壳寡糖分析检测方法的研究进展

壳寡糖是由壳聚糖水解得到的一类具有生物活性的高分子化合物, 具有抗氧化、提高免疫力、抑菌、降血糖等生物学作用, 被广泛应用于食品、医药、农业、化妆品等领域。近年来随着壳寡糖应用与研究的不断深入, 壳寡糖的检测技术方法不断更新发展, 目前检测壳寡糖的方法有比色法、色谱法、质谱法以及电泳法。本文简单介绍了壳聚糖的分类, 并综述了近些年壳寡糖分析检测方法的研究进展, 以期为壳寡糖检测方法的进一步发展提供参考。     

酶法制备壳寡糖及其抗肿瘤活性评价

为进一步分析壳寡糖抗肿瘤活性及其机制,采用酶法制备工艺获取组分清晰的壳寡糖,优化酶解条件为酶解时间4 h、加酶量120 U/g,结合乙醇沉淀、超滤和纳滤联用的工艺获得聚合度2～4的壳寡糖。比较评价壳寡糖及其与阿霉素联用对3种肿瘤细胞的抑制效果,其中作用最为明显的人乳腺癌MDA-MB-231的细胞生存率降低20%。利用细胞迁移实验和激光共聚焦分析机制,得出壳寡糖可抑制MDA-MB-231细胞迁移并促进阿霉素入核。由此说明,壳寡糖可增强MDA-MB-231细胞对阿霉素的敏感性。     

Chitosan application for active bio-based films production and potential in the food industry: Review

During the past decade, there was an increasing interest to develop and use bio-based active films which are characterized by antimicrobial and antifungal activities in order to improve food preservation and to reduce the use of chemical preservatives. Biologically active bio-molecules such as chitosan and its derivatives have a significant potential in the food industry in view of contaminations associated with food products and the increasing concerns in relation with the negative environmental impact of conventional packaging materials such as plastics. Chitosan offers real potential for applications in the food industry due to its particular physico-chemical properties, short time biodegradability, biocompatibility with human tissues, antimicrobial an antifungal activities, and non-toxicity. Thus, chitosan-based films have attracted serious attention in food preservation and packaging technology. This is mainly due to a fact that chitosan exhibits high antimicrobial activity against pathogenic and spoilage micro-organisms, including fungi, and both Gram-positive and Gram-negative bacteria. The aim of the present review was to summarize the most important information on chitosan from its bioactivity point of view and to highlight various preparative methods used for chitosan-based active bio-films and their potential for applications in the food preservation and packaging technology.     

Lactose and lactose-derived oligosaccharides: More than prebiotics?

Valorization of lactose is achieved by enzymatic conversion to lactose derivatives with nutraceutical properties. This review summarizes recent developments on composition and functional properties of lactose-derived oligosaccharides. Lactose conversion by β-galactosidase yields galacto-oligosaccharides (GOS); hetero-oligosaccharides with structural and/or functional similarity to human milk oligosaccharides are synthesized by transglycosylation with β-galactosidase, sialidase, glucansucrase, fructansucrase or α-fucosidase using lactose as donor or acceptor sugar. Application development for GOS was based on their prebiotic properties; intestinal fermentation of GOS to short-chain fatty acids confers health benefits. Several novel oligosaccharides exhibit additional potent biological activities that are based on direct interaction of oligosaccharides with glycan-binding domains of bacterial adhesins and toxins, and are highly specific to the oligosaccharide structure. Particularly the use of lactose-derived oligosaccharides to prevent binding of bacterial toxins or adhesins is supported by in vivo studies.     

石莼多糖及其寡糖结构、制备及活性的研究进展

石莼多糖是石莼属海洋绿藻细胞壁的主要成分,其复杂的结构和单糖组成赋予了各种生物活性,如抗病毒、抗炎症、抗凝血、抗氧化等。但是提取得到的石莼多糖的分子量较大,存在溶解度低,生物利用率差等缺点,这很大程度地限制了石莼多糖的高值化开发与有效利用。通过降解石莼多糖得到的低分子量的寡糖产物,即石莼寡糖,不仅能够非常好地保留石莼多糖的多种生物活性,还能够有效地解决溶解度低、生物利用率差等问题。因此,石莼寡糖的制备与活性研究成为海洋生物资源开发研究领域的热点。目前,石莼寡糖主要是通过化学法,物理法和酶法三种降解方式制备得到的。该研究对石莼多糖的化学组成、结构、提取、纯化和降解制备寡糖的方法进行了综述,并对石莼寡糖的生物活性研究进展进行了总结与展望,为石莼多糖及其寡糖的研究提供理论基础并以期为海洋藻类资源的高值化开发与有效利用提供参考。     

Applications of chitosan for improvement of quality and shelf life of foods: a review

ABSTRACT:  Chitosan is a modified, natural biopolymer derived by deacetylation of chitin, a major component of the shells of crustacean. Recently, chitosan has received increased attention for its commercial applications in the biomedical, food, and chemical industries. Use of chitosan in food industry is readily seen due to its several distinctive biological activities and functional properties. The antimicrobial activity and film-forming property of chitosan make it a potential source of food preservative or coating material of natural origin. This review focuses on the applications of chitosan for improvement of quality and shelf life of various foods from agriculture, poultry, and seafood origin.     

Fabrication and characterization of exfoliated chitosan–gelatin–montmorillonite nanocomposite nanofibers

Polymeric nanofibers as one of the most known nanotechnology products have huge potential applications in many fields due to their high aspect ratio and porosity, being capable of formation of three-dimensional structures and having great mechanical and biological properties. Chitosan is a natural abundant polymer which has attracted huge interests in biomedical and biological industries due to its biocompatible, biodegradable, and non-toxicity properties. However, electrospinning of chitosan is found to be a great challenge, blending it with other polymers such as gelatin was explored as means to improve the morphological deficiencies of chitosan nanofibers and facilitate its electrospinnability. On the other hand, montmorillonite (MMT) has been attracted great attention due to its remarkable improvement in properties of polymeric composites nanofibers. The main objective of this work was on effect of concretion of gelatin–chitosan blends and MMT on morphology of resulted nanocomposite nanofibers. The x-ray diffraction data demonstrated the exfoliation of MMT layers. The morphology of electrospun chiosan–gelatin–MMT composite nanofibers was characterized using scanning electron microscope (SEM). The miscibility of blend was determined using SEM and Fourier transform infrared spectrometer/attenuated total reflectance.     

Influence of marine oligosaccharides on the response of various biological systems to UV irradiation

Low molecular weight alginate-derived oligosaccharide (ADO) (373–571 Da) and chito-oligosaccharide (COS) (855–1671 Da) were purified from alginate and chitosan, and known as marine oligosaccharides with polyanionic and polycationic properties, respectively. We compared the effects of ADO and COS on cell regulation using several biological models (Candida albicans, Escherichia coli and Bacillus subtilis spore), cellular uptake determination, erythrocytes haemolysis inhibition and antioxidant capacity assay to investigate stress response under UV radiation. Our results further confirmed the anti-UVR potential of ADO and COS and their potential for commercial UVR protector application in the area of functional foods as food ingredients.     

海洋寡糖的生物活性研究进展

寡糖是具有2～10 个单糖残基通过糖苷键连接起来的直链或含分支链的糖类化合物,对人体健康有诸多益处,还具有甜味剂功能和特性,集营养、保健、食疗于一体。相较于多糖,寡糖还具有生物活性强、利于机体吸收等优点。近年来,海洋来源的寡糖被证明具有多种生物活性,包括抗氧化、抗肿瘤、抗炎、抗菌、抗凝血和提高免疫力等,可以广泛应用于食品、医药、化妆品、农业和水产等领域。本文介绍了4 种主要的海洋寡糖,包括几丁寡糖/壳寡糖、褐藻胶寡糖、琼胶寡糖和卡拉胶寡糖,简述其来源、结构特征、各种生物活性及应用,以期为海洋多糖资源的高价值利用及海洋寡糖的深度开发提供参考。     

果胶低聚糖的研究进展

果胶低聚糖是果胶降解为较低分子质量的寡糖产物,具有低热量、促双歧杆菌生长特性以及抗肿瘤、抗氧化等生理活性,有利于人体健康,具有较大的研究意义和应用前景。本文就目前果胶低聚糖的制备方法进行分类比较,着重分析酶法制备果胶低聚糖的优点和不足;并介绍果胶低聚糖生理功能和生物活性的研究进展,旨在促进果胶低聚糖的研究和应用。     

海藻寡糖的生理活性与酶法转化研究进展

我国海藻资源极其丰富,但目前其利用主要集中于食品、饲料和保健品生产等少数方面,海藻资源的高值化利用途径有待进一步开发。海藻多糖是海藻细胞壁重要组分,具有多种生物活性功能,但因其聚合度高、黏度大、溶解性差,很难被机体吸收利用。海藻多糖经物理、化学、生物等方法可降解为海藻寡糖,其溶解性和生理学活性显著提升,更适合应用于食品、保健品、饲料、农业等诸多领域。基于酶法开发海藻寡糖绿色制备技术,具有传统方法不可比拟的优势,效率高、成本低、污染少。作者综述了褐藻寡糖、琼胶寡糖、卡拉胶寡糖、岩藻寡糖等海洋寡糖的生理活性及酶法转化的研究进展,为海藻资源的高值化利用提供新思路。     

壳寡糖功能特性研究进展

壳寡糖是一种2~10个氨基葡萄糖以β-1, 4糖苷键连接组成的碱性天然寡糖，通常由壳聚糖经化学、物理或酶法水解制备。壳寡糖具备多种重要的生物活性，如防治与代谢相关的糖尿病、高血脂症，抗肿瘤，缓解退行性疾病阿尔兹海默病、骨关节炎，提高免疫力等。已有许多研究者对其功能特性进行前期探索，获取大量有效数据，因此壳寡糖具备广阔的开发前景。本文专门对近年来壳寡糖功能特性研究及作用机理进行了论述，并分析了目前壳寡糖研究中存在的问题，以期为后续深入研究提供参考依据。     

Whey as a source of peptides with remarkable biological activities

The dairy industry generates increased amounts of whey from both cheese and casein production facilities. Whey presents an elevated content of lactose and proteins, which are associated with its high biological oxygen demand and decomposing potential. Despite its potential as pollutant, whey has been considered as a dairy by-product due to its nutritional, functional and bioactive properties. The use of enzyme technology may be an interesting strategy to convert whey into added-value products. The hydrolysis of whey proteins can generate bioactive peptides, which are described to perform physiological effects in vivo, such as antioxidant, antimicrobial, antihypertensive and antidiabetic activities. Bioactive peptides derived from whey proteins have been also associated with immunomodulatory, anticancer, opioid and hypocholesterolemic activities. This review presents a discussion on the main biological activities of peptides derived from whey proteins.     

壳寡糖复合物的制备及其功效研究进展

壳寡糖是自然界中唯一的碱性寡糖，具有-NH₂、-OH等活性基团，易溶于水，具有极高的抑菌、抗炎、抗氧化、抗癌等生物活性，能够与金属离子、蛋白质、多糖、脂类、黄酮类化合物等通过配位络合、静电相互作用、转氨法、美拉德反应及壳寡糖酰胺化、酯化、羧基化等方法形成壳寡糖复合物。壳寡糖复合物稳定性较好，水溶性高，可同时兼备壳寡糖和复合因子的生物活性的特点，有效拓宽复合物质的应用范围并增强其使用效果。此外，壳寡糖复合物的新型复合方式及安全性，是目前的一个重要研究方向。本文对近年来壳寡糖复合物的制备方法、壳寡糖复合因子及壳寡糖复合物在功能生物医药、农业、食品等领域的功效应用进行了总结，以期为壳寡糖复合物的深入研究提供参考。     

低聚糖拮抗食源性致病菌的研究及应用进展

食源性致病菌导致的食品安全问题已成为世界上重要的公共卫生问题之一,寻找高效且安全的天然抑菌剂引起人们的关注。目前有研究表明低聚糖类物质如果胶低聚糖、低聚壳聚糖、褐藻胶低聚糖等具有较好的抑菌效果,并且低聚糖大多来源于植物胶、甲壳动物,天然海藻多糖等自然物质,对环境污染较小;因此低聚糖能够作为潜在的天然抑菌剂被广泛应用在食品行业中,具有一定的研究意义和应用前景,已经逐渐成为食品行业新的研究热点。该研究综述了几种低聚糖对食源性致病菌的抑菌作用,并分析总结了其抑菌机制：一是低聚糖破坏细菌细胞壁和细胞膜,二是渗入细胞内部破坏蛋白质和核酸物质;同时展望了低聚糖在涂膜保鲜和作为食品添加剂两方面的应用,以期为进一步深入研究低聚糖的作用和在食品行业的应用提供理论参考。     

褐藻胶寡糖的制备、分离及表征研究进展

褐藻胶寡糖是通过褐藻胶降解制备得到的、由2～25个单糖(甘露糖醛酸、古洛糖醛酸)通过糖苷键结合而成的低分子聚合物.与褐藻胶相比,寡糖具有粘度低、易溶于水、易吸收、稳定性强的特点,以及食品保鲜、抗凝血、抗肿瘤、降血压血脂、促进植物生长、诱导植物产生抗性等诸多生物活性,近年来成为海洋多糖领域的研究热点.褐藻胶寡糖的纯度、性...     

褐藻胶的降解方法及其产物生物活性研究进展

褐藻胶是褐藻中含有的酸性多糖,由β-D-甘露糖醛酸及其C5差向异构体α-L-古罗糖醛酸两种单体组成。经降解后的小分子寡糖具有增强植物抗逆性、促进生长作用、抗菌活性、抗肿瘤活性、抗炎活性以及抗氧化活性等多种生理活性。目前,褐藻胶寡糖制备的方法主要有化学降解法、物理降解法和生物降解法。本文概述了褐藻胶结构、褐藻胶降解方法以及褐藻胶寡糖生理活性研究现状,其中重点介绍了生物降解的方法,并对褐藻胶裂解酶及其降解产物的应用进行了展望。     

Health promoting aspects of milk oligosaccharides

Human milk contains a large variety of oligosaccharides (HMOs) with the potential to modulate the gut flora, to affect different gastrointestinal activities and to influence inflammatory processes. Human intervention or clinical studies are still missing as the large amounts of milk oligosaccharides needed are not yet available. Therefore, there is great interest in sources of oligosaccharides other than those from human milk. Although the amount of oligosaccharides in milk of most animal species is low compared with human milk, recent data indicate significant differences among milk from farm animals. Whether some of these oligosaccharides are good candidates for human studies needs to be further investigated. Currently, there is only a limited amount of quantitative data on the total amount of oligosaccharides and on individual components in animal milk, e.g., in bovine, goat or buffalo milk. Regarding biological functions certain structural prerequisites are necessary for milk oligosaccharides to be effective in different in vitro systems. Often prebiotic oligosaccharides (PBOs) from plants are obtained by technological means and are considered to be similar or even identical to HMOs. However, there is no evidence for this speculation as PBOs are structurally quite different from HMOs. Whether PBOs exert comparable functional effects remains to be investigated. If this were the case their addition to infant formula may be useful in the context of mimicking biological functions of human milk constituents.     

海洋寡糖制备工艺及生物活性的研究进展

随着海洋多糖研究的日益广泛,人们对海洋寡糖的研究也越来越受到重视。海洋寡糖是由海洋生物多糖经不同方法降解得到的小分子聚合物,具有来源广泛、分子量小、结构独特等特点。经降解后的海洋寡糖较多糖表现出更强的生物活性,具有抗氧化活性、抗肿瘤活性、免疫调节活性、抗炎活性、调节肠道微生物及许多其他生物活性,被广泛应用于食品、保健品、医学等领域。目前,海洋寡糖的制备方法主要有化学降解法、物理降解法和酶降解法。为了让更多人了解海洋寡糖的最新研究进展,促进海洋寡糖的研究与开发,本文重点对海洋寡糖的制备方法及生物活性进行了综述,以期为海洋寡糖的深入研究与开发提供一定的参考。     

Functional properties, nutritional value, and industrial applications of Niger Oilseeds (Guizotia abyssinica Cass.)

Non-conventional seeds are being considered as novel food because their constituents have unique chemical properties and may augment the supply of nutritional and functional products. Niger (Guizotia abyssinica Cass.) seed and its crude oil have been widely used in traditional nutritional and medicinal applications. Consequently, niger seed has been extensively studied for its nutritional value, biological activities, and antioxidative properties. In consideration of their potential utilization, detailed knowledge on the composition of niger oilseeds is of major importance. The diversity of applications to which niger seed can be put gives this oilseed great industrial importance. This review summarizes the nutritional value, functional properties, and industrical applications of niger seeds.