食用羟丙基淀粉的研究

用化学方法对淀粉分子结构进行改造,使其部分脱水葡萄糖单位上的羟基与烷基化试剂反应生成羟丙基淀粉。经羟丙基醚化后的淀粉糊化温度明显降低,糊化速度大大加快,老化现象改善,凝胶较为透明清晰,在冷藏、冻融以及微酸性条件下,能保持凝胶的稳定性。参照F.C.C标准,羟丙基淀粉可供食用。动物毒理试验结果无异常。性能稳定。食用羟丙基淀粉可以代替或部分代替天然胶(果胶、阿拉伯胶等)。     

交联和羟丙基改性对蜡质玉米淀粉糊性能的影响

本研究采用蜡质玉米淀粉为原料,湿法工艺制备了磷酸酯双淀粉(1412)、羟丙基淀粉(1440)和羟丙基二淀粉磷酸酯(1442),通过对蜡质玉米淀粉(WS)和3种变性淀粉(1412、1440、1442)在黏度、抗剪切、耐酸性、冻融稳定性和透明度等性能的比较,探讨了羟丙基醚化和交联改性处理对蜡质玉米淀粉糊性能的影响。试验结果显示:⑴羟丙基改性处理降低了淀粉的糊化温度,提高了淀粉峰值黏度,透明度和冻融稳定性得到显著改善,但热稳定性、耐酸性和抗剪切均较差;⑵磷酸盐交联改性的磷酸酯双淀粉糊化温度升高,峰值黏度降低,糊液在抗剪切、耐酸性方面得到显著改善,但糊液透明度降低,冻融稳定性未得到改善;⑶通过交联和羟丙基改性的羟丙基二淀粉磷酸酯,兼具有磷酸酯双淀粉和羟丙基淀粉的共同特性。     

影响马铃薯羟丙基二淀粉磷酸酯黏度特性的因素研究

通过测定变性淀粉的Brabender黏度特性,研究了马铃薯淀粉(PS)品质(依黏度指标分为优级粉、一级粉和合格粉三级)、磷酸酯化程度、羟丙基醚化程度、产品电导率对马铃薯羟丙基二淀粉磷酸酯(HPSP)黏度特性的影响。实验结果显示:(1)马铃薯淀粉的品质对糊化温度和峰值黏度有较大影响,以优级品为原料制备的羟丙基二淀粉磷酸酯的糊化温度最低,峰值黏度最高;(2)轻度磷酸酯化的羟丙基二淀粉磷酸酯具有较高的峰值黏度和冷黏度,随着磷酸酯化程度的提高,马铃薯羟丙基二淀粉磷酸酯的糊化温度增高,峰值黏度降低;(3)羟丙基醚化对马铃薯羟丙基二淀粉磷酸酯的黏度值影响较小,随羟丙基含量的升高,糊化温度明显降低,峰值黏度和冷黏度则略有上升;(4)随着马铃薯羟丙基二淀粉磷酸酯电导率的降低,产品的糊化温度降低,峰值黏度和冷黏度升高。     

普通玉米杂交种间原淀粉与羟丙基淀粉糊化性质关系的研究

本文采用湿法在实验室的条件下提取了17种普通玉米杂交种淀粉，并制取了羟丙基淀粉。采用快速粘度测定仪（RVA）测定了所有淀粉的糊化性质参数。结果表明：羟丙基淀粉提高了所有原淀粉的峰值和破损值；降低了所有原淀粉的谷值、终粘度、回生值、出峰时间和成糊温度；原淀粉和羟丙基淀粉的糊化性质参数在普通玉米杂交种间均达到了极显著相关水平，表明了羟丙基淀粉并没有改变原淀粉在普通玉米杂交种间的糊化性质差异性。羟丙基淀粉的糊化性质参数间的相关性显著水平发生了明显的变化，表明了不同的普通玉米杂交种的羟丙基淀粉的糊化性质参数的变化幅度是不同的。但是，羟丙基和原淀粉的相同糊化性质参数间的相关性都达到极显著的正相关水平，说明了羟丙基淀粉与原淀粉的糊化性质参数间存在密切关系，二者的糊化性质又存在着一致性。     

羟丙基交联木薯淀粉对籼米淀粉老化特性的影响

以籼米淀粉为原料,考察添加不同比例的羟丙基交联木薯淀粉(HP-CLTS),对籼米淀粉粘度特性以及样品糊化后贮藏过程中持水力、质构特性、外貌形态和红外光谱的影响,发现随HP-CLTS添加量增加,籼米淀粉糊化温度、衰减值逐渐降低,而峰值粘度、热糊粘度、崩解值、终值粘度呈升高趋势。样品贮存过程中持水力增强而凝胶硬度显著下降(p<0.05);添加HP-CLTS后混合淀粉糊化凝胶4℃老化7d的冻干样品,扫描电镜观察显示添加HP-CLTS的淀粉凝胶具有比纯籼米淀粉更疏松多孔的网络空腔结构,从微观结构上证明了HP-CLTS具有高的持水能力,能老化过程中凝胶水分损失;凝胶傅里叶红外光谱显示随HP-CLTS添加量增加1047cm-1处吸收峰减弱,而1022cm-1处的峰强度增强,说明HP-CLTS能够抑制籼米淀粉老化结晶。结果表明添加一定量HP-CLTS能有效抑制籼米淀粉老化。     

马铃薯淀粉及其7种变性淀粉糊液特性的比较研究

通过对马铃薯淀粉(PS)及其7种变性淀粉(醋酸酯淀粉、羟丙基淀粉、磷酸酯双淀粉、乙酰化二淀粉磷酸酯、羟丙基二淀粉磷酸酯、氧化淀粉、氧化羟丙基淀粉)在糊化温度、峰值黏度、热稳定性、凝胶性、抗剪切、耐酸性、冻融稳定性和透明度等性能差异的研究,探讨了不同改性方式对马铃薯淀粉糊特性的影响。结果表明:⑴羟丙基和醋酸酯改性均可降低马铃薯淀粉的糊化温度,提高淀粉峰值黏度,增加糊液透明度和冻融稳定性,但淀粉糊的热稳定性和凝胶性差;⑵交联改性提高了马铃薯淀粉的糊化温度和凝胶性,增强了糊液热稳定性和耐酸性,但透明度降低;⑶氧化处理降低了马铃薯淀粉的糊化温度和峰值黏度,提高淀粉糊透明度;(4)双重改性处理的复合变性淀粉同时兼有二种单一变性淀粉的共同特性,其中:氧化羟丙基淀粉的透明度最好,羟丙基二淀粉磷酸酯的冻融稳定性最好。     

羟丙基甘油双淀粉的研究及应用

本文较详细地介绍了以玉米淀粉为主要原料生产羟丙基甘油双淀粉的最佳条件。羟丙基甘油双淀粉湖液的透明度、冻融稳定性、粘液稳定性及其在不同pH值条件下糊液粘度变化曲线。本文还介绍了该产品在食品、造纸等行业中实际应用的情况。     

羟丙基淀粉颗粒形貌和结晶结构的研究

本文应用扫描电镜、X-光衍射和偏光显微等现代分析技术，观察和研究了不同取代度羟丙基淀粉和原淀粉的颗粒形貌及其结晶结构。结果表明：淀粉羟丙基化反应首先发生在淀粉颗粒中结构较薄弱的非结晶区。随着取代度增大，淀粉颗粒表面发生凹凸不平变化，出现洞穴和裂痕，使淀粉易于糊化，糊化温度降低。     

木薯羟丙基淀粉制备工艺的研究

以木薯淀粉为原料,环氧丙烷为醚化剂,硫酸钠为淀粉膨胀抑制剂,采用湿法工艺制备木薯羟丙基淀粉,以产品摩尔取代度(MS)为评价指标,通过单因素试验分别探讨了环氧丙烷用量、硫酸钠用量、反应pH值、反应温度、反应时间等对羟丙基醚化反应的影响,在此基础上应用正交试验确定了木薯羟丙基淀粉制备的最佳工艺条件。试验结果显示:(1)随环氧丙烷用量的增大,取代度逐渐升高,反应效率逐渐降低;(2)适当提高反应pH和反应温度有利于取代度的提高,但反应pH值超过11.5和反应温度超过45℃,会导致淀粉的局部糊化,不利于醚化反应的进程。制备木薯羟丙基淀粉的最佳工艺条件为:淀粉乳浓度40%,环氧丙烷添加量10%(对干基),硫酸钠添加量12%(对干基),反应pH值11.5,反应温度40℃,反应时间22 h。所得木薯羟丙基淀粉的取代度为0.143。     

不同原料羟丙基二淀粉磷酸酯性能比较及在酸乳中应用

研究了以马铃薯淀粉、木薯淀粉、蜡质玉米淀粉和玉米淀粉为原料制备的羟丙基二淀粉磷酸酯在Brabender黏度曲线、不同介质中黏度、透明度和冻融稳定性等性能差异,探讨了不同原料羟丙基二淀粉磷酸酯在酸乳的制作中对酸乳黏度、贮藏稳定性及感官评价的影响。实验结果显示:(1)马铃薯羟丙基二淀粉磷酸酯具有较低的糊化温度和较高的峰值黏度;(2)蔗糖和柠檬酸能不同程度地提高羟丙基二淀粉磷酸酯的黏度;(3)较之玉米羟丙基二淀粉磷酸酯,马铃薯、木薯和蜡质玉米羟丙基二淀粉磷酸酯具有更好的冻融稳定性;(4)4种羟丙基二淀粉磷酸酯透明度均不高;(5)4种变性淀粉均可不同程度改善酸乳的品质,提高酸乳的稠度,降低乳清析出率和提高产品贮藏期。     

壳聚糖木薯淀粉明胶复合可食抗菌保鲜膜性能的研究

研究了壳聚糖/木薯淀粉/明胶/甘油共混膜的机械性能、透湿性能、透气性能及共混涂膜的防腐保鲜效果。结果表明,木薯淀粉、明胶、甘油、木薯淀粉与明胶交互作用对共混膜的抗拉强度影响显著;对断裂伸长率影响显著的因素为木薯淀粉、明胶、甘油及其二次项、明胶与甘油的交互项;对共混膜透湿系数影响显著的主要因素是木薯淀粉、甘油、木薯淀粉与木薯淀粉之间的交互作用;木薯淀粉、明胶、木薯淀粉与木薯淀粉之间的交互作用对共混膜的透气系数影响也是显著的。此外,此共混涂膜具有一定的防腐作用。     

高直链玉米淀粉/羟丙基甲基纤维素可食性膜的制备及性能研究

以高直链玉米淀粉(HACS)和羟丙基甲基纤维素(HPMC)为主要成膜基材,采用溶液流延法制备了HACS/HPMC可食性膜。研究了不同配比的HACS与HPMC对可食性膜的结晶性能、力学性能、亲水性能和水蒸气阻隔性能等的影响。结果表明,随着HPMC比例的增大,HACS与HPMC之间的氢键作用减弱,复合膜的水溶性增大,连续相由HACS转变为HPMC,但HACS与HPMC的相容性变差。HPMC可有效降低可食性膜的结晶程度并抑制其在储藏过程中的老化。在复合膜中,当HACS与HPMC比例为8∶2时,可食性膜具有最大抗拉强度(7.5 MPa)、断裂伸长率(14.7%)、水接触角(84.33°)和最低水蒸气透过系数(2.17×10~(-10 )g·m·m~(-2)·s~(-1)·Pa~(-1))。纯HACS膜和纯HPMC膜的透光性能均优于HACS/HPMC复合膜。     

冻融处理对淀粉膜结构、热稳定性、机械性能及物理性质的影响

本实验分别以天然马铃薯淀粉（potato starch,PS）、改性马铃薯淀粉（包括羟丙基二淀粉磷酸酯（hydroxypropyl distarch phosphate,HDP）、醋酸淀粉（acetate starch,AS）和氧化淀粉（oxidized starch,OS））为基材,通过流延法制备可食用淀粉膜,考察冻融处理对膜物理性质、机械性能、阻隔性能、微观结构和热稳定性的影响。X射线衍射结果表明,马铃薯来源的淀粉颗粒具有典型的B型晶体结构,在成膜过程中淀粉结晶度降低,冻融处理后淀粉膜晶体峰强度明显减弱。扫描电子显微镜观察结果显示,冻融处理破坏了淀粉膜的微观结构,其中PS膜上出现明显裂纹,AS膜上出现蜂窝和层状结构,而HDP和OS淀粉膜具有更完整的形态。热重分析结果表明,随着温度的升高,淀粉膜的热重曲线出现4 个质量损失阶段,分别对应水分散失、甘油挥发、淀粉解聚及淀粉分解,而冻融处理对膜热稳定性影响较小。常温条件下,PS膜具有最佳的机械性能,其拉伸强度为2.29 MPa,断裂伸长率为68.82%。在3 个冻融循环后,淀粉膜的拉伸强度至少增加了2 倍,断裂伸长率普遍降低,而溶解度和水蒸气透过率仅有轻微变化。综合考虑不同淀粉膜微观结构、机械性能、水蒸气透过率及水溶性,HDP膜表现出更好的冻融稳定性,可应用于冷冻低水分食品的保藏。     

几种涂布淀粉的制备及其性能研究

以制备成本基本相当为前提,采用木薯淀粉浆为原料,制备磷酸酯涂布淀粉、醋酸酯涂布淀粉和羟丙基涂布淀粉。通过对3种涂布淀粉的性能研究对比,结果表明：3种涂布淀粉均具有优良的黏结强度、成膜性、流变性和保水性,能满足高浓度淀粉蒸煮糊化、高固含量涂料配制及高速涂布的需要;其中,木薯醋酸酯涂布淀粉的总体应用性能最优,木薯羟丙基涂布淀粉次之。     

Oxidized banana starch–polyvinyl alcohol film: Partial characterization

Composites of polyvinyl alcohol, native banana starch, oxidized banana starch using glycerol like plasticizer, were studied by mechanical tests (MT), scanning electronic microscopy (SEM), differential scanning calorimetry (DSC) and solubility in water. The oxidized banana starch showed higher level of carboxyl groups than of carbonyl groups. Composites of native banana starch/polyvinyl alcohol and oxidized banana starch/polyvinyl alcohol showed irregularities, indicating incomplete dispersion of the polymers. However, the film elaborated with the blend oxidized banana starch/polyvinyl alcohol showed the highest mechanical properties and the melting temperature of the first transition, as well as the lowest water vapor permeability, indicating higher interaction between both polymers. The composite oxidized banana starch/polyvinyl alcohol showed higher water solubility than the one of its counterpart with native banana starch at 25°C, and similar values were obtained for both films at 60°C. The oxidation of banana starch in order to elaborate a film blended with polyvinyl alcohol improved some mechanical and barrier properties, and this composite could be used for specific applications in the packing of food.     

Development of oxidised and heat-moisture treated potato starch film

This study investigated the effects of sodium hypochlorite oxidation and a heat-moisture treatment of potato starch on the physicochemical, pasting and textural properties of potato starches in addition to the water vapour permeability (WVP) and mechanical properties of potato starch films produced from these starches. The carbonyl contents, carboxyl contents, swelling power, solubility, pasting properties and gel texture of the native, oxidised and heat-moisture treated (HMT) starches were evaluated. The films made of native, oxidised and HMT starches were characterised by thickness, water solubility, colour, opacity, mechanical properties and WVP. The oxidised and HMT starches had lower viscosity and swelling power compared to the native starch. The films produced from oxidised potato starch had decreased solubility, elongation and WVP values in addition to increased tensile strength compared to the native starch films. The HMT starch increased the tensile strength and WVP of the starch films compared to the native starch.     

Production and characterization of oxidized cassava starch (Manihot esculenta Crantz) biodegradable films

Plastic is one of the most common pollutants in the environment. Therefore, the number of studies on the use of biodegradable packaging is increasing. Starch is the primary material used in the production of biodegradable plastics due to its natural abundance and high biodegradability. Yet, the strong hydrophilic character of starch presents a challenge. Therefore, the modification of its structure through oxidation may yield interesting results as the viscosity reduction. The objectives of this work were to obtain cassava (Manihot esculenta Crantz) starch oxidized with 0.8 and 2.0% active chlorine, to develop biodegradable films and characterize their mechanical properties, solubility in water, permeability to water vapor, degree of swelling, and sorption isotherms. Biodegradable films were produced with starch concentrations of 2, 3, 4, and 5% w/w and 25% glycerol (g/100 g starch) added as a plasticizer. Images of the films were obtained with an atomic force microscope and allow to observe a smooth surface and the absence of starch granules in the film produced with oxidized starches. The tensile strength of the biodegradable film produced with oxidized starch (0.8% active chlorine) was 80 MPa. The value of permeability to water vapor was 1.613 × 10⁻⁹ kg/day/m/Pa, and the average solubility was 41%. The sorption isotherms showed that biodegradable films made with oxidized starches cannot be used in environments with relative humidity below 35% or above 90%.     

Preparation and properties of rice starch–chitosan blend biodegradable film

Biodegradable blend films from rice starch–chitosan were developed by casting film-solution on leveled trays. The influence of the ratio of starch and chitosan (2:1, 1.5:1, 1:1, and 0.5:1) on the mechanical properties, water barrier properties, and miscibility of biodegradable blend films was investigated. The biodegradable blend film from rice starch–chitosan showed an increase in tensile strength (TS), water vapor permeability (WVP), lighter color and yellowness and a decreasing elongation at the break (E), and film solubility (FS) after incorporation of chitosan. The introduction of chitosan increased the crystalline peak structure of starch film; however, too high chitosan concentration yielded phase separation between starch and chitosan. The amino group band of the chitosan molecule in the FTIR spectrum shifted from 1541.15 cm⁻¹ in the chitosan film to 1621.96 cm⁻¹ in the biodegradable blend films. These results pointed out that there was a molecular miscibility between these two components. The properties of rice starch–chitosan biodegradable blend film and selected biopolymer and synthetic polymer films were compared; the results demonstrated that rice starch–chitosan biodegradable blend film had mechanical properties similar to the other chitosan films. However, the water vapor permeability of rice starch–chitosan biodegradable blend film was characterized by relatively lower water vapor permeability than chitosan films but higher than polyolefin.     

淀粉成膜性和疏水性对表面施胶包装纸的影响

本文研究了添加甘油对疏水改性木薯淀粉膜力学性能及阻隔性能的影响,甘油的添加降低了疏水改性淀粉膜的玻璃转化温度、储能模量及水蒸气透过量.当温度低于临界温度上限时,疏水改性淀粉将会出现固态及液态两种形式.热的淀粉溶液中加入适量的甘油可以抑制淀粉微粒的沉淀.与羟丙基淀粉相比,疏水改性淀粉中添加不同量的甘油并涂覆干基材表面,对基材的阻隔性、水蒸气透过量、接触角及可勃吸水值均有一定影响.从表面施胶基材的可勃吸水值和水蒸气透过量的变化上可以看出,淀粉的成膜性对基材的性能有非常重要的影响.良好的成膜性可以改善基材的阻气、阻湿性,而对基材表面润湿性的影响不大.随着甘油含量的逐渐增加,基材的水蒸气透过量不断减少;但仍无法得到较好的阻湿性能.本文中所用的疏水改性淀粉具有较好的氧气阻隔性能和接触角,因此,表面施胶后的基材具有较好的疏水特性.同时在实验条件下研究了淀粉沉淀对基材性能的影响,利用淀粉沉淀对基材表面进行施胶后即使淀粉成膜性较差,也可以得到较低的水蒸气透过量和较高的接触角.通过增加疏水改性淀粉中甘油的含量,表面施胶基材的可勃吸水值可以得到显著改善.     

硼酸交联对挤出吹塑变性淀粉/聚乙烯醇复合膜性能的影响

为了提高淀粉基复合膜的阻水性,拓宽淀粉膜的应用范围,以羟丙基二淀粉磷酸酯与聚乙烯醇(PVA)为成膜原料,硼酸为交联剂,采用挤出吹塑工艺制备了淀粉/PVA复合膜。分析了粒料的流变性能,研究了淀粉膜的交联密度、力学性能、阻隔性能、疏水性能以及微观形貌等性质。结果表明,随着硼酸添加量的增加,淀粉/PVA复合材料的熔体流动性下降,淀粉/PVA复合膜的阻氧、阻水性能增强,而淀粉膜的抗拉强度和拉伸模量呈降低趋势,断裂伸长率先升高后降低。添加1%的硼酸,淀粉/PVA复合膜的表面更加均匀平整,疏水性最强,具有最小的溶胀度、最大的凝胶质量和最高的交联密度。