淀粉衍生物的研究及应用

简要介绍了淀粉的结构和特点,以及物理改性、化学改性和酶法改性的基本原理,着重介绍了化学改性的基本原理,详细介绍了氧化淀粉、醚化淀粉和酯化淀粉的制备及应用,并对淀粉衍生物的研究方向作了展望,认为复合改性淀粉是未来淀粉化学品的发展趋势。淀粉衍生物可广泛应用于食品、纺织、造纸、医药等众多领域,具有广阔的发展前景。     

马铃薯淀粉基微孔炭微球的制备及其电化学性能

以存在广泛的生物质原料马铃薯淀粉为前驱体, 通过磷酸对淀粉分解的促进作用和KOH活化法制备微孔炭微球材料. 采用77 K条件下的N₂吸附、扫描电子显微镜(SEM)分别对所得样品的孔隙结构、形貌特征进行表征. 采用傅里叶变换红外(FT-IR)光谱对磷酸促进淀粉分解的机理进行研究. 在6 mol·L^-1 KOH 电解质溶液中的电化学测试表明了所得微孔炭微球材料的优异电容特性. 在50 mA·g^-1的电流密度下, 电容量为363.6 F·g^-1. 此外, 该材料表现出了优异的倍率性能, 在扫描速率为300 mV·s^-1的条件下, 所得循环伏安(CV)曲线仍能保持良好的矩形形状. 电化学测试结果表明, 马铃薯淀粉基微孔炭微球材料在高性能电化学电容器的电极材料领域具有广阔的应用前景.     

我国抗性淀粉制备工艺研究进展

抗性淀粉是指肠胃中不能被消化的那部分淀粉及其产物.由于抗性淀粉在预防Ⅱ型糖尿病、肥胖症、心脑血管疾病以及直结肠癌等方面具有特殊的功效,现已成为国际食品化学领域的研究热点之一.近年来,我国对抗性淀粉制备工艺展开了广泛的研究,取得了诸多进展.本文综述了抗性淀粉主要制备工艺的技术原理以及我国抗性淀粉制备工艺的最新研究进展,并...     

淀粉基高分子材料的研究进展

概述了近5年国内外在淀粉的化学、物理改性及其作为一种材料使用方面取得的最新研究进展.淀粉的化学改性主要介绍了淀粉的酯化、醚化、氧化、交联、接枝共聚等,而物理改性主要介绍了淀粉分别与黏土、脂肪族聚酯、聚乙烯醇以及纤维素等天然大分子的共混改性,同时还介绍了通过酸化制备淀粉纳米晶.淀粉基材料除了用于制备可生物降解塑料、吸附材...     

酯化淀粉的研究进展

对淀粉进行酯化改性可以改善淀粉的性能,从而提高其应用范围.综述了不同种类酯化淀粉的制备,包括酯化剂的种类、酯化方法,评价不同种类、取代度的酯化淀粉的性能以及应用性能,并预测了其今后的发展趋势.     

聚苯乙烯接枝淀粉纳米晶的制备

通过淀粉纳米晶与苯乙烯乳液聚合的方法制备了聚苯乙烯接枝淀粉纳米晶并用FTIR和1HNMR进行了表征;制备了不同接枝聚苯乙烯单体与淀粉纳米晶的物质的量之比(MS)的聚苯乙烯接枝淀粉纳米晶,在苯乙烯单体和淀粉纳米晶摩尔比(M/SN)为2,反应时间为5～12h条件下,所得MS为0.15～0.67.X-射线衍射结果表明,接枝聚苯乙烯几乎不会改变淀粉纳米晶的晶型,但结晶度随着MS的增加而下降.     

三氯化铝催化合成阳离子淀粉

以淀粉和三甲基环氧丙基氯化铵为原料,在三氯化铝催化作用下,制备了阳离子淀粉,最佳反应条件为:淀粉 50g,三甲基环氧丙基氯化铵 10g,三氯化铝 0. 74g, 50%乙醇 60mL,反应温度 50℃,反应时间 17h.     

微电泳法研究变性淀粉对表面活性剂的吸附作用

变性淀粉是天然淀粉经过物理、化学或酶法处理后得到的性质发生了改变的产品。经过变性,淀粉的性能得到了大大改善,广泛应用于纺织、造纸、食品、医药、卫生、油汽开采、机械铸造、建筑材料和水处理等领域[1,2]。变性淀粉的种类很多,就化学离子特性而言,就有酸解淀粉、氧化淀粉     

新型热塑性淀粉的制备和性能

以二甲基亚砜(DMSO)为增塑剂, 通过熔融共混法制备了一种新型热塑性淀粉(TPS), 研究不同增塑剂含量对材料结构和性能的影响, 并与甘油及甘油/水复合增塑淀粉体系进行了比较. FTIR结果显示, DMSO能够与淀粉产生强烈而稳定的氢键相互作用. WAXD和SEM的研究结果表明, DMSO的加入破坏了淀粉的有序结构, 实现了淀粉的塑化, 形成均一的非晶连续相. 同甘油及甘油/水增塑体系相比, DMSO与淀粉的羟基形成更为稳定的氢键, 能够有效抑制淀粉的重结晶. 动态力学和拉伸力学性能测试结果表明, 经过DMSO的增塑, 有效降低了淀粉的玻璃化转变温度, 改善了材料的韧性, 增塑效率要好于甘油及甘油/水复合增塑体系.     

淀粉和生物降解大分子间的半互穿聚合物网络的耐水性研究

以淀粉和可生物降解的PCL或PHBV等疏水性脂肪族聚酯为原料, 制备了淀粉基的Semi-IPN材料. 加入PCL或PHBV等疏水性大分子的使淀粉基Semi-IPN材料的耐水性能相对于原淀粉有很大的改善, 通过热处理和溶剂化作用能使Semi-IPN的耐水性进一步提高.     

药物控释载体醋酸酯淀粉的消化性能研究

采用生物体外(in-vitro)消化模型模拟人体消化道环境，对不同取代度的醋酸酯化木薯淀粉的消化速率进行了研究；用微生物酶对醋酸酯化木薯淀粉进行生物降解并测定各个样品的抗消化淀粉含量。结果表明醋酸酯化会增大淀粉颗粒的消化速率，但随取代度的提高消化速率呈下降趋势。同样随取代度的提高，醋酸酯化也会降低淀粉糊的消化速率。醋酸酯淀粉卡抗消化淀粉含量低于原淀粉，且取代度越高含量越低。醋酸酯化会破坏和抑制淀粉中抗消化淀粉的形成。     

Isolation, identification and characterisation of starch-interacting proteins by 2-D affinity electrophoresis

A 2-D affinity electrophoretic technique (2-DAE) has been used to isolate proteins that interact with various starch components from total barley endosperm extracts. In the first dimension, proteins are separated by native PAGE. The second-dimensional gel contains polysaccharides such as amylopectin and glycogen. The migration of starch-interacting proteins in this dimension is determined by their affinity towards a particular polysaccharide and these proteins are therefore spatially separated from the bulk of proteins in the crude extract. Four distinct proteins demonstrate significant affinity for amylopectin and have been identified as starch branching enzyme I (SBEI), starch branching enzyme IIa (SBEIIa), SBEIIb and starch phosphorylase using polyclonal antibodies and zymogram activity analysis. In the case of starch phosphorylase, a protein spot was excised from a 2-DAE polyacrylamide gel and analysed using Q-TOF MS/MS, resulting in the alignment of three internal peptide sequences with the known sequence of the wheat plastidic starch phosphorylase isoform. This assignment was confirmed by the determination of the enzyme's function using zymogram analysis. Dissociation constants (Kd) were calculated for the three enzymes at 4 degrees C and values of 0.20, 0.21 and 1.3 g/L were determined for SBEI, SBEIIa and starch phosphorylase, respectively. Starch synthase I could also be resolved from the other proteins in the presence of glycogen and its identity was confirmed using a polyclonal antibody and by activity analysis. The 2-DAE method described here is simple, though powerful, enabling protein separation from crude extracts on the basis of function.     

Determination of Damaged Starch in Wheat Flour Using an Electrochemical Bienzyme Maltose Probe

Abstract

The development of an electrochemical biosensor based on a bienzyme maltose probe and a third enzyme α-amylase in solution is reported for the rapid and inexpensive determination of damaged starch. Analytical parameters, such as probe stability, pH, temperature and response time, were optimised. Damaged starch was measured in the range of 5 × 10^?6 - 5 × 10^?4 mol/L as maltose produced by the enzymatic reaction and the detection limit was calculated according with the free maltose and/or glucose in the sample. The damaged starch was determined in different wheat flours, and the data significantly correlated with those obtained using a reference procedure (r² = 0.994; P ≤ 0.0001). In addition the results showed a comparable precision (CV < 5%). This method is rapid, inexpensive and friendly for unskilled operators.     

Thermal stability and degradation of starch derivatives

Thermal behaviour of different starch derivatives, i.e. starch esters and ethers having degree of substitution (DS) in the range of 0.02–0.18 were studied. Potato, maize and wheat starches were used. Measurements were carried out by coupled thermal analysis/ mass spectrometry method (STA-MS) in air atmosphere. The major DTG peak during the investigation for starch derivatives is observed below 300°C. The mass loss up to a temperature of 300°C is about 50%. The most abundant ions found areH₂O⁺ and CO₂ ⁺. For the studied starch derivatives with a low degree of substitution (DS<0.18) no correlation was found between thermal stability and the level of substitution regardless of the nature of substitution.     

Ultrasonic study of adsorption in polysaccharide (starch) metabolism

Starch metabolism due to adsorption of enzyme amylase on the starch substrate is outlined briefly. To explore the necessary conditions required for effective adsorption in biological media, ultrasonic techniques have been applied to elucidate the structural variations and component destruction in the considered systems. The ability of the enzyme amylase to break the linkages in starch (substrate) was determined from the observed ultrasonic velocity, which highlights the deciding factors of metabolism. It is concluded that the phenomenon of adsorption is decided by the surface area, the number of subunits held by the substrate, and the structure existing in the adsorbent, and above all, a relatively higher quantity of enzyme and the substrate.     

Starch Granule Size and Morphology of Arabidopsis thaliana Starch-Related Mutants Analyzed during Diurnal Rhythm and Development

Transitory starch plays a central role in the life cycle of plants. Many aspects of this important metabolism remain unknown; however, starch granules provide insight into this persistent metabolic process. Therefore, monitoring alterations in starch granules with high temporal resolution provides one significant avenue to improve understanding. Here, a previously established method that combines LCSM and safranin-O staining for in vivo imaging of transitory starch granules in leaves of Arabidopsis thaliana was employed to demonstrate, for the first time, the alterations in starch granule size and morphology that occur both throughout the day and during leaf aging. Several starch-related mutants were included, which revealed differences among the generated granules. In ptst2 and sex1-8, the starch granules in old leaves were much larger than those in young leaves; however, the typical flattened discoid morphology was maintained. In ss4 and dpe2/phs1/ss4, the morphology of starch granules in young leaves was altered, with a more rounded shape observed. With leaf development, the starch granules became spherical exclusively in dpe2/phs1/ss4. Thus, the presented data provide new insights to contribute to the understanding of starch granule morphogenesis.     

Production of Cyclodextrins by CGTase from Bacillus clausii Using Different Starches as Substrates

Cyclodextrins (CDs) are cyclic oligasaccharides composed by d-glucose monomers joined by α-1,4-d glicosidic linkages. The main types of CDs are α-, β- and γ-CDs consisting of cycles of six, seven, and eight glucose monomers, respectively. Their ability to form inclusion complexes is the most important characteristic, allowing their wide industrial application. The physical property of the CD-complexed compound can be altered to improve stability, volatility, solubility, or bio-availability. The cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) is an enzyme capable of converting starch into CD molecules. In this work, the CGTase produced by Bacillus clausii strain E16 was used to produce CD from maltodextrin and different starches (commercial soluble starch, corn, cassava, sweet potato, and waxy corn starches) as substrates. It was observed that the substrate sources influence the kind of CD obtained and that this CGTase displays a β-CGTase action, presenting a better conversion of soluble starch at 1.0%, of which 80% was converted in CDs. The ratio of total CD produced was 0:0.89:0.11 for α/β/γ. It was also observed that root and tuber starches were more accessible to CGTase action than seed starch under the studied conditions.     

乙酰化淀粉的塑化和性能研究

以乙酰化改性淀粉为基体,甘油为增塑剂,利用哈克旋转流变仪密炼制备热塑性乙酰化淀粉.实验结果表明制备热塑性乙酰化淀粉的甘油/乙酰化淀粉配比应大于30/100(W/W),且随甘油含量增加,热塑性乙酰化淀粉的脆性降低.动态机械热分析(DMTA)显示热塑性乙酰化淀粉包含富甘油和富淀粉两相,乙酰化淀粉和甘油为部分互溶.流变学分析显示淀粉分子间作用力非常强,表现为类固态行为.同时本文对材料的热稳定性进行了初步研究.     

ICP-OES测定醋酸酯淀粉中10种元素含量

醋酸酯淀粉样品经微波消解后,采用电感耦合等离子体发射光谱（ICP-OES）法测定其中钾、钙、钠、镁、铜、铁、锌、锰、磷、镍等10种元素含量.方法线性范围宽,线性相关系数r大于0.999 4,回收率为90.0%~106.7%,RSD小于3.9%.方法具有操作简单、快速、准确、可靠等优点,在醋酸酯淀粉分析中,取得了令人满意的结果.检测结果表明：醋酸酯淀粉中含有丰富的钙元素,磷、钾、钠元素含量较丰富,含有微量的镁、铜、铁、锰、镍等元素.     

Mechanical properties and enzymic degradation of thermoplastic and granular sago starch filled poly(ε-caprolactone)

The mechanical, morphological and biodegradation properties of two types of poly(ε-caprolactone)/sago starch (PCL/sago) composites were investigated i.e. dried granulated sago starch and undried thermoplastic sago starch (TPSS). Thermoplastic starch was extruded with a twin screw extruder model Haake Rheomix (TW100 attached to a Haake Rheometer (Haake Rheodrive 5000). The composites were compounded with a Haake internal mixer (Haake Rheomix 3000) attached to the Haake Rheometer. Tensile properties were determined with the Monsanto Tensometer T10. A Shimadzu UV-160A visible UV spectrophotometer was used to monitor the liberation of carbohydrate as a consequence of starch hydrolysis by α-glucoamylase. Determining the weight loss of composites as well as the acid liberated from PCL also monitored biodegradation. The results indicate that dried granulated sago starch function better as fillers in terms of mechanical properties and the ease of biodegradation. However, TPSS imparted better yield strength to the composites. Poor wetting of starch accounts for the decreased mechanical properties at higher starch concentration as agglomeration occurs. While the rigid granular starch retained their shape in the composites, thermoplastic starch that is surrounded by microvoids is easily deformed due to plasticization.