糊化条件对淀粉溶解度及性能的影响

考察了原淀粉和变性淀粉的取代度、糊化温度与时间和添加NaOH等糊化条件对淀粉溶解度的影响。并解析了溶解度与淀粉作用效果的关系。研究结果表明，糊化温度越高，淀粉的溶解度越大，糊化温度应在90~C以上。淀粉才能充分溶解；添加NaOH加速淀粉的糊化速度；变性淀粉的取代度和制备条件对其溶解度均有较大影响；延长糊化时间可提高阳离子淀粉的作用效果，而加碱糊化会降低阳离子淀粉的作用效果。     

Solubility Pattern and Recrystallization Behavior of Oat Starch

The oat starch studied had a lipid content of 1,3% and amylose content of 29%. Based on the colorimetric assay, only 15% of the starch leached out from the native granules at 95°C was amylose, whereas 85% of the starch leached from the defatted granules was amylose. The solubilized amylopectin-type material of native oat starch was of clearly lower molecular weight than most of the amylopectin in the original starch. The amylopectin recrystallization enthalpy of 50% native oat starch dispersion Id after gelatinization was 2J/g and that of defatted oat starch was 4J/g.     

Gelatinization Properties of Navy Bean Starch

Gelatinization properties of navy bean (Phaseolus vulgaris) starch under different combinations of concentration (6, 8, 10 and 12%) and cooking temperature (75, 85 and 95°C) were studied using a rotational viscometer. The torque response due to swelling and/or breakdown of starch granules approached equilibrium after either a gradual increase or a relatively rapid increase to a peak followed by a decline during cooking. For every condition, the difference between the final torque values obtained for the rapid and the slow heating processes was not significant. In general, the viscosity of the paste increased as the starch concentration and/or cooking temperature increased. However, cooking temperature of 75°C did not cause a significant gelatinization or swelling of starch granules in pastes of 6 or 8% concentration. Maximum final viscosity values were obtained at 85°C for all starch concentrations except for a maxium at 95°C for 6%. Thixotropic breakdown was observed at 10 and 12% concentrations during initial shearing at 85 and 95°C. The threshold concentration for singnificant viscosity effects in this study was in the range of about 8 to 10% or 95°C. The calculated activation energy (14.5 Kcal.g⁻¹ mole⁻¹) of navy bean starch gelatinization was similar to values reported for rough rice and rice starches.     

Gelatinization Properties of Chinese Water Chestnut Starch and Lotus Root Starch

A microscope heating-stage and differential scanning calorimetry were used to characterize the gelatinization of lotus root starch and water chestnut starch. The effect of varying concentrations of different sugars on gelatinization temperature was also studied.     

Physicochemical Properties of Defatted Oat Starch

Three Polish varieties of oat starch were subjected to defatting by a cold extraction with the chloroform-methanol-water (3:2:1) mixture followed by a hot extraction with 1-propanol. A comparison of results allowed discussion of the effectiveness of the extraction procedures, their effect on the structure of original starch as well as the structure of oat starch-lipid inclusion complexes.     

Gelatinization of Starch and Modified Starch

Gelatinization temperatures of starch and hydroxyethyl starch was determined using Differential Scanning Calorimetry (DSC), hot stage microscopy and viscography. The gelatinization temperature based on peak temperature of DSC is incorrect. Viscograph overestimates the gelatinization temperature. Hot stage microscopy based on visual observation gives the correct gelatinization temperature. DSC gives the heat of gelatinization which is helpful in estimating heat requirement during cooking of starch. Hydroxyethylation of starch reduces gelatinization temperature and heat of gelatinization for starch.     

小麦淀粉与马铃薯淀粉、豌豆淀粉共混物的糊化与凝胶特性

研究了小麦淀粉分别与马铃薯淀粉、豌豆淀粉以不同比例混合后淀粉混合物的糊化特性、流变学特性和凝胶特性等。结果表明：小麦淀粉的峰值黏度（2 430.50 Pa•s）等糊化特性参数低于马铃薯淀粉（9 001.02 Pa•s）和豌豆淀粉（2 644.50 Pa•s）,而糊化温度（90.70 ℃）高于马铃薯淀粉（67.05 ℃）和豌豆淀粉（73.95 ℃）。两种混合淀粉体系的糊化特性值在小麦淀粉和马铃薯淀粉、小麦淀粉和豌豆淀粉的值之间发生变化。凝胶的质构和水分子状态等参数有相似的特性变化规律。小麦淀粉的模量（G′为4 770.85 Pa、G″为453.80 Pa）高于马铃薯淀粉（G′为1 392.46 Pa、G″为175.65 Pa）和豌豆淀粉（G′为3 256.89 Pa、G″为275.36 Pa）,两种混合淀粉体系的储能模量和损耗模量在小麦淀粉和马铃薯淀粉、小麦淀粉和豌豆淀粉的值之间发生变化。马铃薯淀粉（7.84 J/g）和豌豆淀粉（8.18 J/g）的热焓值小于小麦淀粉（13.06 J/g）,小麦与马铃薯混合淀粉、小麦与豌豆混合淀粉热焓值降低。综上所述,小麦淀粉分别与马铃薯淀粉和豌豆淀粉混合使得混合淀粉的性质发生不同程度的改变,可为淀粉的天然改性提供一定的理论依据。     

交联酯化淀粉糊化性质的研究

以木薯淀粉为原料,利用醋酸酐与己二酸的混合酸酐制备了乙酰化双淀粉己二酸酯。利用Brabender黏度计,通过不同的测试方法,评价了样品的糊化性质。结果表明:同一样品在不同测试温度下,样品的糊化温度没有明显变化,但是糊化过程中黏度差异性较大;而两样品在不同糊化测试温度下表现出了不同的差异性;随着测试温度的提高,样品的峰值黏度呈下降趋势,回升值呈上升趋势。样品在1.5℃/min升温速度条件下的糊化温度低于在3℃/min条件下的;随着升温速度的提高,样品在冷却阶段结束时的黏度和回升值均呈下降趋势。在250 r/min条件下,样品的黏度显著高于在75 r/min条件下的;在250 r/min条件下,在95℃保温阶段,样品的黏度呈下降趋势。     

纳米纤维素对小麦淀粉糊化和流变特性的影响

将不同比例微晶纤维素(microcrystalline cellulose,MCC)、纳米晶体纤维素(nanocrystaline cellulose,NCC)、纳米纤化纤维素(nanofibrillated cellulose,NFC)与小麦淀粉(wheat starch,WS)复配,对比研究纳米纤维素对小麦淀粉糊化...     

淀粉纳米颗粒在不同增塑剂中的糊化与流变特性研究

本文以蜡质玉米淀粉为原料,经普鲁兰酶酶解脱支,短直链淀粉重结晶制取淀粉纳米颗粒(SNPs)。采用差示扫描量热仪(DSC)和动态流变仪,探究了不同浓度SNPs在甘油、山梨糖醇、葡萄糖水溶液中的热特性、回生特性以及流变特性的变化规律。DSC测试表明,添加山梨糖醇、葡萄糖和甘油溶液(其与水比例为1:1)后,SNPs的起始糊化温度分别增加了10.85℃、10.96℃和15.02℃,SNPs的终止糊化温度分别增加了9.29℃、9.17℃、12.40℃。回生结果表明,增塑剂会抑制SNPs的回生。随着浓度增加,SNPs在增塑剂体系中储能模量明显增加,且损耗模量大于储能模量,凝胶性增强。20%SNPs在山梨糖醇溶液和甘油溶液中的储能模量是10 Pa·s左右,而在葡萄糖溶液中大于1000 Pa·s,在葡萄糖溶液中损耗模量在100~500 Pa·s,说明SNPs葡萄糖水溶液具有更强的凝胶性。本文为SNPs在不同增塑剂中制备可降解膜提供理论依据。     

高直链玉米淀粉的糊化特性研究

目的研究水浴加热、微波加热和高压加热方法对高直链玉米淀粉糊化性能的影响,为高直链淀粉的进一步开发和应用提供理论基础。方法以高直链玉米淀粉为原料,在过量水分存在条件下,分别采用水浴加热、微波加热和高压加热制备高直链玉米淀粉糊,分别研究不同温度和微波功率下,高直链玉米淀粉糊碘兰值和酶解力随糊化时间增加的变化规律。结果水浴加热、微波加热和高压加热糊化过程中高直链玉米淀粉的碘兰值和酶解力均随时间的延长呈上升趋势,微波加热高直链玉米淀粉糊的碘兰值和酶解力低于高压加热但高于水浴加热,微波加热淀粉的糊化速度大于水浴加热和高压加热。结论高压加热淀粉糊化效果好,淀粉的糊化程度高,是使高直链淀粉完全糊化的较好方法。     

辛烯基琥珀酸淀粉酯的制备与糊化性质研究

研究了以均匀设计的方法,在水相中制备不同取代度的辛烯基琥珀酸酸淀粉酯,以取代度为衡量指标,得到的最优组合为:温度31.4 ℃、OSA用量8.91%,淀粉乳浓度29%,pH值8.7,反应时间8.4 h,并对其糊化性质进行研究.     

薏米淀粉的结构表征与糊化特性研究

旨在阐明薏米淀粉的结构和糊化特征,为薏米食品开发和品种改良提供理论支撑。以6份薏米为试验材料,在粳（非糯）、糯性鉴定的基础上比较了不同胚乳类型薏米淀粉在淀粉粒度、分子量、链长分布、结晶度及糊化热力学等结构和理化特征。碘试剂染色和淀粉含量结果显示,3份糯性材料的胚乳染色呈棕红色,直链淀粉含量为1.54%～2.34%;非糯薏苡胚乳染色呈蓝色,直链淀粉含量为9.55%～22.92%,而且粳、糯性性材料之间均差异显著。淀粉颗粒扫描电镜和粒度分析结果表明,粳、糯性薏苡淀粉颗粒排列的紧实度存在品种差异,但是淀粉颗粒形貌相似,主要呈多面体和球形,外表往往具小孔、空腔或凹陷;粒径范围为4.03～35.3 μm,重均分子量(Mw)、流体力学半径(Rw)分别为80254.8～159438.4 kDa和122.3～233.7 nm;淀粉链长呈单峰分布,B1链数量占绝对优势,平均聚合度为17.17～17.53。6份薏米淀粉在X射线衍射角（2?）15°、17°、18°和23.5°均出现强衍射峰,其晶体类型均为A型,而且粳性薏米的淀粉结晶度显著高于糯性薏米;在近红外光谱波数（cm-1）995、1022、1045和1047处均有吸收峰,以QY02的1 045 cm-1/1 022 cm-1比值最高。薏米淀粉的糊化焓、起糊温度、衰减值和回生值范围分别为9.582～11.210 (J/g)、 78.95～79.85 ℃、450.00～1071.00 cP和121.00～ 912.00 cP,相比之下,糯性薏米淀粉比粳性薏米淀粉更易糊化但是却不易老化。     

稻米淀粉期化进程研究

对不同初始粒径的稻米淀粉的糊化进程进行了研究。结果表明,淀粉的糊化具有上升,平缓和回落三个除段,在糊化温度以下（60℃）,淀粉颗粒仅存在吸水膨胀,糊化度曲线平坦,糊化温度以上,随加热温度和的升高,淀粉的糊化速度和糊化程度迅速增高,明显开成糊化过程的三阶段,较小的初始粒径会加快糊化进程,增大回落程度,但对糊化程度影响不大,加热温度对糊化特性的影响较淀粉的初始粒径大。     

发芽燕麦淀粉的热特性

发芽是进一步提升谷物种子营养价值的重要手段,已经成为当前谷物研究的新热点。本文以晋燕八号燕麦为原料,通过在16℃浸泡并避光发芽,分别提取不同时间段的燕麦淀粉,用差示扫描量热(differential scanning calorimetry,DSC)和热重分析(thermogravimetric analysis,TGA)两种手段对原燕麦和发芽后燕麦淀粉的热特性进行表征。结果发现,发芽对燕麦中淀粉的起始糊化温度影响不大,在发芽144 h内,平均起始糊化温度为57.44±0.48℃,但发芽72 h以后的燕麦中淀粉糊化温度范围扩大,以发芽72 h为界,前后两段的糊化焓都是逐渐增加的,这可能提示发芽期间淀粉结构存在由无序到有序的交替变化过程;氮气氛围下,淀粉的分解温度在275~363℃之间,此温度区间内淀粉的质量损失为65%~73%;发芽淀粉热分解反应活化能比原燕麦淀粉均有降低,其中原燕麦淀粉的热分解活化能为219.44±14.46 kJ/mol,活化能最小的为发芽144 h的淀粉,其值为157.75±5.58 kJ/mol,各发芽阶段淀粉热分解反应级数均为一级。     

Gelatinization of Dieffenbachia Starch

The starch grain of Dieffenbachia seguine has the shape of an elongated, flat rod, one of whose ends is rounded and the other square. Its hilum lies near the rounded end of the grain. The molecules of the central core are parallel to the long axis of the grain while those of the peripheral layer tend to be nearly perpendicular (radial) to that axis. Gelatinization makes evident a fibrillar construction in which the fibrils of the core region are elongated parallel to the long axis of the grain while those of the periphery are crossed, at a low angle to the perpendicular. Presumably the heated starch molecules contract along their long axis, becoming randomly coiled, and thereby cause radial expansion in the core and axial and tangential expansion at the periphery of the starch grain.     

Cold Gelatinization of Starch

The cold gelatinization of starch and the subsequent leaching with water has been studied by a spectrophotometric difference method. It has been proved that the gel formation can only take place if amylose has first leached out of the starch granules and that amylopectin is the predominant gel forming component of starch.     

马铃薯淀粉糊化和凝胶特性与马铃薯粉品质的关系

为了研究马铃薯粉生产过程中原料淀粉的糊化和凝胶特性对马铃薯粉品质的影响,通过快速黏度分析仪和质构仪对6种不同的马铃薯淀粉的糊化和凝胶特性进行了测定,并对这些特性之间的关系,以及这些特性与马铃薯粉品质之间的关系进行了探讨。结果表明:马铃薯淀粉的糊化特性和凝胶特性之间存在密切关系,且糊化和凝胶特性与鲜湿马铃薯粉品质密切相关。淀粉的糊化特性与马铃薯粉的感官品质和断条率存在显著关性,按显著程度(r值大小)排序依次是:回生值谷值黏度峰值黏度最终黏度崩解值糊化温度。淀粉的凝胶特性对马铃薯粉的感官品质和断条率存在显著相关性,按显著程度(r值大小)排序依次是:咀嚼性凝胶强度、黏性硬度回复性弹性。在鲜湿马铃薯粉的生产过程中,可以采用马铃薯淀粉的回生值、凝胶的咀嚼性、黏性和凝胶强度作为原料的衡量标准。本研究为马铃薯粉生产的原料选取和品质改善提供了理论参考。     

不同糊化度马铃薯淀粉的黏度及凝胶特性分析

为探究不同糊化度马铃薯淀粉黏度及其凝胶特性的差异,本研究将马铃薯淀粉乳(料液比1:9)分别置于59℃和60℃条件下加热1、3、6、9、12、15、18 min,制备出糊化度为38.70%～91.13%的马铃薯淀粉样品。测定了不同糊化度马铃薯淀粉的黏度,微观结构,凝胶强度及弹力,并分析了马铃薯淀粉理化特性与其糊化度的相关性。结果表明,随水热处理温度升高和时间延长,马铃薯淀粉颗粒逐渐破裂,椭圆形特征形貌逐渐消失。马铃薯淀粉黏度,凝胶强度及弹力与其糊化度有显著的线性相关性(p0.01)。随糊化度的增大,预糊化马铃薯淀粉黏度由0.17m J增加至3.40m J。未经二次加热的不同糊化度马铃薯淀粉凝胶强度和弹力随初始糊化度的增大而显著增大,但经二次加热完全糊化的马铃薯淀粉凝胶的强度和弹力随初始糊化度的增大而显著降低。不同程度的预糊化处理显著改变了马铃薯淀粉的黏度及凝胶特性。     

兰州拉面对淀粉糊化特性的要求

用8个小麦品种(系)粉样和7个商品面粉样品研究了兰州拉面品尝评分与淀粉糊化指标之间的关系，结果表明：兰州拉面加工品质好的面粉具有以下特征：峰值粘度、最低粘度、衰减值、最终粘度和回生值都应较高，糊化温度应较低。其中面条评分与峰值粘度(r=0．593^*)、最低粘度(r=0．530^*)、衰减值(r=0．528^*)、最终粘度(r=0.531^*)的偏相关达到显著水平。通过二次曲线回归预测确定出兰州拉面专用粉主要糊化特性指标为：峰值粘度≥225RVU；低谷粘度≥150RVU；衰减值≥85RVU；最终粘度≥240RVU。