木薯淀粉水凝胶的制备及表征

采用木薯淀粉接枝丙烯酰胺,以淀粉为骨架,接枝上丙烯酰胺支链,以期形成具有敏感性的空间网状大分子结构水凝胶。以木薯淀粉为原料,丙烯酰胺为单体,以N,N-亚甲基双丙烯酰胺为交联剂,过硫酸铵为引发剂,制备具有高溶胀性能的木薯淀粉基水凝胶,研究了水凝胶对温度pH的敏感特性。通过傅里叶红外光谱(FTIR)、场发射扫描电子显微镜(FE-SEM)、X-射线衍射仪(XRD)等现代分析测试手段对其进行表征。实验结果表明:当木薯淀粉用量为1 g,丙烯酰胺用量为5 g,N,N-亚甲基双丙烯酰胺为0.06 g,过硫酸铵0.03 g时,制得的木薯淀粉水凝胶吸水倍率较高。表征结果证明已成功制备木薯淀粉水凝胶。水凝胶溶胀平衡比会随着温度以及pH的改变而改变,溶胀比在35 ℃时达到最大,在pH为12.24碱性条件下溶胀性达到最高,表明制备的水凝胶具有温度与pH双敏感性。该水凝胶良好的溶胀性能可以使其用于重金属离子吸附、生物医药等领域,应用价值较高。     

羟丙基木薯淀粉水凝胶的构建及性能研究

近年来,淀粉基水凝胶的研究备受关注,但是天然淀粉水凝胶存在高脆性、低拉伸性等缺陷,限制了它的应用。本研究旨在通过羟丙基改性木薯淀粉提高其凝胶特性,并将羟丙基木薯淀粉与玉米淀粉复配,探究复配淀粉水凝胶的性能。结果表明,木薯淀粉经羟丙基化改性后,焓值从14.885 J/g降低到7.780 J/g,结晶度由28.2%降低到22.1%,其构成的水凝胶拉伸应变从320%提高到550%。通过将羟丙基木薯淀粉与玉米淀粉复配,提高了复配淀粉凝胶的拉伸应变,能够拓展其在工业、农业、食品等领域的应用。     

木薯淀粉水凝胶的微波合成表征及性能测试

以木薯淀粉为原料,丙烯酰胺为单体,N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂,采用微波辐射技术辅助制备木薯淀粉基水凝胶。探究单体、交联剂、引发剂用量等因素对水凝胶溶胀性能的影响。当淀粉与丙烯酰胺用量比为1∶3,N,N-亚甲基双丙烯酰胺为0.02 g,过硫酸钾0.05 g时,微波400 W,60 s制得的木薯淀粉水凝胶达最高吸水倍率。通过傅里叶红外光谱仪(fourier transform infrared spectrometer,FTIR)、场发射扫描电子显微镜(field emission scanning electronic microscope,FESEM)等分析测试手段对其进行表征,结果表明已成功制备木薯淀粉基水凝胶。该水凝胶溶胀平衡比在35℃时达到最大,且在室温条件下保水性良好。该研究为淀粉水凝胶的制备应用提供了实验依据,提高了木薯淀粉的附加值。     

几种木薯变性淀粉凝胶化性质的研究

对木薯醋酸酯淀粉、磷酸酯淀粉和氧化淀粉的糊化性质、流变特性和凝胶强度等凝胶化性质进行了比较研究.研究表明:醋酸酯淀粉和磷酸酯淀粉的糊化温度与原淀粉相当,氧化淀粉的糊化温度降低.醋酸酯淀粉和磷酸酯淀粉糊具有剪切稀化特性,属假塑性流体,氧化淀粉糊呈牛顿流体的特征.3种变性淀粉糊的表观粘度受浓度、温度和pH值的影响,与木薯原淀粉相比,变性淀粉糊具有较好的耐热和耐酸碱稳定性.而凝胶强度因变性基团的不同,差异较大.     

木薯淀粉及木薯变性淀粉性质比较研究

测定了木薯淀粉、木薯羟丙基淀粉、羟丙基交联淀粉、醋酸酯淀粉、醋酸酯交联淀粉的冻融稳定性、透光率、凝沉、耐盐性、耐酸性、糊化特性等性质。实验结果表明:经过变性的木薯淀粉和原木薯淀粉有很大的不同,经过羟丙基化、羟丙基交联、醋酸酯化、醋酸酯交联后,分别引入了羟丙基、交联键、乙酰基等,使其具有较强的冻融稳定性,具有较高的透明度、耐盐性、耐酸性。据RVA分析,各种变性淀粉糊液性质较原淀粉有较大的提高。经过交联后糊液稳定性较原淀粉、羟丙基及醋酸酯淀粉有较大程度的提高,因此具有更为广阔的应用性。      

木薯改性淀粉对鹅血凝胶特性的影响

为研究木薯改性淀粉对鹅血凝胶特性的影响,将不同浓度的木薯改性淀粉与鹅血混合,测定鹅血凝胶的保水性、质构、色泽、流变特性、热特性和感官评价等指标。结果表明,木薯改性淀粉添加浓度为0.2%时,保水性与未添加木薯改性淀粉的鹅血相比提高11.14%;咀嚼性是未添加木薯改性淀粉的鹅血的2.07倍;鹅血凝胶的感官评分与未添加木薯改性淀粉的鹅血相比提高45.83%;弹性值是未添加木薯改性淀粉的鹅血的2.71倍。静态流变学分析表明,添加0.2%的木薯改性淀粉,凝胶的表观黏度和触变环面积较小,说明凝胶的塑性和流变稳定性得到改善。通过热力学分析,木薯改性淀粉添加浓度为0.2%时,鹅血凝胶的变性温度与未添加木薯改性淀粉的鹅血相比增加9.2 ℃,热焓是未添加木薯改性淀粉的鹅血的1.03倍,使得鹅血凝胶更稳定。可见0.2%的木薯改性淀粉与鹅血混合能够较好提高鹅血的凝胶特性。     

糯米淀粉水凝胶的制备及性质

研究淀粉水凝胶的制备条件和性质。用糯米淀粉为原料,以4-二甲基氨基吡啶为催化剂,经过琥珀酸酐酯化处理后产生糯米淀粉水凝胶。确定制备糯米淀粉水凝胶的最佳工艺条件为:琥珀酸酐与原淀粉羟基摩尔比为10∶1;催化剂与原淀粉羟基摩尔比为1.05∶1。通过红外结构分析及DSC差热分析确认在淀粉分子中成功引入了丁二酸基团。所获得的淀粉水凝胶具有良好的吸水能力,相比原淀粉,其透光率及冻融稳定性有较大程度提高。     

木薯淀粉微球的制备

以木薯淀粉为材料,N,N′-亚甲基双丙烯酰胺(MBAA)为交联剂采用反向乳化法制备木薯淀粉微球。研究了交联剂、引发剂等因素对载药量的影响,得到了最佳的制备工艺条件。采用扫描电镜(SEM)、红外光谱(IR)、XRD等对所制备的木薯淀粉微球进行了表征。结果表明制备的木薯淀粉微球呈表面粗糙的圆球形,大小为10μm,载药量增加明显并且有很好的缓释作用。     

红薯淀粉水凝胶制备及吸水特性研究

以红薯淀粉为原料,以4-二甲基氨基吡啶为催化剂,于水相中经过醋酸酐酯化处理制备红薯淀粉水凝胶。确定了制备红薯淀粉水凝胶的最佳工艺条件,红外光谱确认在淀粉中引入了羧甲基。红薯淀粉水凝胶吸水性增强,黏度增大,糊透明度得到改善,说明红薯淀粉水凝胶具有优良吸水特性。     

修饰预糊化木薯淀粉性能研究

介绍了经化学修饰后再进行预糊化制备得到的修饰预糊化木薯淀粉的性能，并与国产预糊化木薯淀粉和泰国泰花牌预糊化木薯淀粉的性能进行了比较。结果表明：修饰预糊化木薯淀粉的性能达到且超过泰国泰花牌预糊化木薯淀粉的性能，远远优于国产预糊化木薯淀粉。     

壳聚糖基纳米纤维载药体系及其缓释行为

为研制具有缓释效果的抗菌材料,以壳聚糖(CS)、聚乙烯醇(PVA)为原料,采用静电纺丝技术制备CS/PVA 复合纳米纤维膜并负载环丙沙星;探究纺丝体系、纺丝工艺对纤维膜微观形貌、接触角、化学结构的影响,分析药物体外释放行为及载药前后试样的抗菌性。结果表明：PVA 的加入提高了CS 的可纺性;改善了纤维膜的亲水性;当纺丝电压为24 kV、CS 和PVA 质量比为1：1. 5 时,纤维膜成网均匀,形貌良好;载药纳米纤维膜具有相对较低的药物释放速率,可有效避免药物突释,且药物释放速率随纤维膜中环丙沙星质量分数的增大而增大;载药CS/PVA 纳米纤维膜对金黄色葡萄球菌具有优良的抗菌性。     

木薯淀粉与木薯变性淀粉鱼糜加工性质的比较

摘要：本研究比较了木薯淀粉、木薯醋酸酯交联淀粉和木薯磷酸酯交联淀粉对鱼糜加工性质的影响,并测定了二种木薯醋酸酯交联淀粉、二种木薯磷酸酯交联淀粉以及木薯淀粉和鱼糜加工相关的冻融稳定性、透光率、溶解性、膨润度和凝沉性等特性。并将木薯淀粉和四种变性淀粉分别添加到鱼糜中,测定鱼糜冻融过程中的持水性、白度以及凝胶强度等品质特性。结果表明：木薯变性淀粉因引入了磷酸基、羧甲基等亲水性基团,在透光率、冻融稳定性、溶解性和凝沉性等性质方面较木薯淀粉均有提高,添加木薯变性淀粉所得到的鱼糜制品白度、持水性和凝胶强度分别增加了17.7%、10.2%、77.7%。木薯变性淀粉较木薯淀粉更适合用于加工鱼糜。     

Rheology of tapioca starch

Rheological properties of tapioca starch solutions were evaluated using a computer controlled rotational viscometer in relation to four factors: temperature, 20–80°C; concentration, 2–6%; pH, 4–8 and cooking time, 5–35 min. All test solutions showed power-law flow behavior. A second order composite design was used to investigate the effects of concentration, temperature, pH value and cook time on rheological property parameters (consistency coefficient, m, and flow behavior index, n), and develop second order multiple response models of parameters related to concentration, temperature, pH value and cook time.     

Thermal properties of tapioca starch

Thermal properties of native tapioca starch, including thermal conductivity, specific heat, and thermal diffusivity at 4, 15, and 30% moisture contents, and 25, 50, and 75°C temperature levels were studied. Thermal conductivity was measured using a line‐heat source thermal probe equipped with a computerized data acquisition system; specific heat was measured using Differential Scanning Calorimetry (DSC) and thermal diffusivity was calculated from the thermal conductivity, density, and specific heat. Thermal conductivity, specific heat, and thermal diffusivity increased with the increase of temperature and/or moisture content. Prediction models for the thermal properties of tapioca starch were developed for practical applications.     

能量缓释淀粉微球的初步制备研究

采用乳化离子交联法初步制备能量缓释淀粉微球,探索各制备参数对工艺的影响,以获得更高的慢消化淀粉含量。以微球形态、包埋率、SDS提高率三个指标来评价制备工艺的效果。结果表明:随着海藻酸钠的浓度的增加,微球包埋率增大而SDS提高率呈现出先增后减的趋势;随着碳酸钙含量的增加,微球的包埋率和SDS提高率都是先增后减;乳化剂的加入有利于微球颗粒的良好成型,但是随着添加量的增加,微球的包埋率和SDS提高率都是先增大后减小。海藻酸钠的浓度范围为1.4%～1.6%,碳酸钙含量范围为2.0%～2.5%,加入1.0‰司盘-80作为乳化剂,能得到形态完整,球形度良好的,粒径在100～140μm,包埋率在80%以上的淀粉微球,其SDS提高率达到7%以上。      

Characteristics of microencapsulated β-carotene formed by spray drying with modified tapioca starch,native tapioca starch and maltodextrin

Acid-modified tapioca starch, native tapioca starch, and maltodextrin were tested for their ability to serve as wall materials for encapsulating β-carotene. The modified tapioca starch had wider particle size distribution, toward the smaller diameters, as compared to its native starch and maltodextrin. Moisture content and water activity of microcapsules were found to be dependent on type of wall materials. There were differences in total β-carotene and surface β-carotene contents among samples. The total β-carotene was highest for modified tapioca starch while it was lowest for maltodextrin. The surface β-carotene was lowest for modified tapioca starch while it was highest for native tapioca starch. The modified tapioca starch was more effective than its native starch in β-carotene retention. Results obtained suggest that the modified tapioca starch can be considered as potential wall material for encapsulation of β-carotene.     

木薯醋酸酯淀粉的制备及性能研究

以木薯淀粉为原料,醋酸酐为酯化剂,研究获得制备木薯醋酸淀粉的最佳工艺条件为:醋酸酐量为7％(对干基),pH8.5,反应时间60min,反应温度25℃.所制得的淀粉乙酰基含量为2.09％,反应效率为77.2％.对不同取代度(DS)醋酸酯淀粉的黏度、透明度、冻融稳定性等特性进行了研究.     

超声辅助制备淀粉微晶及其对姜黄素的吸附

本研究以玉米淀粉为研究对象,采用超声波辅助酸醇法制备淀粉微晶。以制备过程中的水解温度、盐酸浓度、乙醇浓度、水解时间为单因素变量,通过单因素实验设计和响应面实验设计,探究不同实验处理的淀粉微晶对姜黄素的吸附性,优化淀粉微晶的制备方法。最佳工艺条件为:盐酸浓度2.2 mol/L、乙醇体积分数59%、水解温度51℃、水解时间69.5 h,此条件下淀粉微晶对姜黄素吸附量为2.422 mg/g,比原淀粉的吸附量提高241.61%,且得到的淀粉微晶晶型不改变,吸附位点和比表面积增加。此方法反应条件简易可控,适合工业化生产,制备得到的淀粉微晶吸附性能良好,增加了淀粉的应用价值及应用方向。     

High pressure-induced tapioca starch gels: physico-chemical characterization and stability

Gelatinization of tapioca starch (25% dry basis) was induced by high hydrostatic pressure processing (HPP) at 600 MPa under different time and temperature regimes (30 °C for 10, 20 and 30 min; 50 °C for 10 min; 80 °C for 10 min). Textural, thermal and structural properties of the gels were studied and their stability was evaluated after 28 days of refrigerated (4 °C) and frozen (−18 °C) storage. Thermally induced gels (90 ± 1 °C, 20 min, gel-T) were used as controls. HPP resulted in the formation of harder gels than thermal processing (more significantly at lower processing temperatures) partially preserving the granular structure of the native starch. Longer HPP treatments caused only a slight decrease in hardness that was significant only at longer processing times (30 min). DSC thermograms of high pressure-induced samples showed a more asymmetrical ice-melting peak than that of thermally induced gels. Asymmetry of the peak of HP treated samples was more pronounced in samples processed at lower than at higher temperature. A different starch–water and/or starch/starch interaction may be hypothesized. During storage, all samples became stiffer and the amylopectin recrystallization increased, more extensively in thermally induced than in HPP samples where a stronger starch–starch and/or starch/water interactions may have hindered the recrystallization process.