Studies on chitin 3—effect of coagulants and annealing on the preparation and the properties of chitin membrane

Chitin membrane was prepared by casting a N,N-dimethyl acetamide, N-methyl 2-pyrrolidone and lithium chloride (DMA-NMP-LiCl)solution of chitin and coagulating with several media. The effect of the coagulants on membrane formation was studied. 2-Propanol was found to be more favourable than methanol, ethanol, acetone and mixtures of 2-propanol and water. The membrane obtained in 2-propanol was subjected to annealing. Annealing made the membrane dense and strong. The tensile strength of the membrane annealed at 145°C for 2hr was about twice that of an unannealed membrane. The solute permeability of the annealed membranes was lower than that of the original one. These phenomena could be clearly interpreted in terms of crystallinity.     

甲壳素纤维/毛/绒双层织物的设计

通过分析甲壳素纤维各项性能,将其引入山羊绒产品中,对双层织物的设计进行探讨,并经过纺纱和织物试制,提出了设计与生产中应注意的问题,开发出了具有永久抗菌性的表层为羊绒、里层为甲壳素与改性羊毛混纺的系列产品.     

18.2tex桑皮纤维/粘胶基甲壳素纤维混纺纱的开发

介绍了18.2tex桑皮纤维/粘胶基甲壳素纤维50/50混纺保健纱开发的工艺要点。通过分析桑皮纤维和粘胶基甲壳素纤维的物理性能特点,选择适当的纤维混合方案,并制定了纺纱工艺流程,进行了工艺参数的设计和优选,纱线具有护肤、抗菌等保健功效。     

甲壳素脱乙酰酶的研究进展

甲壳素脱乙酰酶(CDA)是一种可以将甲壳素转化为壳聚糖的酶类,而壳聚糖在食品、医药、化工等领域有着广泛的应用,它的生物制备技术是目前国际关注的焦点问题。就CDA的产生菌、酶的作用机理、酶的生物学功能等方面进行了综述,并对CDA潜在的应用价值进行了展望。     

Preparation and characteristics of squid pen β‐chitin prepared under optimal deproteinisation and demineralisation condition

Squid (Todarodes pacifica) pen was an excellent source of β‐chitin with 25.5% yield. The optimal condition to prepare squid pen β‐chitin was established: deproteinisation with 3% NaOH for 30 min at 15 psi/121 °C and a solid/solvent ratio of 1:10 (w/v) and a subsequent demineralisation with 1 N HCl for 30 min at room temperature and a solid/solvent ratio of 1:10 (w/v). Squid pen β‐chitin contained 6.29% nitrogen, 0.25% ash, and negligible fat with degree of acetylation of 94.02%, residual amino acid of 0.499 g/100 g and bulk density of 0.28 g mL^?1. Depending on its particle size, squid pen β‐chitin visually looked white (L* = 82.82, a* = ?0.67, b* = 6.31; particle size of 0.15–0.18 mm) or light grey (L* = 62.88, a* = 0.33, b* = 10.66; particle size of 0.425–0.841 mm). Water, fat and dye‐binding capacity of squid pen β‐chitin was 694.67%, 194.03% and 79.81%, respectively.     

从虾蛄壳制备甲壳素和壳聚糖的研究

以虾壳和虾蛄壳为原料分别采用EDTA法和盐酸法制备了甲壳素和壳聚糖。采用红外光谱和化学分析方法分析了甲壳素和壳聚糖试样的结构和主要性能指标，其结果为：虾蛄壳是一种优良的制备甲壳素、壳聚糖的原料，尤其是可制得相对分子质量较高的甲壳素和壳聚糖。     

甲壳素及其衍生物在造纸工业中的应用

甲壳素是地球上的第二大可再生资源。主要论述了甲壳素及其衍生物的制备、结构和性质，并讨论了其在造纸工业中的应用。     

超细甲壳素脱乙酰制备水溶性壳聚糖的研究

在45%氢氧化钠溶液中,反应温度不高于80℃时可以直接以超细粉碎的甲壳素为原料脱乙酰制备能溶于水的壳聚糖,测定其脱乙酰度约为50%,XRD表明其内部结构呈非晶态。     

蝇蛆壳聚糖制备工艺的研究

研究了蝇蛆甲壳素的脱乙酰反应过程,确定了制备蝇蛆壳聚糖的最佳反应条件:反应温度90℃、NaOH溶液的浓度为50%、反应总时间6h、间歇处理2次、每次处理时间为3h。     

Dietary Fibre Content and Composition of Some Edible Fungi Determined by Two Methods of Analysis

Six common edible fungi from four orders of Basidiomycetes, namely Agaricus bisporus (Agaricales), Auricularia auricula and Auricularia polytricha (Auriculariales), Tremella fuciformis (Tremellates), Ganoderma lucidum and Poria cocos (Aphyllophorales), were analysed for their total dietary fibre (TDF) content using the Association of Official Analytical Chemists (AOAC) method and for dietary fibre content and composition using the Uppsala method. The non-protein nitrogen contributed from fungal chitin was corrected in the fibre residue obtained by the AOAC method. The TDF content measured by the AOAC method was always greater than that of the Uppsala method. The TDF content determined by the AOAC and Uppsala methods ranged from 182 and 132 g kg^-1 (dry matter) in A bisporus to 735 and 711 g kg^-1 (dry matter) in P cocos, respectively. Neutral and amino sugars were the dominant sugars in all the fungi. Sugar composition of the TDF reflected that the major cell wall polysaccharides in most fungi were hemicelluloses, such as β-glucan and glucuronoxylomannan, pectic substances and chitin. Judging from their high fibre content and unique fibre composition, edible fungi have considerable value as sources of dietary fibre in human nutrition. © 1997 SCI.