甲壳素/壳聚糖及其衍生物的应用情况

一、引　言　　甲壳素又名甲壳质、几丁质,是一种天然高分子聚合物,广泛存在于甲壳类动物、昆虫的外壳以及真菌的胞壁中。在自然界,甲壳素的年生物合成量约为１×１０９～１×１０１１ｔ,是仅次于纤维素的第二大生物资源,是人类取之不尽,用之不竭的巨大再生资源宝库。甲壳素属于氨基多糖,是Ｎ－乙酰基－Ｄ－氨基葡萄糖通过β－（１,４）糖苷键连接而成的直链状多糖,其分子式为（Ｃ８Ｈ１３ＮＯ５）ｎ。甲壳素经过化学修饰和改性,如水解、烷基化、磺化、硝化、卤化、羧甲基化、酰化、缩合、络合等,可获得具有特殊性质和特殊用途的…     

甲壳素和壳聚糖的制备及副产物的利用

甲壳素和壳聚糖的制备及副产物的利用蒋挺大（中国科学院生态环境研究中心，北京１０００８５）关键词：甲壳素壳聚糖制备副产物利用甲壳素（Ｃｈｉｔｉｎ）是由Ｎ—乙酰—２—氨基＿２—脱氧—Ｄ—葡萄糖以β—１、４糖苷键形式连接而成的均多糖，是自然界里存在量仅次于...     

介绍几种常用的甲壳素脱乙酰度测定方法

甲壳素是一种含氮多糖物,在自然界中贮量居第二位,甲壳素经脱乙酰基后可得壳聚糖,又称可溶性甲壳质。与甲壳素相比,壳聚糖具有许多优良性能,应用范围更广泛。实践证明,甲壳素以及由甲壳素制成的其它产品的性能与其分子量和—NH_2含量密切相关。为此,任何有关甲壳素及其提取物的理论     

甲壳素/壳聚糖的研究进展及应用

壳聚糖具有良好的生物相容性、可生物降解性、无毒、无副作用，其大分妇中所含的氨基、羟基（尤其是C6－OH）反应性质活泼，能与多种有机物发生反应；介绍了其在多个领域中的应用情况。     

关于壳聚糖制备条件的研究

本文采用正交实验法系统地研究了Na0H浓度,碱处理时间及碱处理温度这三个主要因素对制备壳聚糖的影响,并以粘度和脱乙酰度为主要性能指标,提出了一套较为合理的壳聚糖制备工艺条件。     

用丰年虫卵壳制备甲壳素和壳聚糖

介绍了用丰年虫卵壳制备甲壳素及壳聚糖的方法及过程,通过傅立叶变换红外光谱仪的检测并与美国标准谱图库检索出的用蟹壳制备的壳聚糖光谱图对照,证实丰年虫卵壳制备的壳聚糖。     

甲壳素及其衍生物壳聚糖的应用研究进展

甲壳素（chitin）又名几丁质。是自然界中含量仅次于纤维素的一种多糖，同时。也是地球上数量最大的含氮有机化合物。其在自然界中主要存在于节肢动物（主要是甲壳纲如虾、蟹等，含甲壳索高达58％～85％）、软体动物、环节动物、原生动物、腔肠动物、海藻及真菌等中，另外在动物的关节、蹄、足的坚硬部分，肌肉与骨结合处，以及低等植物中均发现有甲壳素的存在。     

南极磷虾虾壳制备甲壳素/壳聚糖的工艺研究

1　引言甲壳素又名甲壳质、几丁质等,学名为(1,4 )—2—乙酰胺—2—脱氧—β—D葡聚糖[1] ,它大量存在于节肢动物的甲壳中,也存在于低等植物的细胞壁中。壳聚糖是甲壳素的脱乙酰产物,其学名是(1,4 )—2—氨基—2—脱氧—β—D葡聚糖[1] 。甲壳素及其衍生物在农业、纺织、化工、医药、食品等领域都有广泛用途[2 ] 。甲壳素/壳聚糖原料来源丰富,目前大多以虾、蟹壳为原料进行制备[3] 。南极磷虾生活在南大洋,属甲壳动物纲磷虾目,其成体虽个体小,但生物量庞大且具有很多的生物特性,是人类可以利用的最大蛋白资源,是具有很高的开发价值的[4 ] …     

微波法制取壳聚糖

以脱乙酰度为主要性能指标,兼考虑粘度,利用微波法对几个影响壳聚糖性能的条件作比较。研究,从而提出了间歇性水洗微波法制备较高粘度、高脱乙酰度壳聚糖的工艺条件。     

甲壳素发酵液养殖草鱼、鲢鱼幼鱼试验

为研究甲壳素发酵液对草鱼和鲢鱼幼鱼养殖效果,用商品壳聚糖作参比,基础饲料为对照组,分析甲壳素发酵液对鱼体生长和水质环境等影响。试验结果表明,甲壳素发酵液处理组草鱼和鲢鱼幼鱼质量相对增长率比对照组高36.25%和122.47%(P0.05),草鱼体内脂肪酶、蛋白酶和淀粉酶3种消化酶分别比对照组高144.39%、29.53%和29.75%,鲢鱼体内消化酶比对照组高48.06%以上(P0.05)。与对照组比较,甲壳素发酵液显著降低水中亚硝态氮(61.84%)、氨态氮(30.06%)、总磷含量(52.43%),提高了草鱼对嗜水气单胞菌抗性。在试验条件下,甲壳素发酵液对草鱼和鲢鱼幼鱼起到一定的促生长作用,并能改善水质环境,甲壳素发酵液具有作为微生态制剂开发应用的潜力。     

改性壳聚糖对染料废水的脱色研究

以壳聚糖(chitosan)为原料,与卤代烷反应进行烷基化改性,用改性后的壳聚糖对酸性铬蓝K、曙红Y和亚甲基蓝的染料废水进行处理,研究了pH、投加量、时间和温度对脱色效果的影响.结果表明,在酸性较强的情况下,添加吸附剂的量有所减少,并且酸性越强,减少量越多;在一定范围内,脱色率随温度的升高而增大;随着吸附剂添加量的增加,脱色率有所提高;对3种不同染料的脱色效果为:酸性铬蓝K＞曙红Y＞亚甲基蓝;吸附过程能较好地遵循二级动力学模型和Freundlich等温方程.     

几种壳聚糖降解方法探讨

壳聚糖经降解后的低聚壳聚糖和壳寡糖具有优异的生理活性.本文着重介绍了壳聚糖降解方法中化学降解法、物理降解法和酶降解法,以及由这3种降解法派生出的一些适合实际生产的复合降解法,并对其工业化生产的可行性和品质优劣进行了探讨.     

Preparation of Water-Soluble Chitosan and its Suppressive Effect on the Denaturation of Scallop Adductor Muscle Myofibrillar Protein During Frozen Storage

ABSTRACT

In the present study, investigated were the preparation of water-soluble chitosan (WSC) by hydrolysis of original chitosan with commercial α-amylase and the suppressive effect of WSC on denaturation of bay scallop adductor muscle myofibrillar protein (Mf) during frozen storage at ?18°C for 12 months. The WSC (2.5- to 10-g dry weight) was added to 100 g of the Mf, and the changes in the Ca-ATPase activity, solubility, and sulfhydryl content were examined during frozen storage. The addition of WSC significantly reduced the denaturation of the Mf Ca-ATPase. Moreover, a significant increase in Mf solubility and sulfhydryl content was observed in the WSC-treated bay scallop adductor muscles compared with the control (p < 0.05) during frozen storage at ?18°C.     

Examination of the Interaction of Chitosan and Oil-in-Water Emulsions Under Conditions Simulating the Digestive System Using Confocal Microscopy

ABSTRACT

Chitosan is a cationic biopolymer that has been used extensively in dietary supplements to reduce fat absorption in the fight against obesity. The mechanism of fat binding of chitosan is still not fully understood and has been the subject of controversy. This study was designed to improve the understanding of the underlying mechanism by investigating the interaction of chitosan with oil-in-water emulsion droplets. Our results indicated that (0.1% w/w) chitosan adsorbed to a 20% w/w phosphatidylcholine-stabilized anionic primary emulsion to form a secondary cationic emulsion by electrostatic attraction forces under conditions resembling the stomach (pH 2). Bile salts (6 mM) were added to simulate secretion in the small intestine and pH increase. Bile salts adsorbed to the chitosan secondary emulsion, which resulted in aggregation of oil droplets followed by coalescence due to close packing of droplets. Increased viscosity (267–2531 cp) and increased degree of deacetylation (40–92% DDA) of chitosan enhanced emulsion breakdown. Increasing the pH to 7.5 without addition of bile salts yielded little aggregation. Pronounced aggregation is thought to decrease the accessibility of lipase to the oil resulting in lower bioavailability and reduced caloric intake. Understanding how chitosan interacts with oil droplets in the digestive tract is vital to developing a comprehensive model of the influence of chitosan on the bioavailability of dietary lipids. The information gained in this study may be useful for the interpretation and experimental design of animal and human feeding studies and for the rational design of chitosan-based functional foods for fat reduction.     

壳寡糖与低聚木糖对大菱鲆(Scophthalmus maximus)幼鱼生长、体组成和血液生化指标的影响

本研究以初始体重为(15.46±0.06) g的大菱鲆(Scophthalmus maximus)幼鱼为实验对象,采用2×3双因素实验设计,研究饲料中壳寡糖(Chitosan oligosaccharide,COS)和低聚木糖(Xylo-oligosaccharide,XOS)对大菱鲆幼鱼生长、体组成和血液生化指标的影响。养殖实验在全封闭循环水养殖系统中进行,养殖周期为60 d。9组实验饲料粗蛋白和粗脂肪含量分别为53%和11%;每组饲料随机投喂3桶,每桶30尾鱼。结果显示,饲料中同时添加0.5%的壳寡糖、1.0%的低聚木糖对大菱鲆幼鱼的促生长作用最明显,相对增重率显著提高。饲料中壳寡糖和低聚木糖对大菱鲆幼鱼增重率、特定生长率、饵料系数、蛋白质效率均有显著影响(P<0.05),但对大菱鲆体成分影响不显著(P>0.05);低聚木糖和壳寡糖对大菱鲆幼鱼特定生长率、增重率、全鱼粗脂肪和灰分、血清甘油三酯、溶菌酶以及碱性磷酸酶均存在显著交互作用(P<0.05)。研究表明,低聚木糖和壳寡糖配合使用可以显著提高大菱鲆幼鱼的生长效果,并且可在一定程度上增强其非特异性免疫能力,降低血脂含量。     

不同分子量壳聚糖对刺参(Apostichopus japonicus Selenka)生长和免疫功能的影响

以初始体重为(6.77±0.01)g的仿刺参(Apostichopus japonicus Selenka)为实验对象,在基础饲料中添加1％不同分子量的壳聚糖,分子量分别为35 kDa和400 kDa,进行为期56d的养殖实验,研究低分子壳聚糖(LMWC)和高分子壳聚糖(HMWC)对仿刺参生长和免疫相关酶活性的影响.结果显示,不同分子量的壳聚糖对仿刺参的生长均有促进作用,且LMWC能显著促进刺参的特定生长率(SGR)(P＜0.05).饲料中添加不同分子量壳聚糖,刺参体腔细胞中的总超氧化物歧化酶(T-SOD)活性比对照组均显著增高(P＜0.05).LMWC可显著增强刺参体腔细胞中酸性磷酸酶(ACP)活性(P＜0.05),并能提高碱性磷酸酶(AKP)和一氧化氮合酶(NOS)活性.HMWC对刺参体腔细胞中AKP和NOS活性均有显著增强作用(P＜0.05).研究表明,在刺参饲料中添加一定量的壳聚糖,对其生长和相关免疫酶活性有促进作用.     

壳聚糖固定化海洋微生物YS2071脂肪酶及其酶学性质

采用壳聚糖为载体,优化了海洋微生物YS2071脂肪酶的壳聚糖固定化条件。结果显示,在壳聚糖浓度为2% (m/v)、氢氧化钠浓度为12% (m/v)、乙酸浓度为1% (v/v)、戊二醛浓度为0.25% (v/v)、与戊二醛交联的时间为12 h及添加2 ml (1120 U)的游离脂肪酶时,固定化脂肪酶的活力最高,其活力回收率达到69.4%。对游离脂肪酶与固定化脂肪酶的酶学性质进行比较,结果显示,游离脂肪酶的最适反应温度为40℃,而固定化脂肪酶的最适反应温度为45℃,固定化脂肪酶的温度稳定性明显优于游离脂肪酶。最适反应pH均为8.0,脂肪酶经过固定化之后,酸碱耐受性增大。重复利用10次的固定化脂肪酶的酶活力保留率仍高于65%。固定化脂肪酶贮藏半衰期为96 d,而游离脂肪酶的贮藏半衰期是33 d。固定化脂肪酶与游离脂肪酶的酶活力保留率在不同有机试剂中表现出不同的稳定性。     

Effect of Chitosan Coating Enriched with 6-gingerol on Red Drum Fillets Quality and Shelf Life during Refrigerated Storage

The effect of chitosan coating enriched with 6-gingerol on the quality and shelf life of red drum fillets during refrigerated storage was investigated in this study. Samples were applied with chitosan coating (CH), 6-gingerol (GI), and chitosan coating with 6-gingerol (CH+GI) before storing at 4°C for 20 days. The data in this study showed that treatment with CH+GI could significantly decrease pH value, K-value, thiobarbituric acid value, and total volatile basic nitrogen in red drum fillets during refrigerated storage. The counts of microorganisms, such as Enterobacteriaceae, psychrotrophic, mesophilic bacteria, and lactic acid bacteria, were also significantly lower in the CH+GI group compared with those in the CH and GI groups. Moreover, the combination of chitosan coating and 6-gingerol was more effective in relieving the deterioration of tissue texture and sensory characteristics in the red drum fillets. In addition, the results suggested that chitosan coating and 6-gingerol had a synergistic effect on the quality improvement of red drum fillets. This work demonstrates that chitosan coating enriched with 6-gingerol may be a promising natural preservative for red drum during refrigerated storage.