凉薯淀粉的理化性质研究

以玉米淀粉、木薯淀粉和马铃薯淀粉为对照,分析了凉薯淀粉的颗粒形貌及大小、溶解度、膨胀度和糊化特性等理化性质。结果表明:凉薯淀粉颗粒形状多为不规则多边形,少数为圆形,粒径范围为3~11μm,平均粒径为8μm,小于其他三种淀粉;溶解度和膨胀度比木薯淀粉和玉米淀粉高,比马铃薯淀粉低,且随温度升高,溶解度和膨胀度显著增大;糊化温度为80℃,高于其他三种淀粉,峰值黏度小于木薯、马铃薯淀粉,高于玉米淀粉,糊化热稳定性比其他三种淀粉强,回生能力比玉米、马铃薯淀粉强,比木薯淀粉弱;透明度较低,易凝沉,表观黏度较小,表现出剪切稀释现象,冻融稳定性较差;凝胶硬度、咀嚼性、黏聚性、黏附性远低于马铃薯、木薯淀粉,高于玉米淀粉,且凝胶弹性最低。     

交联-羧甲基木薯淀粉的合成及性质研究

以木薯淀粉为原料,用环氧氯丙烷作交联剂,氯乙酸作羧甲基化试剂,合成交联-羧甲基复合变性淀粉并确定交联-羧甲基复合变性淀粉合成工艺的最佳条件。与原木薯淀粉相比,交联-羧甲基反应后产物黏度增大,膨胀凝固性、热稳定性、透明度得到改善。红外光谱分析发现,在1 008~1 164cm-1的吸收峰强度加强,证实在淀粉中引入了羧甲基。差示扫描量热分析表明,交联-羧甲基淀粉有较高的糊化温度,且更易糊化。     

不同类型变性淀粉的理化特性比较

以8种类型变性淀粉为研究对象,对其冻融稳定性、糊化特性、透明度、凝沉性、凝胶强度等理化特性进行研究。结果表明,预糊化羟丙基二淀粉磷酸酯蜡质玉米淀粉的冻融稳定性最好;蜡质玉米氧化淀粉的透明度最佳;乙酰化二淀粉磷酸酯马铃薯淀粉、羟丙基二淀粉磷酸酯蜡质玉米淀粉、羟丙基二淀粉磷酸酯木薯淀粉、预糊化羟丙基二淀粉磷酸酯蜡质玉米淀粉的凝沉性较强,而蜡质氧化淀粉几乎无凝沉性;乙酰化二淀粉己二酸酯木薯淀粉的凝胶强度最大;羟丙基二淀粉磷酸酯蜡质玉米淀粉的最高黏度值最大,消减值最大;乙酰化二淀粉磷酸酯玉米淀粉的糊化温度最高;乙酰化二淀粉磷酸酯玉米淀粉的冻融稳定性、凝沉性优于乙酰化二淀粉磷酸酯马铃薯淀粉,且凝胶强度较高;羟丙基二淀粉磷酸酯蜡质玉米淀粉的黏度明显高于羟丙基二淀粉磷酸酯木薯淀粉,而后者的冻融稳定性、透明度、凝沉性优于前者。     

低压等离子体处理对蜡质玉米淀粉性质的影响

采用低压等离子体对蜡质玉米淀粉进行改性。在等离子体处理时间为4 min,处理功率分别为100、200、300、400 W时,研究了蜡质玉米淀粉的红外光谱特性、交联度、糊化特性和流变学性质。实验结果表明:等离子体处理使蜡质玉米淀粉发生了交联反应,淀粉的储能模量增加,损耗模量基本不变,能形成弱凝胶;糊化难度增加,糊化温度升高。     

交联羧甲基复合变性木薯淀粉的制备及性质

本实验以木薯淀粉为原料,用环氧氯丙烷作交联剂,氯乙酸作羧甲基化试剂,合成了交联-羧甲基复合变性淀粉.采用铜盐沉淀法测其取代度,筛选出了交联-羧甲基复合变性淀粉合成工艺的最佳条件为:反应温度55"C,反应时间4h,配料质量比淀粉:氯乙酸:氢氧化钠=1.00:0.44:0.44;在此条件下台成的产品取代度(DC)为0.79.与原木薯淀粉相比,交联.羧甲基反应后产物黏度增大,膨胀凝固性、热稳定性、透明度得到改善,具有较强的环境适应性和良好的应用性能.红外光谱分析发现,在1008～1164cm-1的吸收峰强度加强,证实在淀粉中引入了羧甲基.DSC分析表明,交联.羧甲基淀粉有较高的糊化温度,且更易糊化.     

乌冬面专用变性淀粉及其结构表征

采用交联―酯化―预糊化复合变性制备乌冬面专用改性淀粉,并与木薯原淀粉、交联淀粉及交联―酯化淀粉进行比较。结果表明,交联淀粉偏光显微及颗粒形貌没发生明显变化,交联变性并未破坏淀粉结晶结构;交联―酯化淀粉颗粒出现粘连和聚集现象,部分颗粒表面出现凹陷和裂纹现象;红外光谱表明,交联―酯化―预糊化复合变性淀粉在1 728 cm–1、1 247 cm–1附近出现新的吸收峰,分子内引入乙酰基团,X–射线衍射光谱显示,交联―酯化―预糊化复合变性淀粉在5.6°和22°处衍射峰强度减弱,A型特征峰加强,结晶类型由"C"型向"A"型转变;交联―酯化淀粉经预糊化处理后,淀粉颗粒膨胀破裂,结晶结构受到彻底破坏,淀粉偏光十字消失,但预糊化处理未破坏淀粉分子化学键。     

野葛淀粉与木薯淀粉混粉理化特性分析

以野葛淀粉和木薯淀粉为原料,将木薯淀粉分别以10%、30%、50%和70%的质量分数掺入野葛淀粉。研究了原粉基本成分、原粉和混粉的结构、凝胶特性、抗氧化活性、热特性、冻融稳定性、消化特性、冲调特性。结果表明：随着木薯淀粉比例的增多,可以根据扫描电镜中的颗粒形状明显区别原粉及混粉,混粉平均粒径(10.68～13.05μm)均比野葛淀粉(9.47μm)高。野葛淀粉与木薯淀粉分别为C型及A型晶体结构,混粉后并未改变其结构及红外光谱图。混粉的糊化起始温度随添加量增加而显著升高(P<0.05),更难糊化。混粉抗氧化能力降低、多次冻融后趋于稳定、冲调黏度增大;混粉后硬度增大,最高达到2 410.46 g,质地硬化,凝胶性能变差;混粉的抗性淀粉(质量分数0.37%～1.59%)相对野葛淀粉较低(5.65%)。木薯淀粉的掺入对混粉影响较大,有利于从淀粉的结构和理化特性等方面为鉴别野葛淀粉中是否掺有木薯淀粉提供参考。     

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.     

肇实淀粉的光学性质及消化特性研究

研究了肇实淀粉的光学性质及消化特性。结果表明,肇实淀粉具有以下特性:偏光十字很明显,其交叉点位于淀粉颗粒中心;主要的近红外吸收峰位置与玉米淀粉、大米淀粉相同,但强度有差异;消化速率比玉米淀粉和大米淀粉低;糊化前后的抗性淀粉含量均比玉米淀粉和大米淀粉高;血糖生成指数低于玉米淀粉、大米淀粉及白面包。     

辛烯基琥珀酸淀粉酯的制备及黏度分析

分别制备了蜡质玉米辛烯基琥珀酸淀粉酯和马铃薯辛烯基琥珀酸淀粉酯,利用红外光谱分析仪分析了两种淀粉的结构特征;对比了两种淀粉酯化反应的取代度和反应效率,发现蜡质玉米淀粉酯比马铃薯淀粉容易酯化;运用Brabender黏度仪测定了不同取代度的两种酯化淀粉的黏度曲线.实验证明:两种淀粉酯化后峰值黏度升高,糊化温度降低,凝沉性下...     

Thermal, microstructural and textural characterisation of gelatinised corn, cassava and yam starch blends

The functional properties of mixtures of maize, cassava and yam starches and their relationships with microstructural characteristics were investigated. Experiments were performed following the simplex‐centroid design with internal points and restrictions (upper limit) for yam starch proportion. The statistical model used (Scheffé canonical equation) was a powerful tool to predict the pastes behaviour within the limits of the experimental area. Polynomials with second level interactions were applied to obtain the surface response. Viscoelastic attributes of mixtures differed from those of individual starches. As shown by differential scanning calorimetry and microscopical observations, physical properties of the mixtures depended on the type of networks obtained. These networks varied upon yam, corn and cassava starch proportions as each one has a particular characteristic: gelatinisation temperature, granule size, swelling capacity and amylose/amylopectin ratio among others.     

Gel Textural Characteristics of Corn,Cassava and Yam Starch Blends: A Mixture Surface Response Methodology Approach

Blends of native starches can be used to obtain special sensory properties avoiding the use of chemically modified starches. The mixture design approach was used to analyze the textural properties (hardness, adhesiveness, cohesiveness and gumminess) of gels obtained with different proportions of yam, corn and cassava starches (6% total solids) and related to microstructural characteristics. Maximum limits of 60% yam starch and 70% corn starch and minimum level of 30% cassava starch were fixed to minimize syneresis under storage. Hardness, adhesiveness and gumminess increased with the proportion of corn starch in the blends. The lowest values of hardness corresponded to the blends containing higher proportions of cassava starch, that has the lowest amylose content. Corn starch was the component that less contributed to cohesiveness. The characteristic high cohesiveness of cassava starch pastes (related to its higher amylopectin content) was reduced when it was mixed in adequate proportions with yam and/or corn starches. Gels containing only yam starch presented syneresis values close to 40% after 24° h storage at 4°C; the decrease of the maximum level of yam starch to 60% as well as the inclusion of cassava starch in the blends reduced weight losses. Disadvantages found in gels containing individual starches, such as exudate in yam and corn starch gels, and excessive cohesiveness in cassava starch gels, are minimized improving their possible applications, when blends are used.     

菠萝蜜种子淀粉消化特性与糊性质的研究

以菠萝蜜种子为原料提取淀粉,研究淀粉的消化特性以及糊性质。结果表明:菠萝蜜种子淀粉具有较低的消化性,抗酶解能力强;通过扫描电镜观察,发现α-淀粉酶作用不同的淀粉,其酶解方式不同,对菠萝蜜种子淀粉是通过淀粉表面进行侵蚀的作用方式酶解,而对于玉米淀粉则通过淀粉颗粒通道酶解颗粒内部;淀粉糊属于假塑性流体,其抗剪切能力比玉米淀粉,木薯淀粉强,其凝沉性比玉米淀粉小,比木薯淀粉大。     

淀粉原料3D打印特性

3D打印作为一种新兴的加工方法,在食品制造领域受到越来越多的关注。该研究以马铃薯、小麦和玉米淀粉为原料,对3D打印样品的特性进行了研究。采用外观形态、颜色、碘吸收光谱、快速黏度分析仪(rapid visco analysis,RVA)、质构分析、傅里叶变换红外光谱(fourier transform infrared spectroscopy,FT-IR)和扫描电镜(scanning electron microscope,SEM)对产品质量进行了评价。结果表明,所有淀粉凝胶均可获得完整的3D打印模型。用小麦淀粉制作的3D打印样品的尺寸最接近CAD设计模型。小麦淀粉凝胶具有较低的黏度、较好的挤出性和贮藏性能。此外,小麦淀粉制作的3D打印样品的微观结构比马铃薯淀粉和玉米淀粉具有更规则的网状结构。为3D打印技术在食品生产中的应用提供了理论依据,并为实际生产提供了技术支持。     

Relationship between thermomechanical properties and baking expansion of sour cassava starch (Polvilho azedo)

The factors involved in the baking expansion of native and sour cassava starch doughs were compared with those of native corn starch. Unlike corn starch dough, native and sour cassava starch doughs showed expansion properties during baking. The storage modulus E ′ decreased for cassava starch doughs before baking expansion, but remained unchanged for corn starch dough. Expansion during the baking of sour cassava starch was attributed to water vaporisation and the fluidity of starch paste. The fact that temperature and weight loss variations at adequate water contents were significantly greater for cassava than corn starch dough is indicative of the important role played by starch melting in expansion. Expansion ability could be correlated with changes in dough–crumb thermomechanical properties when close to the starch melting temperature. © 2001 Society of Chemical Industry     

杂粮淀粉在仔猪体内的消化率研究

以60 日龄生长猪为动物模型,考察4 种不同杂粮原料中淀粉(总淀粉、直链和支链淀粉、抗性和非抗性淀粉)的含量及其在生长猪回肠末端和粪中的表观消化率。结果表明：以干物质为基础,各种杂粮淀粉的含量因杂粮种属不同而差异较大。芋头淀粉和木薯淀粉的回肠末端消化率均显著高于(P ＜ 0.05)土豆和山药淀粉;所有淀粉在粪便中的表观消化率均达99% 以上。芋头淀粉和木薯淀粉因回肠末端消化率高而具有较高的葡萄糖供给效率,土豆淀粉和山药淀粉因后肠微生物的发酵而利用率升高。     

Isolation and physicochemical characterisation of starch from cocoyam (Colocasia esculenta) grown in Malawi

BACKGROUND: The aim of this study was to determine the physicochemical properties of starches isolated from Malawian cocoyams and compare them with those of cassava and corn starches. RESULTS: The purity of the isolated starches varied from 851 to 947 g kg^?1 and pH from 4.93 to 6.95. Moisture, ash, protein, fat and amylose contents ranged from 104 to 132, 0.3 to 1.5, 3.5 to 8.4, 0.9 to 1.6, and 111 to 237 g kg^?1, respectively. Cocoyam starches gave higher potassium and phosphorus but lower calcium levels than the other starches. The shape of starch granules varied from spherical to polygonal with cocoyam starches displaying smaller‐sized granules than cassava and corn starches. Cocoyam starches gave a higher wavelength of maximum iodine absorption and blue value but lower reducing capacity values than cassava and corn starches. The extent of acid hydrolysis of the starches also differed. Cocoyam starches exhibited amylopectin molecules of higher molecular weights but amylose molecules of lower molecular weights than cassava and corn starches. Cocoyam starches exhibited lower water absorption capacity and swelling power, paste clarity and viscosity but higher solubility, gelatinisation temperatures and retrogradation tendencies than cassava and corn starches. CONCLUSIONS: The physicochemical properties of native Malawian cocoyam starches vary among the different accessions and differ from those of cassava and corn starches. Copyright © 2010 Society of Chemical Industry     

紫山药淀粉与其抗性淀粉理化性质的比较

以紫山药淀粉为研究原料,采用不同方法分别制备压热、酶解-压热及双酶纯化抗性淀粉,分析比较了紫山药淀粉与其抗性淀粉的理化性质。试验结果表明:紫山药淀粉颗粒呈圆形或椭圆形且表面光滑;抗性淀粉颗粒破碎且呈不规则型。4种淀粉的化学结构相似,与原淀粉相比,抗性淀粉没有生成新的基团。抗性淀粉样品的凝沉速度随直链淀粉含量的增加而加快,冻融稳定性则降低;碘吸收曲线向支链淀粉吸收波长方向偏移。流变学分析表明与原淀粉相比抗性淀粉表观黏度均增大,剪切结构恢复力与抗性淀粉含量成反比。     

Influence of enzyme active and inactive soy flours on cassava and corn starch properties

The aim of this work was to study the influence of enzyme active and inactive soy flours on the properties of cassava and corn starches. Four starch/soy flour composites were evaluated: cassava/active soy flour (Cas/AS), cassava/inactive soy flour (Cas/IS), corn/active soy flour (Corn/AS) and corn/inactive soy flour (Corn/IS). Starch gelatinization occurred at 58.67°C for Cas and at 64.19°C for corn; gelatinization occurred at higher temperatures when soy flours were present, while ΔH diminished. The presence of AS reduced 80% the retrogradation enthalpy of Cas and 40% that of corn. Cas presented lower pasting temperature than corn starch (67.8 and 76.8°C, respectively) and higher peak viscosity (427.9 and 232.8 BU, respectively). The pasting properties of both starches were drastically reduced by soy flours, and this effect was more noticeable in Cas; AS had higher effect than IS. X‐ray diffraction pattern of retrograded samples showed that both starches recrystallisation (mainly that of Cas) was reduced when AS was added. Tan δ values decreased with AS addition to corn, but they increased when added to Cas. The images obtained using confocal laser scanning microscopy (CLSM) showed that IS was distributed as large aggregates, whereas AS distribution was more homogeneous, especially when incorporated to Cas. These results show that cassava starch interacts specifically with active soy flour (AS, mainly in native state). The delaying effect of AS on cassava starch retrogradation was clearly shown. This finding could be useful in obtaining gluten‐free breads of high quality and low retrogradation rate.     

菠萝蜜淀粉-月桂酸复合物的理化特性研究

淀粉与油脂热加工过程中会产生大量淀粉-脂质二元复合物,这会显著影响淀粉基产品的品质、保质期、物理化学特性等.菠萝蜜是新型小颗粒、直链淀粉含量高的热带特色淀粉资源.以木薯和玉米两种淀粉与菠萝蜜淀粉同为A型结晶的淀粉作参照,探究加热过程中菠萝蜜原淀粉与月桂酸形成复合物的复合指数、糊化特性、粒径分布、颗粒形貌和短程有序性.实...