实际应用和产业化开发。     

Zinc Oxide Nanoparticles: Synthesis,Antimicrobial Activity and Food Packaging Applications

Zinc oxide (ZnO) is an inorganic compound widely used in everyday applications. ZnO is currently listed as a generally recognized as safe (GRAS) material by the Food and Drug Administration and is used as food additive. The advent of nanotechnology has led the development of materials with new properties for use as antimicrobial agents. Thus, ZnO in nanoscale has shown antimicrobial properties and potential applications in food preservation. ZnO nanoparticles have been incorporated in polymeric matrices in order to provide antimicrobial activity to the packaging material and improve packaging properties. This review presents the main synthesis methods of ZnO nanoparticles, principal characteristics and mechanisms of antimicrobial action as well as the effect of their incorporation in polymeric matrices. Safety issues such as exposure routes and migration studies are also discussed.     

微波固相合成谷氨酸锌的工艺研究

以谷氨酸钠和氧化锌为原料,研究了在固体状态下,通过微波辐射一步快速合成谷氨酸锌,并对其合成工艺条件进行研究。结果表明最佳反应条件为配体物质的量比为1.2∶1,引发剂量为12 mL,微波时间为150 s,微波功率为500 W,在此条件下合成的谷氨酸锌螯合物的螯合率为83.02%。同时采用红外光谱对产品结构进行了分析确认,试验结果表明,制得的为谷氨酸锌内络盐,其中谷氨酸质量分数为63.28%,Zn质量分数为26.43%,在水溶液中,谷氨酸锌非常稳定;生理条件下,产品溶解性优于ZnO和ZnSO4.H2O。     

Characterization of the mineral content of a physical sunscreen emulsion and its distribution onto human stratum corneum

When using physical sunscreens, protection and aesthetic aspects are directly related to particle size and mineral distribution onto skin. These investigations aimed to characterize the different mineral raw materials entering into the composition of a specific sunscreen emulsion and to assess the distribution of the sunscreeen agents at the surface of human stratum corneum. X-ray diffractometry revealed the crystallographic features of the TiO2 and ZnO crystals. Frequency distributions of crystal length and aspect ratio were determined for the zinc oxide which presented the largest particle size and varying shapes. Scanning and transmission electron microscopy disclosed structural information. The results reported in this study specify the characteristics of the oxide particles involved in the formulation and show a satisfactory mineral distribution along the irregular topography of the skin. No intracellular penetration was noted.     

硼酸锌/氢氧化铝对聚氯乙烯纺织结构材料阻燃及稳定性的影响

为改善聚氯乙烯（PVC）纺织结构材料的阻燃、抑烟、防熔滴等性能,采用无机阻燃剂硼酸锌和氢氧化铝协同作用制备阻燃PVC纺织结构材料。利用极限氧指数仪、烟密度仪、热重分析仪、扫描电子显微镜分析了硼酸锌和氢氧化铝复配对PVC纺织结构材料性能的影响。结果表明：硼酸锌和氢氧化铝复配阻燃PVC纺织结构材料具有优异的阻燃性、抑烟性、防熔滴性,随着硼酸锌含量的增加,抑烟效果更佳;老化处理对PVC稳定性存在一定程度的影响,其极限氧指数值随热氧老化时间的延长先增加再降低,且随光氧老化时间的延长而增加。     

啤酒酵母富集锌的工艺研究

啤酒酵母生长周期短,对微量元素吸收率高,是可以将金属离子由无机态转化为有机态的理想载体。应用啤酒酵母将无机锌转化为有机锌,可以作为锌补充制剂,从而改善生物体对无机锌吸收利用难,避免出现肠胃不适甚而胃出血的现象,达到促进智力发育、增强免疫力等功效。研究了啤酒酵母富锌的最适培养条件。     

在金刚石薄膜上生长微米／纳米结构氧化锌

金刚石是非常重要的宽禁带半导体材料,n-型氧化锌与p-型金刚石的结合成为半导体研究的热点。该研究实现了金刚石薄膜上生长六角纤锌矿结构氧化锌（ZnO）微米／纳米结构。生长初期或ZnO饱和蒸气压较低时,ZnO晶粒多沉积在金刚石薄膜的晶界和棱边处,随着沉积时间的增加或反应气氛中气态ZnO浓度的增加,会有大量微米／纳米结构的ZnO生成,并覆盖整个金刚石薄膜表面。对ZnO在金刚石薄膜表面生长机制及反应气氛对金刚石的钝化作用进行了分析。     

Structural characterisation,gastrointestinal digestion stability and transepithelial transport study of casein peptide–zinc chelate

In this study, a promising nanoparticle of casein peptide–zinc chelate (CNP-Zn) for zinc supplementation was obtained. The structure properties and transepithelial transport mechanism were investigated. The amino acid composition, particle size, zeta potential and microstructure were significantly changed after chelation with zinc ions. The results of fourier-transform infrared spectroscopy suggested that the oxygen atoms from both the carboxyl and carbonyl groups, amides, were responsible for zinc chelation. After gastrointestinal digestion, over 40% of zinc remained bound in CNP–Zn. The transepithelial transport results showed that paracellular route and PepT1 transporter were involved in the absorption of CNP–Zn, and almost 50% of the bound zinc was co-transported with peptides. These findings would provide a relatively comprehensive cognition for developing efficient dietary zinc carriers.     

Antifungal properties of Zinc‐compounds against toxigenic fungi and mycotoxin

Antifungal and antimycotoxin properties of zinc (Zn) compounds were evaluated against toxigenic strains of Fusarium graminearum, Penicillium citrinum and Aspergillus flavus. In addition, was verified the activity of these Zn‐compounds on conidia production, hyphae morphological alterations, mortality and reactive oxygen species (ROS) production. The Zn‐compounds treatments utilised were zinc oxide nanoparticles (ZnO‐NPs), zinc oxide (ZnO), zinc sulphate (ZnSO₄) and zinc perchlorate (Zn(ClO₄)₂). The Zn‐compounds effect on growth diameter of fungal colony was concentration dependent. Two treatments (ZnSO₄ and Zn(ClO₄)₂) completely inhibited the fungal growth and their ability to produce mycotoxins. The conidia production of all fungi also was reduced after the treatment with Zn‐compounds. Morphological alterations occurred in the treated fungi showing hyphae damage. The treatments led to cell death and ROS production observed in the fungi hyphae. ZnSO₄ and Zn(ClO₄)₂ were the compounds that showed better results as antifungal, presenting antimycotoxin activity and caused alterations in the fungi cell structure.     

魔芋葡甘聚糖/油酸修饰纳米ZnO复合抗菌膜的制备与表征

为提高纳米氧化锌（ZnO）在魔芋葡甘聚糖（konjac glucomannan，KGM）中的分散性，以增强纳米复合膜的抗紫外线性能和抗菌性能，通过油酸（oleic acid，OA）对纳米ZnO进行修饰，制备OAZnO溶液，并采用浇铸法制备KGM/OAZnO纳米复合膜，通过流变学分析、傅里叶变换红外光谱分析、X射线衍射分析、微观结构观察、热重分析以及理化性质测定，研究OAZnO的添加对KGM膜结构和理化性质的影响。结果表明，OA提高了纳米ZnO的分散性，傅里叶变换红外光谱分析证实纳米ZnO与KGM分子间形成了较强的氢键，X射线衍射光谱结果表明纳米ZnO中的Zn2＋与KGM链上的—OH形成配位键；同时，适量OAZnO（0.49 mL）使纳米复合膜包装机械性能和阻水性能得到增强，其水蒸气透过率较KGM膜降低了35.62%，拉伸强度提高了79.26%。此外，紫外光谱分析和抗菌实验结果表明KGM/OAZnO纳米复合膜具有较强的紫外阻隔性能和抗菌性能。综上，OAZnO的添加可以提高纳米复合膜综合性能，且OAZnO溶液添加量为0.49 mL时最强，可以作为功能性食品包装膜。     

ZnO纳米晶的表征

讨论了用甲苯 /SDS/正戊醇 /水溶液的微乳液体系制备的ZnO钠米晶的特征 .结果表明 ,该ZnO纳米晶的表面包覆了一层表面活性剂SDS ,ZnO的含量达 92 .3% ,平均晶粒度为 12 .9nm ,粒度分布均匀 ,分散性好 ,具有良好的吸收紫外线的特性 ,是一种良好的防晒助剂     

酵母对无机锌的富集及其影响因素研究

在培养基中添加无机锌，利用生物转化技术，通过酵母的生命活动，将无机锌有效地富集到细胞内，研究锌离子浓度对酵母生长繁殖、细胞含锌量、锌富集率及酵母发酵力的影响，并通过控制锌离子浓度，使酵母细胞既能富集锌，又对其发酵力不产生显著的影响，以便将仍具有发酵活力的富锌酵母用于食品加工之中。研究结果表明，锌离子浓度对酵母的生长繁殖和富集能力影响较大，浓度越高，酵母细胞含锌量越大。但无机锌对酵母细胞有显著的损伤，且这种损伤是非遗传性的，当无机锌去掉后，酵母细胞形态又恢复正常。     

保加利亚乳杆菌对微量元素硒、铬、锌的富集

硒、铬、锌是人体必需的具有一定功能作用的微量营养元素,有机态微量元素吸收迅速且安全,吸收率高。研究了保加利亚乳杆菌对硒、铬、锌通过生物转化将无机态微量元素富集转化为细胞内的有机态微量元素,结果表明:适当提高培养基中硒、铬、锌的浓度,有利于保加利亚乳杆菌的生长和微量元素有机态的富集转化;但是当硒浓度超出一定范围时,则抑制保加利亚乳杆菌的生长。这3种元素中,保加利亚乳杆菌对锌的富集转化能力最强,铬次之,而对硒的富集转化能力最弱。     

Antimicrobial activities of ZnO powder-coated PVC film to inactivate food pathogens

In this work, the effects of two different amounts of zinc oxide (ZnO) nanoparticles on the antimicrobial activities of poly (vinyl chloride)-based films to inactivate food pathogens were investigated. Results showed that the ZnO-coated film exhibited a good inhibition effect on the growth of Escherichia coli and Staphylococcus aureus and its ability was attributed to the ZnO nanoparticles. The ZnO-coated films exhibited more effective antibacterial activity for S. aureus . However, antifungal activity of the ZnO-coated films (20 mm × 25 mm) against Aspergillus flavus and Penicillium citrinum was not observed. It is likely due to the complexity of the fungal cell wall and the ZnO nanoparticles without UV light irradiated or the insufficient amount of nanoparticles. Our findings reveal that ZnO nanoparticles have a good potential to be coated on a plastic film to make antimicrobial packaging against bacteria such as E. coli and S. aureus .     

高压电性静电纺柔性氧化锌/聚偏氟乙烯复合纤维膜

为了获得环保、柔软、透气和高压电性的材料,增加压电材料在纳米发电机,传感器,可穿戴电子器件等方面的应用,采用静电纺丝技术制备出了高压电性的氧化锌/聚偏氟乙烯（ZnO/PVDF）复合纤维膜材料。通过扫描电子显微镜、全反射傅里叶变换红外光谱仪、X射线衍射仪及示波器对压电复合纤维膜的形貌、结构和压电性进行了表征。结果表明：在PVDF基材中加入适量的氧化锌纳米颗粒(ZnO NPs)可在一定程度上提升PVDF纤维膜的结晶度和电活性β晶型含量增加,使PVDF中总的β晶型含量增加;同时,ZnO NPs自身具有压电性,也可进一步提升复合材料的压电性,使复合纤维膜的输出电压显著提高。当ZnO NPs质量分数为30%时,复合膜的输出电压高达60V,与纯PVDF纤维膜的输出电压相比,复合纤维膜的压电性提升了200%。     

Effect of soy peptide on brewing beer

Here, we examined the effect of soy peptides (SPs) on the fermentation and growth of Yeast Bank Weihenstephan 34/70 (W34/70), a bottom-fermenting yeast. We compared fermentation for SP with that for a free amino acid (FAA) mixture having the same amino acid composition as SP, as a nitrogen source. Maltose syrup was used as a carbon source, and the medium contained excess amounts of essential minerals and vitamins. We observed that SP was better than FAA mixture at promoting fermentation and growth and that much more beta-phenylethyl alcohol was produced during fermentation with SP than with FAA mixture. Subsequently, we compared fermentations with the FAA mixture and selected mixtures containing various dipeptides of Phe as a nitrogen source. We found that the rates of Phe metabolism and beta-phenylethyl alcohol generation were much higher when Phe was presented as a dipeptide (Phe-Asp, Phe-Leu, or Phe-Phe) than when presented as FAA. These results show that amino acids such as Phe are absorbed more rapidly when presented as a peptide than as FAA, resulting in a more rapid production of beta-phenylethyl alcohol.