低粘度阳离子淀粉的制备及其性能研究

以木薯淀粉为原料,3-氯-2-羟丙基三甲基氯化铵为阳离子醚化剂,以双氧水、次氯酸钠为氧化剂,采用微波辅助法制备低粘度阳离子淀粉。研究探讨氧化剂品种、用量及氧化剂的协同应用对阳离子淀粉糊液粘度及稳定性的影响,并对工艺参数进行优化验证。结果表明,双氧水、次氯酸钠的协同应用对阳离子淀粉进行氧化,能获得具有更低粘度和更高糊液稳定性的低粘度阳离子淀粉。     

高浓低黏高稳定性阳离子表面施胶淀粉的研制

以木薯淀粉为原料,采用低黏度化与阳离子化同时进行,然后用复合氧化相结合的方法研制高浓低黏高稳定性阳离子表面施胶淀粉.探讨了活化降黏剂用量、氧化剂A用量、氧化剂B用量、醚化降黏反应温度、醚化降黏反应时间等对阳离子表面施胶淀粉黏度及电位的影响.结果显示:在水介质中,阳离子醚化剂用量2.5%,活化降黏剂用量0.8%,醚化反应温度48℃,醚化反应时间5h,氧化剂A用量0.6%-0.8%,一次氧化反应温度42℃,一次氧化反应时间2h,氧化剂B用量1.0%～1.5%,二次氧化反应温度36℃,二次氧化反应时间2h,得到的阳离子淀粉糊液黏度低、稳定性高,能满足高浓度表面施胶的需要.     

黄原胶对木薯阴阳离子淀粉糊性质的影响

本文采用Brabender黏度计和哈克流变仪研究了黄原胶对木薯阴、阳离子淀粉糊黏度、冻融稳定性及流变学性质的影响。结果表明:黄原胶使木薯阴、阳离子淀粉糊的峰值黏度和崩解值均显著增加,但其起始糊化温度有所降低;添加黄原胶后,阳离子淀粉的析水率有了一定程度的提高,冻融稳定性减弱,而阴离子淀粉的析水率下降;黄原胶的加入使两种变性淀粉凝胶的tanα值降低,储能模量(G’)增大,这使得木薯阴阳离子淀粉凝胶向趋于固性的方向发展。      

微波辐射对阳离子淀粉性质的影响

为了改善阳离子淀粉的性质,采用微波辐射与半干法结合工艺制备阳离子淀粉,比较微波半干法及半干法两种工艺制备的阳离子淀粉的分子结构及糊液性质的差异。结果显示：相比半干法工艺,微波半干法对阳离子支链淀粉的降解作用更明显。电子显微镜图片显示,半干法阳离子淀粉颗粒形态未发生明显变化,仅表面变得粗糙、破裂,而微波半干法阳离子淀粉颗粒出现了变形和凹坑。微波半干法阳离子淀粉较半干法样品的溶解度、透光率和冻融稳定性提高,峰值黏度及终黏度降低。     

氧化程度对羧酸型两性淀粉性能的影响

氧化型两性淀粉是一种新型的两性淀粉,同时包含羧基和阳离子基团。其制备采用两步法,先将淀粉阳离子化,再将阳离子淀粉氧化。阳离子淀粉最佳制备工艺为:淀粉乳浓度35%,醚化剂的用量为5%,pH11.6,反应先在50℃活化2h,再降温到45℃反应8h。通过添加不同量的NaClO到阳离子淀粉中制得羧基含量不同的两性淀粉,所得淀粉洁白,糊透明度高,稳定性强,凝沉性弱,热糊粘度也较阳离子淀粉明显下降,且这些性能均随羧基含量的增加而增强。     

阳离子淀粉乳化性能的研究

采用半干法合成阳离子淀粉。重点研究阳离子淀粉在大豆油与水乳液体系中的乳化性及乳液稳定性。考察了取代度、阳离子淀粉的质量分数、油水比等条件对阳离子淀粉乳化性及其乳化稳定性的影响。结果表明:在取代度0.145时,阳离子淀粉的乳化性及乳液的稳定性均较好;阳离子淀粉质量分数为2%时,乳液的颗粒均匀大小一致,乳化效果较好;当油水体积比为4:6时,乳液呈现较好的乳化性,颗粒不会发生聚集,而当油水体积比为5:5时乳液的稳定性较好。     

氧化程度对羧酸型两性淀粉性能的影响

氧化型两性淀粉是一种新型的两性淀粉,同时包含羧基和阳离子基团。其制备采用两步法,先将淀粉阳离子化,再将阳离子淀粉氧化。阳离子淀粉最佳制备工艺为:淀粉乳浓度35%,醚化剂的用量为5%,pH11.6,反应先在50℃活化2h,再降温到45℃反应8h。通过添加不同量的NaClO到阳离子淀粉中制得羧基含量不同的两性淀粉,所得淀粉洁白,糊透明度高,稳定性强,凝沉性弱,热糊粘度也较阳离子淀粉明显下降,且这些性能均随羧基含量的增加而增强。      

变性淀粉糊稳定性的探讨

探讨了淀粉糊凝沉性机理，并从淀粉原料和淀粉交联变性角度讨论了影响淀粉糊稳定性的关键因素，为变性淀粉生产和应用提供理论指导。     

海藻酸钠对木薯淀粉衍生物糊性质的影响

采用Brabender黏度计和哈克流变仪研究了海藻酸钠对木薯阴离子和木薯阳离子淀粉糊性质的影响。Brabender结果表明:海藻酸钠提高了木薯阳离子淀粉的起始糊化温度,显著增加了峰值黏度、崩解值和回生值;加入海藻酸钠后,木薯阴离子淀粉呈现出不同的变化趋势,起始糊化温度降低,崩解值和回生值变化不大。在冻融稳定性方面,海藻酸钠降低了木薯阴离子淀粉的析水率,但却使木薯阳离子淀粉的析水率升高。流变学特性结果表明:所有淀粉及淀粉-海藻酸钠体系淀粉糊均为假塑性流体、弱凝胶,且加入海藻酸钠后,淀粉糊假塑性增强,淀粉凝胶的tanδ均增大,凝胶向趋于流体的方向发展。     

小麦淀粉糊化的影响因素及黏度稳定性研究

以小麦淀粉为材料,采用快速黏度分析仪(RVA)研究不同外力作用、温度和浓度下小麦淀粉糊的形成及其稳定性,为淀粉食品加工参数的确定及其品质控制提供依据.结果表明,浓度、温度和外力对小麦淀粉的糊化和稳定性均有影响.在一定条件下小麦淀粉的糊化经历了黏度的上升、下降和回升过程.较高浓度(16%～20%)的淀粉糊的稳定性较好,低浓度的淀粉糊(4%)在低温(50℃)下稳定性较差,有老化趋势;较低温度(80℃左右)糊化的小麦淀粉具有较好的稳定性;研究范围内较高的搅拌速度可以获得较高的黏度和较稳定的淀粉糊;反复搅拌导致淀粉糊的黏度下降,稳定性提高.     

交联淀粉性能与鲜粉丝耐煮性关系

本文以马铃薯淀粉、红薯淀粉和木薯淀粉为原料,三氯氧磷为交联剂,氯化钠为膨胀抑制剂,制备了不同交联度的交联淀粉,研究了交联对薯类淀粉性能及鲜粉丝耐煮性的影响。采用断条率、吸水率表征鲜粉丝的耐煮性,采用沉降积法测定淀粉的交联度。结果表明:交联淀粉用量和交联度对鲜粉丝耐煮性均有影响。淀粉经交联后,其蓝值、膨胀能力降低,但其冻融稳定性增加。     

阳离子聚合物对二次胶粘物稳定性及沉积性能的影响

以丙烯酸酯压敏胶作为废纸回用中二次胶粘物的模型物,研究了阳离子聚合物对二次胶粘物稳定性及其在浆水体系中沉积性能的影响.结果表明,高分子质量、低电荷密度的阳离子聚丙烯酰胺和阳离子淀粉主要通过桥联机理造成二次胶粘物的失稳,而低分子质量、高电荷密度的聚乙烯亚胺则通过电荷补丁机理导致其失稳.低用量的阳离子聚合物可以引起二次胶粘物沉积,大量的聚乙烯亚胺和阳离子聚丙烯酰胺通过将二次胶粘物粒子固着到纤维上减少沉积,而大量的阳离子淀粉除了将部分二次胶粘物粒子固着到纤维上减少沉积外,还能通过吸附到二次胶粘物粒子上降低其粘性而减少树脂沉积.     

Studies on Cross-linked A. paniculatas (Rajgeera) Starch

Earlier studies from our laboratories on waxy A. paniculatas starch have shown it to be sensitive to mechanical shear and acidity. Cross-linking of this starch with phosphorus oxychloride at room temperature for ten min using 5 ml POCI₃ per 100 g starch improved the stability under canning conditions, low pH and also mechanical shear. Its paste clarity also improved distinctly. However, it had very poor freeze-thaw stability indicating it to be unsuitable for frozen foods. Evaluation of this starch in canned tomato soup showed it to be a useful thickener for foods processed under retort conditions.     

Effects of cationization on DSC thermal profiles,pasting and emulsifying properties of sago starch

Cationic sago starches were prepared using an aqueous alkaline process with different levels of cationic reagent 3‐chloro‐2‐hydroxypropyltrimethylammonium chloride (0.01–0.10 M ), sodium hydroxide (0.03–0.86 M ) and reaction temperature (30–62 °C). The degree of substitution (DS), reaction efficiency, thermal and pasting properties of cationic sago starches were analysed. Emulsifying and fat binding properties of native sago starch, cationized sago starch and commercial chitosan were compared at two different pH values (4 and 7). Degree of substitution increased with an increase in concentration of cationic reagent or NaOH, or reaction temperature. The reaction efficiency was proportional to the concentration of NaOH and reaction temperature but inversely proportional to the cationic reagent concentration. The highest DS and reaction efficiency achieved was 0.06 and 79%, respectively. The pasting temperature and gelatinization enthalpy of cationic starch (DS 0.06) were lower compared with native sago starch. Cationization increased the peak viscosity and breakdown of the starch paste but decreased the setback. The presence of cationic groups significantly increased emulsion stability, emulsion viscosity and fat binding capacity of sago starch. However, the cationic sago starch was still inferior to chitosan, which showed the highest emulsion stability, emulsion viscosity and fat binding capacity. There was no significant difference between the surface tension values of native and cationic sago starch and chitosan. The influence of pH on emulsifying properties was not significant. The emulsion stability of the cationic sago starch improved due to an increase in viscosity and fat binding capacity but not its surface active property. Copyright © 2004 Society of Chemical Industry     

Stabilization of Soil Particles to Water: Effect of Cations

Tertiary cationic starch, quaternary cationic starch and cationic starch graft copolymers were each prepared at several levels of cation content. Together with some commercial cationic starches, these materials were assayed by wet sieving to determine their ability to convey water stability to soil. Cations neither increase nor decrease the capacity of starch to stabilize the soil used in this study. Guar, which has excellent stabilizing action (88% soil was retained after wet sieving at treatment level of less than 0.1 g per 100g of soil), behaved similarly: Cation functionality did not influence stabilization. Cationic starch derivatives used as soil stabilizers promised low cost and easy application. However, their low activity, less than onefourth that of synthetics, casts doubt on their use for this purpose.     

湿法制备高黏度玉米变性淀粉的工艺研究

应用湿法,以普通玉米淀粉为原料,在交联变性之后,进行阳离子醚化反应。以峰值黏度为评价指标,应用单因素实验法和正交实验法筛选和优化了工艺条件,并对其黏度特性进行了比较研究。制得的淀粉峰值黏度可达2 433 BU,约是原淀粉黏度的8倍,且糊液的黏度稳定性也有很大的提升。优化的制备工艺参数为:阳离子醚化剂用量为淀粉干基质量的10%,反应温度41℃,反应时间12 h,反应pH值11.3,NaOH与醚化剂摩尔比为1.2∶1。