壳聚糖及衍生物在食品保鲜防腐中的应用

壳聚糖及衍生物具有无毒、价廉、可生物降解、良好的成膜性和强的抗菌保鲜防腐能力,因而受到了国内外的广泛研究。本文综述了以壳聚糖及衍生物在三大食品工业——饮料、水果、肉类中的应用,并对壳聚糖及衍生物的防腐保鲜前景进行了展望。     

壳聚糖复合物对重金属离子的吸附作用

壳聚糖复合物是壳聚糖与其它无机、有机物质经物理或化学方法合成的复合吸附剂。复合后改善了吸附剂的物理性能,提高了吸附能力,增加重复使用次数。因此壳聚糖复合物在工业废水处理领域得到广泛的应用。本文综述了不同壳聚糖复合物对重金属离子的吸附作用,对壳聚糖复合物的研究方向进行了展望。     

壳聚糖-分子筛复合物选择性吸附卷烟烟气中挥发性羰基化合物的应用研究

制备了壳聚糖-分子筛复合物,并使用扫描电镜观测了复合物的微观形态.研究了分别添加壳聚糖-分子筛复合物、4A分子筛及壳聚糖等材料的卷烟复合滤咀对主流烟气中低分子醛酮类化合物的吸附效果.研究结果表明,添加了壳聚糖-分子筛复合物、4A分子筛及壳聚糖的卷烟滤咀对主流烟气中低分子醛酮类化合物均有较好的吸附作用.且对焦油、烟碱量无明显影响;壳聚糖-分子筛复合物(添加量为2.4 mg·mm-1)对主流烟气中醛酮类化合物的吸附能力优于其它2种材料,该复合物对一氧化碳有一定的吸附,且对抽吸品质有改善,口感柔和,烟气刺激性降低.     

壳聚糖-活性炭复合物吸附性能及抑菌性能研究

将壳聚糖(CTS)与活性炭(AC)制成壳聚糖-活性炭复合物(CTS-AC)。考察了壳聚糖用量、制备复合物的pH以及沉淀剂对复合物吸附性能的影响;进而研究了复合物对大肠杆菌和金黄色葡萄球菌的抑制效果。结果表明,随着复合物中壳聚糖含量的升高,复合物的吸附性能下降,但抑菌效果增强;随着制备复合物的pH的升高,复合物的吸附性能增强;以NaOH-乙醇为沉淀剂时,复合物的吸附性能最佳,但抑菌效果最差。     

聚乙烯醇对淀粉/壳聚糖草酸盐复合物及其膜性能的影响

制备了不同含量聚乙烯醇的淀粉/壳聚糖草酸盐复合物及其膜,研究了其溶液的黏度-时间关系、失水率、粒度分布、红外光谱谱图和DSC曲线。结果表明:聚乙烯醇的添加,提高了淀粉/壳聚糖草酸盐复合物的黏度,聚乙烯醇含量越高,其黏度增加的趋势越大;聚乙烯醇含量达到一定程度时,可以提高淀粉/壳聚糖草酸盐复合物失水率;复合物粒径分布范围随聚乙烯醇含量的增加而变窄;红外谱图表明聚乙烯醇与淀粉/壳聚糖草酸盐复合物通过氢键等缔合形成了新结构;DSC表明聚乙烯醇对淀粉/壳聚糖草酸盐复合物膜的热稳定性有一定影响,但仍具有良好的相容性。     

酯化大豆蛋白-壳聚糖复合物乳化性及抑菌性

以酯化大豆蛋白和壳聚糖为原料，按照酯化大豆蛋白与壳聚糖质量比为1∶0.1，将酯化大豆蛋白与壳聚糖溶液混合并常温搅拌3 h，制得酯化大豆蛋白-壳聚糖复合物。探讨了pH 5.0下酯化大豆蛋白-壳聚糖复合物的功能性质。采用红外光谱和荧光光谱研究了酯化大豆蛋白-壳聚糖复合物的结构，探讨了酯化改性协同壳聚糖复合改性对复合物乳化性和抑菌性的影响。结果表明，氢键参与了酯化大豆蛋白-壳聚糖复合物的形成过程；在pH 5.0下，相较于酯化大豆蛋白，酯化大豆分离蛋白-壳聚糖复合物（MSPI-CS）、酯化大豆球蛋白-壳聚糖复合物（M11S-CS）、酯化β-伴大豆球蛋白-壳聚糖复合物（M7S-CS）的乳化活性分别提升至10.8 m2/g、9.0 m2/g、12.0 m2/g，乳化稳定性分别提升至88.9 min、71.4 min、95.4 min；MSPI-CS、M11S-CS、M7S-CS对大肠杆菌、金黄葡萄球菌和沙门氏菌的抑菌圈直径均增加；以MSPI-CS、M11S-CS、M7S-CS为乳化剂制备乳液，乳液的平均粒径降低至255.2 nm、315.6 nm、253.6 nm，Zeta-电位绝对值提升至22.07 mV、20.68 mV、22.33 mV，同时乳液存储稳定性提高。     

壳聚糖季铵盐及其复合物的研究进展

壳聚糖季铵盐及其复合物是一种很有应用前景的材料,作者综述了壳聚糖季铵盐及其复合物在载基因、载药、抗菌创伤材料、抗凝血材料、水处理材料等领域的研究进展。     

壳聚糖的成膜性及其在食品保鲜、包装上的应用

综述了壳聚糖成膜性的影响因素,壳聚糖膜在果蔬保鲜、食品保鲜及可食性包装膜方面的应用研究进展。     

以纳米金-壳聚糖为固定化载体的酶放大压电免疫传感器的研究

采用原位合成法制备了具有良好生物相容性的无机-有机纳米复合物纳米金-壳聚糖,经紫外可见吸收光谱和透射电镜检测表明,该复合物中纳米金具有良好的分散性.以检测人IgG为例,对该复合物作为抗体固定化载体的性能进行了研究,发现与采用半胱胺自组装膜的传感器比较,纳米金-壳聚糖复合膜可固载更多的抗体,传感器具有更大的频率响应.实验设计的传感器可在10～150 ng·mL-1范围内定量检测人IgG.     

壳聚糖及其衍生物的保鲜功能应用进展

壳聚糖是一种丰富的天然氨基多糖,来源丰富,因其独特的结构而具有许多独特的物理化学特性和生物功能.介绍了壳聚糖及其衍生物的特性、在果蔬以及鲜切花保鲜方面的原理,综述了壳聚糖及其衍生物在保鲜方面的功能和应用研究.     

壳聚糖及其衍生物在食品工农业中的应用研究进展

壳聚糖作为一种天然碱性多糖,具有高附加值、可再生资源、抑菌、无毒、易成膜、可生物降解、螯合重金属等优点。文章综述了壳聚糖在食品工农业方面的应用研究进展情况,详细介绍了壳聚糖、改性壳聚糖和复合壳聚糖在果蔬保鲜、植物诱导、防止微生物生长、果汁澄清、添加剂和食品工业废水方面的应用性能,并对壳聚糖在食品中应用的未来发展进行展望。     

Metal recovery using chitosan

Chitosan is a natural polycationic polymer which possesses valuable properties as a metal recovering and water purifying agent. Applications are —waste water treatment for heavy metal and radio isotope removal and valuable metal recovery, —potable water purification for reduction of unwanted metals, —agriculture—controlled release of trace metals essential to plant growth, —food—complex binding of iron in precooked food to reduce ‘warmed-over flavour’. The interactions of metals with chitosan are complex, probably simultaneously dominated by adsorption, ion-exchange and chelation. To study this it is of utmost importance to work with well characterized chitosans. This has been a problem as available characterizing methodology is limited. Degree of polymerization and deacetylation and the distribution of acetyl groups along the polymer chain is of crucial importance for chitosan metal interacting characteristics. Making chemical derivatives is a way to alter the metal interacting characteristics of chitosan. Chitosan possesses general coagulant/flocculant characteristics towards bio-molecules and surfaces.     

低聚壳聚糖的复合酶法制备研究

通过对黏均分子量、酶活力、水解率和还原糖浓度的测定,研究了由商业α-淀粉酶、纤维素酶和果胶酶1∶1∶1(m/m/m)组成的复合酶降解壳聚糖的最佳工艺条件,结果表明:复合酶在酶底物比为1∶5(m/m)、pH 5.3、温度56℃的条件下,酶解2 h可得到分子量为1 000～4 000的低聚壳聚糖,且通过傅里叶红外光谱分析酶解后的产物结构无明显变化。     

壳聚糖schiff碱的应用进展

介绍了壳聚糖的特性,制壳聚糖schiff碱的方法,叙述了壳聚糖schiff碱的催化性能和在环保、食品、医药、化妆品等方面的应用。认为应对较复杂的含杂环的醛、酮改性制备schiff碱及其在应用领域如医药的抗菌抗癌作用等作深入地研究。     

基于壳聚糖纳米粒子载药体系的制备与应用研究进展

壳聚糖纳米粒子载药体系因其天然无毒、生物相容性高、可生物降解等特点,在生物医学、化工和食品等领域有广阔的应用前景。本文对制备壳聚糖纳米粒子的离子交联法、聚电解质复合法、乳化交联法、喷雾干燥法和溶剂蒸发法等主要方法进行了综述,并阐述了其制备原理和优缺点。此外,本文结合国内外学者近期的研究工作,综述了壳聚糖纳米粒子载药体系在抗肿瘤药物和抑菌药物方面的应用研究进展,并对壳聚糖装载降糖药物、降脂药物、治疗骨质疏松药物和抗癫痫药物应用进行了简介。最后结合壳聚糖纳米载药体系在制备方法及应用中存在的实际问题,提出多学科研究相结合,开发壳聚糖纳米载药体系的智能控释、靶向递送功能和突破人体特殊生物屏障功能将是其近期的重点研究方向。     

壳聚糖及其衍生物的絮凝作用的应用

介绍了壳聚糖及其衍生物的絮凝作用在各领域的应用。     

Selected Applications of Chitosan Composites

Chitosan is one of the emerging materials for various applications. The most intensive studies have focused on its use as a biomaterial and for biomedical, cosmetic, and packaging systems. The research on biodegradable food packaging systems over conventional non-biodegradable packaging systems has gained much importance in the last decade. The deacetylation of chitin, a polysaccharide mainly obtained from crustaceans and shrimp shells, yields chitosan. The deacetylation process of chitin leads to the generation of primary amino groups. The functional activity of chitosan is generally owed to this amino group, which imparts inherent antioxidant and antimicrobial activity to the chitosan. Further, since chitosan is a naturally derived polymer, it is biodegradable and safe for human consumption. Food-focused researchers are exploiting the properties of chitosan to develop biodegradable food packaging systems. However, the properties of packaging systems using chitosan can be improved by adding different additives or blending chitosan with other polymers. In this review, we report on the different properties of chitosan that make it suitable for food packaging applications, various methods to develop chitosan-based packaging films, and finally, the applications of chitosan in developing multifunctional food packaging materials. Here we present a short overview of the chitosan-based nanocomposites, beginning with principal properties, selected preparation techniques, and finally, selected current research.     

Chitinous polymers: extraction from fungal sources,characterization and processing towards value-added applications

Chitin, chitosan and their complexes with β-glucan (chitin–glucan complex, CGC, and chitosan–glucan complex, ChGC) are value-added polysaccharides extracted from the cell-walls of many fungi. Commercial chitin and its deacetylated form, chitosan, are currently obtained from marine waste material, mostly animal sources (crustaceans and marine invertebrates), through harsh chemical procedures that have low reproducibility due to the variability of the composition of the sources and their seasonal character. These disadvantages are overcome by using fungi as sources of chitinous polymers. The extraction of chitin/chitosan from fungi cell-walls has the great advantage of yielding products with stable composition and properties, using simpler procedures, with the added benefit of also generating CGC and ChGC, two copolymers that combine the proven properties of chitin/chitosan with those of β-glucans. Over the last decades, fungal chitinous polymers have been the focus of extensive research that included optimization of the cultivation conditions of a wide range of species and the development of optimized extraction, purification and characterization techniques, as well as the demonstration of the biopolymers' biological properties, which include immunomodulatory, anticancer, antioxidant and antimicrobial activity. Given these properties, several attempts were made to develop applications for them in areas ranging from biomedicine and pharmaceuticals to food and agriculture. Despite their wide range of proven functional properties that include the ability to form different polymeric structures, as well as biological activity, fungal chitinous biopolymers are still underexplored. Nevertheless, these biopolymers hold great potential for development into valuable products or applications that are surely worth further investigation. © 2019 Society of Chemical Industry     

Factors Influencing the Antibacterial Activity of Chitosan and Chitosan Modified by Functionalization

The biomedical and therapeutic importance of chitosan and chitosan derivatives is the subject of interdisciplinary research. In this analysis, we intended to consolidate some of the recent discoveries regarding the potential of chitosan and its derivatives to be used for biomedical and other purposes. Why chitosan? Because chitosan is a natural biopolymer that can be obtained from one of the most abundant polysaccharides in nature, which is chitin. Compared to other biopolymers, chitosan presents some advantages, such as accessibility, biocompatibility, biodegradability, and no toxicity, expressing significant antibacterial potential. In addition, through chemical processes, a high number of chitosan derivatives can be obtained with many possibilities for use. The presence of several types of functional groups in the structure of the polymer and the fact that it has cationic properties are determinant for the increased reactive properties of chitosan. We analyzed the intrinsic properties of chitosan in relation to its source: the molecular mass, the degree of deacetylation, and polymerization. We also studied the most important extrinsic factors responsible for different properties of chitosan, such as the type of bacteria on which chitosan is active. In addition, some chitosan derivatives obtained by functionalization and some complexes formed by chitosan with various metallic ions were studied. The present research can be extended in order to analyze many other factors than those mentioned. Further in this paper were discussed the most important factors that influence the antibacterial effect of chitosan and its derivatives. The aim was to demonstrate that the bactericidal effect of chitosan depends on a number of very complex factors, their knowledge being essential to explain the role of each of them for the bactericidal activity of this biopolymer.     

甲壳素及壳聚糖的应用

介绍了甲壳素及壳聚糖的性质,概述了近年来甲壳素及壳聚糖在生物工程、化工环保、生物医学、食品工业等领域的应用进展。