Prolamin-based complexes: Structure design and food-related applications

Prolamins are a group of safe food additives that are biocompatible, biodegradable, and sustainable. Zein, gliadin, kafirin, and hordein are common prolamins that have been extensively studied, particularly as these form colloidal particles because of their amphiphilic properties. Prolamin-based binary/ternary complexes, which have stable physicochemical properties and superior functionality, are formed by combining prolamins with polysaccharides, polyphenols, water-soluble proteins, and surfactants. Although the combination of prolamins with other components has received attention, the relationship between the structural design of prolamin-based complexes and their functionalities remains uncertain. This review discusses the production methods of prolamin-based complexes, the factors influencing their structural characteristics, and their applications in the food industry. Further studies are needed to elucidate the structure–function relationships between prolamins and other biopolymers, as well as the toxicological effects of these complexes in food.     

莪术醇长循环脂质体的制备及体外抗乳腺癌作用研究

目的:制备莪术醇长循环脂质体并对其体外性质进行初步研究。方法:用薄膜分散法制备莪术醇长循环脂质体,对其形态、粒径和电位分布,包封率,体外释放和放置稳定性测定,并考察体外细胞摄取和细胞毒性。结果:制备得到的莪术醇长循环脂质体粒径为(150.3±4.0) nm,PDI为0.197±0.009,zeta电位(-24.5±0.7) mV。莪术醇长循环脂质体平均包封率为80.24%,在4 ℃条件下存放2个月粒径和含药量无明显变化。细胞摄取实验中载香豆素-6长循环脂质体可增强MDA-MB231细胞的摄取。莪术醇长循环脂质体对MDA-MB231细胞具有较强细胞毒性作用,且作用强于莪术醇普通脂质体和游离莪术醇。结论:制备的莪术醇长循环脂质体包封率高,稳定性好,莪术醇长循环脂质体可增强乳腺癌MDA-MB231细胞的摄取及体外细胞毒性。     

Stochastic effects and corona discharge for the Shroud body image generation

Answers and specifications to the comments of G. Fanti on our recent work are presented. G. Fanti invited us to revise our work, taking into account the recent discoveries on the Shroud of Turin: double superficiality of the image, corona discharge as possible source of the image formation, and continuous variation of color density of the linen fibrils. Our work was mainly devoted to investigate the macroscopic process able to explain almost all characteristics of the Shroud body image, and for such a purpose cited literature was appropriate. About the microscopic processes able to trigger the yellowing of the fibrils constituting the Shroud body image, we could also consider the corona discharge, but further investigations and deepening are necessary.     

生物膜中蛋白质/油脂的交互作用

小分子和蛋白质间的分子交互作用,例如油脂与蛋白的结合,在各种生物学过程中是很基本和重要的.油脂/蛋白质交互作用在生物膜的组装中起到了核心作用,是深入了解膜结构与功能的中心环节.目前,它们的作用机理在国内尚未有详细报道,因此介绍一些油脂/蛋白质交互作用在结构方面的新信息,叙述这种交互作用的专一性特征以及油脂结构对膜蛋白功能的影响具有一定的意义.此外,还描述了蛋白质/油脂交互作用的动力学研究,介绍了一些以动力学表面张力检测蛋白/油脂交互作用的方法.     

乳清分离蛋白-植物甾醇纳米颗粒的制备与表征

本研究旨在使用乳清分离蛋白(Whey protein isolate, WPI)和植物甾醇(Phytosterols, PSs)采用超声辅助反溶剂沉淀法制备不同质量比的乳清分离蛋白-植物甾醇(WPSs)纳米颗粒,采用动态光散射技术、扫描电子显微镜、傅里叶红外光谱等技术对样品的形貌和结构进行表征,并对样品的pH稳定性、盐稳定性及体外释放进行了研究。结果表明：WPI/PSs质量比从50:1降低到10:1时,WPSs纳米颗粒粒径减小(252.77 ~ 215.90 nm),颗粒表面Zeta负电位增加(-31.27 ~ -37.37 mV),PSs包封率降低(95.39 ~ 81.55%);差示扫描量热结果表明PSs成功包埋在WPI中;红外光谱分析表明,PSs改变了WPI的二级结构;微观结构显示,随着PSs浓度的增加,WPSs纳米颗粒逐渐从清晰的球形变成网络结构、块状结构。另外,WPI/PSs质量比低于25:2时,WPSs纳米颗粒的复溶性较差。研究还发现,这些颗粒在高浓度的盐环境中以及在模拟胃条件下具有良好的稳定性。该研究证实,WPI包埋PSs后,其结构和形貌发生了改变,并且有利于小肠对PSs的吸收。     

Novel corona discharge treatment of cotton fabric with Cu and ZnO nanoparticles

Abstract

The aim of this study was to investigate coating of copper and zinc oxide nanoparticles on cotton fabric by using corona discharge in two ways of pre-treatment and post-treatment. In pre-treatment method, cotton fabrics were modified by corona discharge before coating separately with nanoparticles. In post-treatment, cotton fabrics were coated separately with ZnO and Cu nanoparticles before treating by corona discharge. Self-cleaning properties of treated fabrics were determined by staining methylene blue dye. The antibacterial tests, Scanning electron microscopy and FTIR/ATR analysis were carried out to observe antibacterial performance, surface morphology and analyze the surface chemical structure, respectively. Atomic absorption spectroscopy and water droplet adsorption were used for the determination of metal ion content, and water adsorption. Results showed that by pre-treatment method of corona discharge, absorption of copper nanoparticles was increased, and self-cleaning effect and antibacterial performance of copper nanoparticles were higher than post-treatment. ZnO nanoparticles had highest self-cleaning and antibacterial effect by pre-treatment method. By post-treatment method, the photocatalyst activity of ZnO nanoparticles was decreased.     

牡蛎肽-锌纳米粒的形成及稳定作用力

探讨牡蛎肽-锌纳米粒的形成条件及稳定作用力。通过透光率检测初步筛选牡蛎肽-锌纳米粒形成的条件,用粒径分析和电镜观察方法确认纳米粒的形成。通过次级键破坏实验分析稳定纳米颗粒空间结构的作用力。结果表明,在牡蛎肽中加入0.5%⁰.9%的硫酸锌后,将体系p H调至6.0¹1.0,即可制得粒径为28¹02 nm的牡蛎肽-锌纳米粒。锌是纳米粒的必需组分,疏水作用和静电相互作用是稳定纳米粒的关键作用力。牡蛎肽-锌纳米粒有望成为新型补锌制剂。      

纳米银海丝纤维抗菌性能和细胞毒作用的研究

 为确定纳米银海丝纤维的抗菌性能和细胞毒性作用,进行纳米银海丝纤维对金黄色葡萄菌和大肠埃希菌的定性、定量抗菌实验,采用MTT法进行了纳米银对正常人肝细胞（L-02）的细胞毒性实验以评价其使用安全性．结果显示：用0.2%以上的纳米银海丝纤维对金黄色葡萄球菌(AATCC25923)和大肠埃希菌(AATCC25922)作用4 h均产生了明显的抗菌作用,抑菌率大于75 %;纳米银颗粒对正常人肝细胞（L-02细胞）作用72 h,细胞相对增殖率（RGR）均在90.0 %以上,细胞毒性为1级,属无细胞毒性,细胞相容性好．纳米银海丝纤维具有高效抗菌活性,并且使用安全．     

Improvement properties of nylon fabric by corona pre-treatment and nano coating

This article tries to represent a supplemental method based on surface modification in order to optimizing the per cent of nano cohesion to give the better performances, such as antibacterial resistance and UV-blocking characteristic (especially in nano-ZnO), which nanoparticles carry inherently. Corona treatment was used to modify the surface of Nylon 6 fabrics in Sixdifferent conditions (related to power and passages). Treated fabrics were dyed with acidic dye and imbued with nano-ZnO simultaneously and antibacterial property, dye absorption and UV-blocking characteristic of samples were investigated. Scanning electron microscopy (SEM) was used to observe a porous Nylon fibre consisting of nano-ZnO. By increasing the power and number of passages of the corona atmosphere in which samples were contacted with, the water absorption increased. The result demonstrated that by increasing power and passages of corona treatment, dye absorption decrease likely due to the increase of the nano-ZnO cohesion. UV blocking increased in relation with increasing power and passages of corona treating. Results from antibacterial property on samples showed that by increasing the power and passages of corona treatment, the fabrics became more resistance to Staphylococcus aureus and Escherichia coli bacteria.     

家蚕丝蛋白纳米颗粒的研究进展

家蚕丝蛋白由于具有良好的物理、化学和生物学性能,以及其无毒、无害、无免疫原性,与人体有较好的组织相容性等特性,近年来在材料学、化妆护肤品、生物医学等领域有着广阔的应用前景。文中介绍家蚕丝素与丝胶蛋白纳米颗粒的制备方法及其应用,包括相分离法、乳化-溶剂蒸发法、盐析法、电喷法、电场调控法、自组装法、接枝共聚法和纳米混悬法,并指出了现研究阶段存在的问题。     

Biopolymer nanoparticles: a strategy to enhance stability,bioavailability, and biological effects of phenolic compounds as functional ingredients

Phenolic compounds are abundant in nature and have multiple beneficial effects on human health due to their antioxidant, anti-inflammatory, antithrombotic, antiallergenic, anticancer, and antiatherosclerotic properties. For this reason, phenolics are becoming relevant functional ingredients for several industries, mainly the food industry, derived from food consumer exigencies and regulations. However, the use of their beneficial properties still presents some limitations, such as chemical instability under environmental and processing conditions, which leads to structural changes and compromises their biological activities. They also present poor water solubility and sensitivity to pH changes, decreasing their bioavailability in the organism. The technologies for extraction and stabilization of these compounds have evolved rapidly in the development of different delivery systems to encapsulate sensitive active molecules. Biopolymeric nanoparticles are biodegradable polymer-based colloidal systems with sizes ranging from 1 to 1000 nm, and different techniques can be carried out to develop them. These systems have emerged as a green and effective alternative to improve stability, bioavailability, and biological effects of phenolic compounds. This comprehensive review aims to present an overview of recent advances in encapsulation processes of phenolic compounds within biopolymer nanoparticles as delivery systems and the impact on their physicochemical properties and biological effects after encapsulation. © 2021 Society of Chemical Industry.     

Anti-melanoma, tyrosinase inhibitory and anti-microbial activities of gold nanoparticles synthesized from aqueous leaf extracts of Teraxacum officinale

There has been a tenacious search for pharmaceuticals of natural origin, as they are cost-effective and are noted for having little or no side effects. The rate at which diseases are developing resistance to synthetic drugs is quite alarming, and the side effects of these drugs remain an excruciating agony to the pharmaceutical industry. Gold nanoparticles (AuNPs) have wide applications in current technology. However, their use in medicine has not been adequately explored. Chemical methods for the synthesis are associated with environmental benignity and tissue toxicity on in vivo administration. For the first time, we have synthesized AuNPs from leaf extracts of Teraxacum officinale that were found to have significant anti-melanoma, tyrosinase inhibitory and anti-microbial effects, and hence stand as promising candidates for use in cosmetics medical and food industries.     

大豆分离蛋白对大豆肽纳米颗粒Pickering乳液性能的影响

为提高大豆肽纳米颗粒(SPN)Pickering乳液稳定性,以大豆肽聚集体为原料,采用超声法制备SPN,对超声时间进行了优化;在SPN体系中引入大豆分离蛋白(SPI)构建复合乳化剂,研究不同乳化剂质量浓度下SPI对SPN界面活性和乳化稳定性的影响。结果表明：选取超声时间10 min制备SPN;随着乳化剂质量浓度的增大,乳液粒径逐渐减小,当乳化剂质量浓度较低(5 mg/mL)时,乳液出现桥联,乳化剂质量浓度过高(30 mg/mL)时则出现絮凝;界面蛋白吸附率随着乳化剂质量浓度的增加呈现先升高后降低的趋势。在相同乳化剂质量浓度下,添加SPI的SPN乳液(SPI-SPN乳液)的粒径分布峰左移,其粒径、界面蛋白吸附率显著小于SPN乳液的;在储存过程中,SPN乳液粒径逐渐增大,SPI-SPN乳液粒径没有显著变化;SPI-SPN乳液的乳析指数小于相同乳化剂质量浓度的SPN乳液,当乳化剂质量浓度为30 mg/mL时,储存15 d SPI-SPN乳液未出现分层现象。综上,SPI可以提高SPN的界面活性和SPN乳液储存过程中的絮凝稳定性和分层稳定性。     

养殖淡水鱼源ST283型B群链球菌引发食物相关侵袭性疾病风险及防控

B群链球菌存在于多种动物中,是能感染人类的一种重要条件致病菌,主要引起孕产妇及新生儿多种侵袭性疾病。ST283是近年来在东南亚地区的养殖淡水鱼中出现的一种B群链球菌型别,由于其可引起人类食物相关侵袭性疾病而受到广泛关注。我国作为淡水鱼养殖和食用大国,虽内陆尚无相关病例报道,仍需引起重视。本文就各国现有资料对ST283型B群链球菌进行阐述,为我国制定B群链球菌监测及评估标准提供参考。     

Zinc incorporation capacity of whey protein nanoparticles prepared with desolvation with ethanol

Whey protein isolate (WPI) nanoparticles were prepared using ethanol desolvation, and their capacity to incorporate ZnCl(2) was analysed. Desolvation was carried out at pH 9 and the volume of added ethanol was 0-3 times the volume of protein solution. The desolvated solutions were dispersed in acidified water (pH 3) immediately after desolvation. The size of the WPI nanoparticles increased with the volume ratio of ethanol:water used, as well as with the amount of ZnCl(2). The nanoparticles showed high incorporation efficiencies, and remained stable after 30 days of storage at 22 °C. The amount of zinc incorporated in the WPI particle suspensions was within the range of daily zinc requirements for healthy adults.     

Starch-based nanoparticles: Stimuli responsiveness,toxicity, and interactions with food components

In recent years, starch-based nanoparticles have attracted great interest due to their small size, good biocompatibility, and environmental friendliness, as well as their potential applications in foods, drug delivery carriers, and biodegradable edible films. Compared with nonstarch polysaccharides, starch can be enzymatically hydrolyzed into glucose in vivo, so it can be used as an enzyme-responsive carrier. The recent research progress of starch-based nanoparticles, including starch nanoparticles, starch nanospheres, starch micelles, starch vesicles, starch nanogels, and starch nanofibers, are reviewed in this paper. The main focus is on their responsiveness, digestibility, toxicity, interactions with other components, and applications. Starch-based nanoparticles are nontoxic and responsive to pH, temperature, light, and other stimuli. It can interact with proteins, antioxidants, and lipids through electrostatic interactions and hydrogen bonding interactions. Starch-based nanoparticles have a wide range of applications, including enhancing the mechanical properties of films and gels, stabilizing emulsions, as a fluorescent indicator, a catalyst, and a nanocarrier to control the release of active ingredients and drugs.