基于铁蛋白纳米笼构建传感元件及其在食品检测中的研究进展

铁蛋白(ferritin)是由24个亚基自组装而成的中空笼形结构蛋白,具有良好的水溶性、稳定性、生物相容性和可逆自组装特性。在生物体内,铁蛋白在铁的吸收、转运、氧化和贮存中扮演重要角色,具有调节体内铁代谢平衡的功能。近年来,由于铁蛋白具有纳米尺度的笼形结构,而且容易通过化学和生物等方法进行结构改造和修饰,使得其被广泛用于检测传感元件的构建。该文对铁蛋白分子的结构与功能进行简要介绍,总结了铁蛋白在构建检测传感元件中的2种基本策略,并重点回顾了基于铁蛋白传感元件在食品真菌毒素、重金属离子、病毒、过氧化氢等有毒有害物质检测中的研究进展,以期为铁蛋白在食品检测领域的应用提供研究思路。     

铁蛋白纳米载体在营养与健康领域的应用研究进展

铁蛋白由于其良好的水溶性和生物相容性以及可逆自组装特性,已被广泛应用于各种生物活性分子的包埋递送。利用固有的肿瘤靶向性,铁蛋白纳米空腔中装载药物分子或纳米颗粒则可用于癌症的监测、诊断与治疗等。科学家们也在通过重新设计构建铁蛋白纳米笼进而拓展铁蛋白的应用范围。本文将对天然及非天然铁蛋白分子的结构特点进行总结,并对其在营养成分包埋、重金属检测和生物医药领域的应用进展进行综述。     

蛋白质纳米笼稳定Pickering 乳液及其在食品领域研究进展

Pickering 乳液是一种由固体颗粒稳定的乳液，因其良好的稳定性和生物相容性，受到了越来越多学者的关注。作为稳定Pickering 乳液的众多固体颗粒之一，蛋白质纳米笼因其独特的笼形空腔结构、良好的结构稳定性、均一的纳米尺度以及可逆自组装特性，在功能性Pickering 乳液领域展现出巨大的应用潜力。该文从稳定Pickering 乳液的固体颗粒类型、蛋白质纳米笼种类、蛋白质纳米笼稳定Pickering 乳液及其应用等方面进行阐述，总结不同类型蛋白质纳米笼的结构特点，介绍蛋白质纳米笼稳定Pickering 乳液的研究进展。基于蛋白质纳米笼的天然笼形结构优势和分子自组装特性，综述蛋白质纳米笼在多腔室乳液递送体系构建及营养成分封装递送等方面的最新研究进展。     

人体铁吸收及植物铁蛋白补铁特性研究进展

缺铁性贫血依然为全球目前所面临的公共健康营养问题之一,而铁营养作用的发挥与其吸收利用度密切相关。植物铁蛋白以其独特的笼形结构,在补铁方面拥有广阔的应用前景。该研究主要综述人体对各种来源的铁的吸收途径,以及植物铁蛋白的结构及其补铁特性。关于机体铁吸收的途径着重从血红素铁及Fe2+、Fe3+、铁蛋白等非血红素铁的角度介绍人体对不同来源铁的吸收方式,并进一步介绍影响铁吸收的因素;之后对植物铁蛋白的基本结构及其与动物铁蛋白相比之下的特殊结构进行阐述;最后针对植物铁蛋白在细胞实验、动物实验及临床研究等各方面的补铁特性以及其在纳米包埋领域的应用进行总结。该综述旨在为机体铁代谢及植物铁蛋白营养特性的深入研究奠定一定的基础。     

乳铁蛋白的结构与功能

乳铁蛋白是哺乳动物体内一种分布广、功能多的铁结合性糖蛋白,其分子组成、结构及理化特性相当复杂,使其在食品、营养、抗菌、抗病毒、增强人体免疫力、肿瘤抑制以及影响体内自由基等方面具有重要作用,成为当前的研究热点。本文概述了多年来乳铁蛋白的研究成果以及近年来的研究进展,以期促进乳铁蛋白的开发利用。     

铁蛋白铁释放机理的研究进展

铁蛋白是一种广泛存在于生命体中的铁贮藏蛋白,具有调节机体铁代谢平衡和去除二价铁毒性的双重功能。缺铁严重影响着全球近一半人的健康,研究表明,铁蛋白具有良好的补铁活性而且安全、高效,能够取代具有毒副作用的传统补铁试剂。因此,寻求并开发以铁蛋白为原料的新型补铁功能食品已成为一种趋势。为了更科学地应用于实践和开发,对铁蛋白理化性质及其生物学功能的阐明显得颇为重要。目前,关于铁蛋白铁释放机理的研究分为体外和体内两个方面,体外机理涉及还原剂和螯合剂的共同作用,而体内机理主要涉及降解途径和酶介导的还原释放途径。综述了国内外有关铁蛋白铁释放机理的研究进展,以期为新型补铁功能食品的开发提供理论依据。     

铁蛋白:一种新型矿质元素营养强化剂载体

传统的铁、钙、锌等矿质元素营养强化剂存在诸多缺点,铁蛋白因其特殊结构和功能可作为这些矿质元素营养强化剂的载体。本文通过对铁蛋白的结构和功能的阐述,以及综述其作为载体在储存铁、钙、锌等金属离子方面的研究,指出其在食品领域将具有广阔的应用前景。     

天然生物大分子及其复合物在食品微凝胶传递体系中的应用研究进展

微凝胶是一种内部交联的纳米或微米级粒子,能形成三维网络结构,可作为食品功能因子的递送载体。本文综述了适用于制作微凝胶的两大类天然生物大分子：蛋白质和多糖。介绍了常见的几种不同来源蛋白质和多糖的组成结构及胶凝特性,综述了天然生物大分子在食品传递体系中应用的最新进展,探讨其在食品微凝胶制备中的潜在价值及未来研究热点。     

漆酶在食品分子修饰和食品胶体体系中的应用

近年来,改善食品分子的功能和营养特性一直是研究的热点。食品分子的酶促修饰可用于增强其在食品中的功能性质。漆酶可催化蛋白质、多糖和多酚的氧化,在食品分子以及食品胶体的构建中具有巨大的应用潜力。文章总结了漆酶的结构、来源、对食品分子修饰的催化机制及其在食品胶体体系中的应用。研究发现漆酶分两步催化食品分子的氧化：第一步涉及产生自由基或醌的酶促反应;第二步涉及自由基或醌与其他分子的非酶促反应。漆酶在整个过程中主要起着引发反应的作用。由漆酶诱导的食品分子交联有助于改善食品分子的性质和功能,从而增加食品分子的功能性质、扩展用途,以及改善食品胶体体系(如乳液、纳米颗粒和微凝胶)的形成和稳定性,从而增强它们封装、保护和递送生物活性化合物的潜力。     

人源重链铁蛋白纯化及其纳米粒制备

为探究可逆自组装活性纳米笼形铁蛋白的成熟高效制备技术,以构建的人源重链铁蛋白(recombinant human H-chain ferritin,rHuHF)大肠杆菌原核表达系统(BL21-pET3a-rHuHF)为对象,在发酵罐内进行高效表达,并对搅拌转速、空气通量及诱导表达时间3个关键工艺参数进行优化。采用透射电子显微镜和动静态光散射仪对rHuHF的纳米结构及粒径进行表征。结果显示:搅拌转速200 r/min、空气通量1.6 L/min、表达时间9 h为最佳表达条件。经鉴定,铁蛋白存在于菌体胞内可溶物部分且具有良好的自组装活性和单分散笼形结构,9次实验中表达量最高达290 mg/L,明显高于相同条件下摇瓶培养的表达量;pH 7时rHuHF粒径为(11.23±0.10)nm,pH 2时rHuHF粒径为(2.73±0.10)nm。本实验可对铁蛋白在纳米靶向递送系统中的应用等工作提供一定的科学依据。     

超声辅助法制备铁蛋白-虾青素包埋物

虾青素是一种具有多种活性的天然类胡萝卜素,但其水溶性差,对温度和光照的敏感性高,限制了其应用。作为新型的营养物质包埋载体,铁蛋白在包埋过程中约40%会因所使用的极端pH值条件而损失。为解决上述问题,本实验通过超声辅助法,采用人重链铁蛋白对虾青素进行包埋,并通过透射电子显微镜、紫外-可见光谱、高效液相色谱对包埋物理化性质进行表征,同时通过细胞实验表征包埋物的生物活性。高效液相色谱定量分析结果表明,一个铁蛋白分子可包埋约40 个虾青素分子。光热稳定性分析结果表明,包埋入蛋白空腔后,虾青素的降解率分别由热处理终点的45%和光处理终点的31%减少至3%。铁蛋白包埋虾青素可以显著提高虾青素的水溶性和光热稳定性。本实验为营养素的包埋和载运提供了新的可能性,从而可以促进其在食品工业中的应用。     

铁蛋白铁氧化沉淀机理研究进展

铁素的缺乏严重影响着全球近一半人的健康,传统的补铁制剂由于会时人体产生副作用逐渐被禁止使用,因此,寻找安全、高效的补铁制剂势在必行.铁蛋白是广泛存在于生物体中的一种铁贮藏蛋白,它具有去除铁的毒性以及调节铁代谢平衡的双重功能.研究表明,铁蛋白具有良好的补铁活性,所以它可以作为加工原料被开发成补铁型功能食品,为此,对铁蛋白理化性质及其生物学功能的阐明就显得颇为重要.目前,有关铁蛋白的基础研究主要集中于铁蛋白的铁氧化沉淀和还原释放机理的研究,相对于后者而言,铁蛋白铁氧化沉淀机理的研究比较清楚.本文综述了国内外有关铁蛋白铁氧化沉淀机理的研究进展,以期为以后新型补铁功能食品的开发提供理论依据.     

Ferritin cage for encapsulation and delivery of bioactive nutrients: From structure,property to applications

Ferritin is a class of naturally occurring iron storage proteins, which is distributed widely in animal, plant, and bacteria. It usually consists of 24 subunits that form a hollow protein shell with high symmetry. One holoferritin molecule can store up to 4500 iron atom within its inner cavity, and it becomes apoferritin upon removal of iron from the cavity. Recently, scientists have subverted these nature functions and used reversibly self-assembled property of apoferritin cage controlled by pH for the encapsulation and delivery of bioactive nutrients or anticancer drug. In all these cases, the ferritin cages shield their cargo from the influence of external conditions and provide a controlled microenvironment. More importantly, upon encapsulation, ferritin shell greatly improved the water solubility, thermal stability, photostability, and cellular uptake activity of these small bioactive compounds. This review aims to highlight recent advances in applications of ferritin cage as a novel vehicle in the field of food science and nutrition. Future outlooks are highlighted with the aim to suggest a research line to follow for further studies.     

豌豆蛋白的改性及其在食品中应用的研究进展

豌豆是人类饮食中高品质植物蛋白的重要来源,其蛋白质成分是低致敏性的,一些学者对豌豆蛋白功能性进行了部分研究,但依然缺乏改性方法对豌豆蛋白结构和特性影响的系统报道。为了扩展豌豆蛋白在食品工业领域的应用,本文介绍了物理改性、化学改性、酶法改性和复合改性方法对豌豆蛋白结构和功能性质的影响,同时介绍了豌豆蛋白在活性成分的封装、乳液、其他蛋白的替代以及食品的优化这些方面的研究进展,并对豌豆蛋白在食品工业的应用前景上进行了展望。     

Electrospun nanofibres in agriculture and the food industry: a review

The interesting characteristics of electrospun nanofibres, such as high surface‐to‐volume ratio, nanoporosity, and high safety, make them suitable candidates for use in a variety of applications. In the recent decade, electrospun nanofibres have been applied to different potential fields such as filtration, wound dressing, drug delivery, etc. and a significant number of review papers have been published in these fields. However, the use of electrospun nanofibres in agriculture is comparatively novel and is still in its infancy. In this paper, the specific applications of electrospun nanofibres in agriculture and food science, including plant protection using pheromone‐loaded nanofibres, plant protection using encapsulation of biocontrol agents, preparation of protective clothes for farm workers, encapsulation of agrochemical materials, deoxyribonucleic acid extraction in agricultural research studies, pre‐concentration and measurement of pesticides in crops and environmental samples, preparation of nanobiosensors for pesticide detection, encapsulation of food materials, fabrication of food packaging materials, and filtration of beverage products are reviewed and discussed. This paper may help researchers develop the use of electrospun nanofibres in agriculture and food science to address some serious problems such as the intensive use of pesticides. © 2016 Society of Chemical Industry     

Impact of protein pre-treatment conditions on the iron encapsulation efficiency of whey protein cold-set gel particles

This paper investigates the possibility for iron fortification of food using protein gel particles in which iron is entrapped using cold-set gelation. The aim is to optimize the iron encapsulation efficiency of whey protein by giving the whey protein different heat treatment prior to gelation with iron. The effect of the heat treatment conditions (mild-intermediate-severe) on the iron-induced cold-set gelation process was studied to optimize the gel strength in relation to the iron concentration. Rheology was used to study the protein gel formation, and the stability of the gel particles and iron encapsulation efficiency was determined by measuring the protein and iron content at different pH. Both the iron concentration and the heat treatment conditions appear to affect the gel formation process and gel strength of the iron-induced cold-set gels. With the protein gel particles being stable at a broad pH range, the release of iron from the particles was studied as a function of time. The low release of iron at neutral pH indicated good encapsulation efficiency and capability of whey protein to keep iron bound. At low pH the release of iron increased, as is desired for bio-accessibility. In addition to differences in gel strength, the most relevant result caused by the pre-treatment of the whey protein is revealed in the amount of iron that can be entrapped per protein. It is shown that the amount of iron can be increased going from mild to severe heat treatment conditions. This suggests that the concept of using whey protein particles with iron can effectively be used to fortify food products with iron for human consumption.     

Study on iron availability from prepared soybean sprouts using an iron-deficient rat model

During soya seeds germination in FeSO₄ solutions their phytoferritin content is multiplied. Prepared soybean sprouts have been proposed as a safe and easily available source of iron supplementation. The preparation was compared with FeSO₄ and ferritin isolates, using rats with induced iron deficiency anaemia. After the end of the 2-week supplementation experiment, it was observed that no statistically significant differences in haemoglobin concentration, mean corpuscular volume, mean corpuscular haemoglobin, and mean corpuscular haemoglobin concentration existed between those animals supplemented with sprouts enriched in ferritin, ferritin isolate and FeSO₄ and healthy animals forming the control group. Moreover, the examined preparation had a beneficial influence on the recreation of ferritin reserves in both the liver and the blood serum, and also did not induce negative alterations in general growth parameters of animals. Use of an easily obtainable ferritin iron source may be a profitable alternative in supplementation due to its wide availability and food preservative properties.     

Structure,Function, and Nutrition of Phytoferritin: A Newly Functional Factor for Iron Supplement

Ferritins are members of the superfamily of iron storage and detoxification proteins present in all living organisms and play important roles in controlling cellular iron homeostasis. In contrast to animal ferritin, relatively little information is available on the structure and function of phytoferritin. Phytoferritin is observed in plastids whereas animal ferritins are largely found in the cytoplasm of cell. Compared to animal ferritin, phytoferritin exhibits two major distinctive features in structure. First, phytoferritin contains a specific extension peptide (EP) at the N-terminal while animal ferritin lacks it. The EP is located on the exterior surface of protein, which recently has been found to act as a second ferroxidase center for iron-binding and oxidation, and regulate iron release during the germination and early growth of seedlings. Second, only H-type subunit has been identified in phytoferritin, which is usually a heteropolymer consisting of two different subunits, H-1 and H-2, sharing ～80% amino acid sequence identity. These two subunits in phytoferritin play a positively cooperative role in iron oxidative deposition in protein. Iron deficiency anemia (IDA) is the most common and widespread nutritional disorder in the world, so it is crucial to explore a safe and efficient functional factor for iron supplement. Fortunately, phytoferritin seems to be a suitable candidate. In legume seeds, more than 90% of iron is stored in the form of ferritin in amyloplasts. Recently, some studies at different levels have demonstrated that plant ferritin could be used as novel, utilizable, plant-based forms of iron for populations with a low iron status. This review focuses on recent progress in structure, function, and nutrition of phytoferritin.