Granular structure and allomorph position in C-type Chinese yam starch granule revealed by SEM,C CP/MAS NMR and XRD

The crystalline microstructure and polymorphism of C-type starch from Chinese yam were evaluated by scanning electron microscope (SEM), ¹³C cross-polarization magic-angle spinning NMR (¹³C CP/MAS NMR) and powder X-ray diffraction (XRD) technique and acid hydrolysis method. Morphological changes during acid hydrolysis showed that the amorphous or the less crystalline areas were essentially located at the center part of C-type starch granules whereas the semi-crystalline and amorphous growth rings were found mainly in the outer part of the granules. ¹³C CP/MAS NMR and XRD results revealed that B-type allomorph was hydrolyzed more rapidly than A-type one. The amorphous or less crystalline areas were predominantly composed of B-allomorph whereas the outer semi-crystalline and amorphous growth rings were mostly composed of A-type allomorph. The A- and B-type allomorph coexisted in the individual C-type starch granule. B-type allomorph basically existed at the center part of the granules which was surrounded by the A-type allomorph in the peripheral part of granules.     

Characteristics of rennet–casein-based model processed cheese containing maize starch: Rheological properties,meltabilities and microstructures

The rheological properties, meltabilities and microstructural properties of rennet–casein-based model processed cheese slices containing normal maize starch, waxy maize starch and high amylose (70%) maize starch (HAMS) were investigated as a function of the ratio of starch to protein. The storage modulus (G′) increased with increasing ratio of normal maize starch to protein in the processed cheeses, whereas G′ decreased with the addition of waxy maize starch. The tan δ values at high temperature (90 °C) decreased with the addition of both normal maize starch and waxy maize starch, but normal maize starch caused a greater reduction in the tan δ values. These properties were influenced to a lesser extent in processed cheeses containing HAMS. Processed cheeses containing normal maize starch lost meltability at ratios of starch to protein > 0.16; waxy maize starch and HAMS had less influence on the meltability. The effect of starch on the properties of the processed cheeses was attributed to phase behaviours between the protein and the starch, which was shown in confocal laser scanning micrographs.     

阳离子淀粉絮凝剂制备及脱色性能研究

以马铃薯淀粉为原料,3～氯-2-羟丙基三甲基氯化铵为醚化剂,干法工艺制备了季铵型阳离子淀粉絮凝剂(DS=0.099),以荧光黄E-8G染料溶液模拟印染废水,研究了染料浓度、絮凝剂用量、脱色时间和废水pH对脱色率和吸附量的影响.结果表明:阳离子淀粉絮凝剂对碱性印染废水有较好的脱色能力;在废水pH为12.5,染料浓度113.5 mg/L,絮凝剂用量120 mg/L,脱色时间2 h条件下,脱色率达63.2%,吸附量为0.612 mg/mg;絮凝剂对酸性染料分子的吸附符合Langmuir单分子层吸附理论.     

辛烯基琥珀酸交联淀粉酯合成工艺研究

以木薯淀粉为原料,用环氧氯丙烷作交联剂,辛烯基琥珀酸酐作酯化剂,采用湿法工艺合成辛烯基琥珀酸交联淀粉酯.探讨了淀粉乳浓度、反应温度、反应时间、pH和沉降积对辛烯基琥珀酸交联淀粉酯取代度的影响,确定制备辛烯基琥珀酸交联淀粉酯的最佳工艺参数为:淀粉乳浓度35%,酯化pH 8.0,酯化温度35℃,酯化时间3 h.交联淀粉的沉降积对酯化取代度影响较小,在生产中可根据最终产品的用途选用合适沉降积的交联淀粉进行酯化复合变性.复合变性淀粉符合食品行业标准,可以在食品工业中应用.扫描电镜对其结构进行观察显示淀粉中受侵蚀颗粒增多,颗粒表面的小凹痕数量增加.     

机械活化对玉米乙酰化淀粉理化特性的影响

采用搅拌球磨机对玉米淀粉进行机械活化,以活化时间为60 min的玉米淀粉和原淀粉为原料制备乙酰化淀粉.研究了机械活化对玉米乙酰化淀粉理化特性影响.结果表明,机械活化预处理的玉米乙酰化淀粉的溶解度、糊透明度增大.冻融稳定性增强,凝沉性降低,糊黏度增大及其热稳定性提高.机械活化作用破坏了淀粉的结晶区,结晶程度降低,有效地改善了乙酰化淀粉的理化特性.     

淀粉黄原酸酯的合成及捕集重金属离子性能研究

以天然木薯淀粉为主要原料,环氧氯丙烷为交联荆制备交联淀粉,然后与CS2在碱性条件下发生黄原酸化反应制备改性淀粉黄原酸酯捕集荆,考察环氧氯丙烷用量、氢氧化钾用量、CS2浓度及反应温度、时间等诸因素对反应过程及产物捕集Cu2+性能的影响,确定了最佳的合成工艺条件.实验结果显示,合成捕集荆的最佳工艺务件为:环氧氯丙烷的用量为1.6 ml,KOH的用量为1.6 g.CS2用量11 ml,反应温度为35℃,反应时间为1.5 h.产物的舍硫量可达9.02%,Cu2+去除率可达96.95%.     

酸法制备玉米多孔淀粉的工艺优化及其产品特性的研究

对酸法水解玉米淀粉制备多孔淀粉进行了研究,同时采用扫描电子显微镜(SEM)和差式量热扫描仪(DSC)对所制备的多孔淀粉的颗粒结构、热学特性、成孔过程等进行分析,并将其与原玉米淀粉进行比较.其最佳工艺条件为:盐酸为10%、温度为40℃、反应时间为12 h、底物浓度为34%.用最佳工艺制备的玉米多孔淀粉,其比容积、溶解度、膨胀率、透明度和吸附能力较原玉米淀粉都有所提高,特别是吸油率增加显著.扫描电子显微镜(SEM)显示多孔淀粉表面布有凹坑或孔洞,类似蜂窝状结构,其孔径不等,密度不均;与原淀粉比较,差式量热扫描仪(DSC)表明其糊化温度范围变窄,焓变无明显变化,结晶大小均一.     

变性淀粉对烘焙果酱品质的影响

探讨了6种蜡质玉米变性淀粉对烘焙果酱保水胜、耐烘焙性、凝胶特性、外观品质和口感的影响,结果表明,两种低交联度磷酸盐交联羟丙基化蜡质玉米变性淀粉,由于其耐烘焙性较差,不宜在烘焙果酱中应用.另外两种磷酸盐交联羟丙基化蜡质玉米变性淀粉和两种己二酸交联醋酸酯化蜡质玉米变性淀粉都能显著改善烘焙果酱的耐烘焙性和持水性,赋予产品良好的组织状态和口感,其中,高交联度磷酸盐交联羟丙基化蜡质玉米变性淀粉CR3010还具有良好的热稳定性和耐酸性能,尤其适合应用于烘焙果酱中.     

提高喷墨打印性能途径浅析

从几个方面探讨了影响喷墨打印性能的因素,并进行了分析;介绍了一种新型的改性淀粉,对其应用状况进行实验分析,对比后发现其具有较高的应用性。高性价比喷墨打印纸将得到广泛的发展与应用。     

羧甲基两性淀粉的制备及应用

概述了羧甲基两性淀粉的制备理论、制备方法及影响制备的主要因素。并且通过造纸应用实验,考察了合成样品的增强作用,取得显著效果。