pH值过程控制优化低聚异麦芽糖铁配合物的制备工艺

以低聚异麦芽糖和三氯化铁为原料,以铁含量、产率和反应时间为指标,采用pH值过程控制来制备低聚异麦芽糖铁配合物,筛选出最佳的工艺条件;以粒径、Zeta电位、多分散指数、电导率来展现最佳工艺条件下反应过程的变化情况,并用红外光谱和差示扫描量热分析对最佳工艺条件下制备的产物进行表征。结果表明：当反应起始pH 12.1、反应过程pH值控制为11.5时,制得的低聚异麦芽糖铁配合物的铁含量可达43.16%,产率为96.35%,反应时间缩短为1 h,相比于未控制反应过程pH值的工艺（铁含量为37.14%,反应时间为2.7 h）,铁含量提高了16.21%,反应时间缩短了62.96%,低聚异麦芽糖与Fe3＋发生了配位反应,表明该工艺具有较高的应用价值。     

Characterization of the Supermolecular Structure of Polydatin/6‐O‐α‐Maltosyl‐β‐cyclodextrin Inclusion Complex

Polydatin is the main bioactive ingredient in many medicinal plants, such as Hu‐zhang (Polygonum cuspidatum), with many bioactivities. However, its poor aqueous solubility restricts its application in functional food. In this work, 6‐O‐α‐Maltosyl‐β‐cyclodextrin (Malt‐β‐CD), a new kind of β‐CD derivative was used to enhance the aqueous solubility and stability of polydatin by forming the inclusion complex. The phase solubility study showed that polydatin and Malt‐β‐CD could form the complex with the stoichiometric ratio of 1:1. The supermolecular structure of the polydatin/Malt‐β‐CD complex was characterized by ultraviolet–visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffractometry (XRD), thermogravimetric/differential scanning calorimetry (TG/DSC), and proton nuclear magnetic resonance (¹H‐NMR) spectroscopy. The changes of the characteristic spectral and thermal properties of polydatin suggested that polydatin could entrap inside the cavity of Malt‐β‐CD. Furthermore, to reasonably understand the complexation mode, the supermolecular structure of polydatin/Malt‐β‐CD inclusion complex was postulated by a molecular docking method based on Autodock 4.2.3. It was clearly observed that the ring B of polydatin oriented toward the narrow rim of Malt‐β‐CD with ring A and glucosyl group practically exposed to the wide rim by hydrogen bonding, which was in a good agreement with the spectral data.     

Molecular Structural Characteristics of Polysaccharide Fractions from Canarium album (Lour.) Raeusch and Their Antioxidant Activities

The objective of this study was to investigate the multiple relations between the preliminary molecular structural characteristics and antioxidant activities of polysaccharides from Canarium album (Lour.) Raeusch (CPS). Three polysaccharide fractions, CPS1, CPS2, and CPS3, were isolated from CPS by column chromatography. CPS1 and CPS3 were mainly composed of neutral polysaccharides linked by α‐ and β‐glycosidic linkages while CPS2 was pectin polysaccharides mainly linked by β‐glycosidic linkages. According to the SEC‐MALLS‐RI system, the molecular weight of CPS1 was greater compared to CPS2 and CPS3, and the molecular weight and radius of CPS did not display positive correlation. The chain conformation analysis indicated CPS1 and CPS2 were typical highly branched polysaccharides while CPS3 existed as a globular shape in aqueous. Furthermore, the antioxidant activity of CPS2 was better than that of CPS3, while that of CPS1 was the weakest. The antioxidant activities of polysaccharide fractions were affected by their monosaccharide composition, glycosidic linkage, molecular weight, and chain conformation. This functional property was a result of a combination of multiple molecular structural factors. CPS2 was the major antioxidant component of CPS and it could be exploited as a valued antioxidant product.     

Structural characterizations and digestibility of debranched high-amylose maize starch complexed with lauric acid

Structural characterizations and digestibility of debranched high-amylose maize starch complexed with lauric acid (LA) were studied. The cooked starch was debranched by using pullulanase and then complexed. Light microscopy showed that the lipids complexed starches had irregularly-shaped particles with strong birefringence. Gel-permeation chromatograms revealed that amylopectin degraded to smaller molecules during increasing debranching time, and the debranch reaction was completed at 12 h. Debranching pretreatment and prolonged debranching time (from 2 h to 24 h) could improve the formation of starch lipids complex. X-ray diffraction pattern of the amylose–lipid complexes changed from V-type to a mixture of B- and V-type polymorphs and relative crystallinity increased as the debranching time increased from 0 to 24 h. In DSC thermograms, complexes from debranched starch displayed three separated endotherms: the melting of the free lauric acid, starch–lipid complexes and retrograded amylose, respectively. The melting temperature and enthalpy changes of starch–lipid complex were gradually enhanced with the increasing of debranching time. However, no significant enthalpy changes were observed from retrograded amylose during the starch–lipid complex formation. Rapidly digestible starch (RDS) content decreased and resistant starch (RS) content increased with the increasing of debranching time, while the highest slowly digestible starch (SDS) content was founded at less debranching time of 2 h. The crystalline structures with dense aggregation of helices from amylose-LA complex and retrograded amylose could be RS, while SDS mostly consisted of imperfect packing of helices between amylopectin residue and amylose or LA.     

纺织品新型染色技术的开发与应用

对当前纺织品染色中存在的问题进行了分析,对微悬浮体染色、微胶囊染色、“色媒体”无盐无碱染色、超临界CO2染色、仿生发色及染色功能整理一体化等几种新型染色工艺和技术的原理、研究动态和应用现状进行了介绍和讨论.这些染色工艺和技术具有节约染料用量、简化工艺、节能节水、减少废液排放的特点,具有明显的生态优势.它们的推广应用将促进纺织染整行业的清洁生产和可持续发展.     

蛋白质的侧基修饰方法研究

以明胶作为皮胶原模拟物,以甲醇、二碳酸二叔丁酯((Boc)2O)作为封端剂分别封闭明胶的羧基、氨基,并用FT-IR、等电点(PI)和总碳含量(TOC)等对未改性明胶、羧基封闭明胶、氨基封闭明胶分别进行结构和性能表征。结果显示,甲醇、(Boc)2O与明胶反应后分别有酯键、酰胺键生成;羧基封闭的明胶等电点由未改性明胶的4.8上升到6.2,而氨基封闭的明胶等电点则下降到3.6;未改性明胶、羧基封闭明胶、氨基封闭明胶单位体积的总C含量分别是41.48、46.46、48.96 mg/L,羧基封闭明胶和氨基封闭明胶总有机碳含量都高于未改性明胶,表明明胶的羧基、氨基分别被封闭。     

平菇复合保鲜剂的筛选及保鲜效果

以平菇(Pleurotus ostyeatus)为实验材料,以贮藏期间的质量损失率、褐变度、呼吸强度以及感官指标(包括色泽、气味、腐烂程度、黏度等)为观测项目,采用单因素试验结合正交试验的方法研究不同质量浓度的保鲜剂柠檬酸、植酸、抗坏血酸、壳聚糖、食盐对平菇贮藏期间保鲜品质的影响。结果表明：保鲜剂质量浓度组合为柠檬酸10g/L、植酸1.5g/L、抗坏血酸1.3g/L。经此复合保鲜剂处理的平菇在(8 ± 1)℃可保存10d,其效果好于单一保鲜剂和蒸馏水对照。     

藏灵菇源酸奶复合菌发酵剂对肠道菌群平衡的作用

目的:探讨藏灵菇源酸奶复合菌发酵剂对实验性高胆固醇血症大鼠调节肠道菌群平衡的作用.方法:根据大鼠血清总胆固醇水平分组.高脂模型组和试验Ⅰ、Ⅱ组饲喂高脂饲料,对照组饲喂基础饲料;试验Ⅰ组灌胃脱脂酸奶复合菌发酵剂,试验Ⅱ组灌胃全脂酸奶复合菌发酵剂,对照组和模型组给予蒸馏水,连续8周.结果:对照组大鼠的粪便中乳杆菌、肠杆菌和产气荚膜梭菌的活菌数量处于平稳状态;4周后高脂模型组大鼠的粪便中乳杆菌的活菌数量极显著低于对照组(p＜0.01),而6周后肠杆菌和产气荚膜梭菌的活菌数量极显著高于对照组(p＜0.01);试验Ⅰ组和试验Ⅱ组大鼠粪便中乳杆菌的活菌数量分别在4周和6周开始极显著高于高脂模型组(p＜0.01),而肠杆菌和产气荚膜梭菌的活菌数量极显著低于高脂模型组(p＜0.01);试验Ⅰ组调节肠道菌群平衡效果优于试验Ⅱ组.结论:藏灵菇源酸奶复合菌发酵剂能够促进高胆固醇血症大鼠肠道有益菌的生长,并抑制有害菌的繁殖,具有明显调节肠道菌群平衡作用.