不同糊化度籼米淀粉的结构及理化性质研究

本研究制备出糊化度分别为58%、80%、100%的籼米淀粉,探讨了糊化程度不同对籼米淀粉微观形貌、结晶特性、短程有序结构、层状结构及其热特性、黏度性质的影响。结构特性表明,随着糊化度的增加,籼米淀粉颗粒结构破坏程度加剧,双螺旋结构和分子有序排列被逐渐破坏,半结晶结构逐渐消失。热特性结果进一步证实,淀粉微晶结构随糊化度增加被破坏的程度加大,且不稳定的微晶优先被熔化使得剩余微晶的均匀性和稳定性有所提高。黏度性质表明,完全糊化籼米淀粉能在较低温度下吸水溶胀形成高黏度的溶液,但热糊稳定性差。尚余微晶结构的淀粉随糊化度的增加表现出更高的峰值黏度和更弱的热糊稳定性。     

Effects of Hydroxypropylation on Themal Properties,Starch Digestibility and Freeze-Thaw Stability of Field Pea (Pisum sativum cv Trapper) Starch

Field pea starch with an amylose content of 34.2% was hydroxypropylated with propylene oxide and sodium hydroxide to give products with molar substitutions (MS) ranging from 0.04 to 0.12. Increasing the degree of MS resulted in progressive decreases in enthalpy of gelatinization. gelatinization temperatures, pasting temperatures and syneresis. and increases in paste viscosities at 95 and 50°C. The digestibility with a-amylase decreased with increases in MS only up to the level of 0.08 and further increases in MS caused an increase in digestibility which was higher than that observed for native starch. These results were confirmed by scanning electron microscopy on hydrolyzed starch.     

Application of Differential Scanning Calorimetry to Amaranth Starch Gelatinization – Influence of Water,Solutes and Annealing

Gelatinization phenomena of amaranth starch were investigated using differential scanning calorimetry. Slight variations in onset (To) and peak (Tpl) temperatures were observed at moisture contents over 0.48 g water/g total. However, completion temperature (Tc) increased significantly. The intermediate transition temperature (Tp2) appeared at 0.61 g water/g total and below. The degree of gelatinization decreased by decreasing the moisture content. The three transition temperatures (To. Tpl and Tc) were increased and gelatinization delayed as the concentration of sucrose was enhanced. The three latter transition temperatures tended to increase as the sodium chloride was raised to 0.066 g/g total, but further increases in salt reduced significantly these temperatures. The gelatinization was delayed by increasing the salt concentration. After annealing for 12 h at 25 to 65°C, starch samples exhibited higher To and Tpl values, and narrowed gelatinization ranges. The degree of gelatinization augmented up to the annealing temperature of 55ºC and significantly decreased thereafter.     

青香蕉微波干燥中淀粉糊化行为及消化特性的研究

明确微波干燥(Microwave drying,MD)过程中青香蕉水分迁移与其淀粉糊化行为的关系及其对淀粉消化特性的作用,以青香蕉片为研究对象,设计不同微波功率密度,研究青香蕉MD干燥特性、淀粉糊化行为及消化特性的变化.结果表明微波功率密度和MD时间对青香蕉中淀粉糊化行为和消化特性影响显著.当青香蕉含水率高于45％,在...     

制备羧甲基淀粉的研究

羧甲基淀粉是重要的变性淀粉之一，用途广泛。本研究用乙醇溶剂法制备羧甲基淀粉。结果表明，增加一氯醋酸用量，降低淀粉乳浓度，能提高醚化取代度；氢氧化钠用量和水份含量对反应影响显著，选用适当的量能有效地促进醚化反应；在一定范围内，随着反应温度升高，反应时间延长，取代度随之增高。乙醇溶剂法能有效地抑制淀粉在反应过程中糊化，反应进行均匀，并且具有反应时间短、操作简单，易于控制，能制得高取代度、高质量产品等优点。     

Gelatinization Characteristics of a Cassava/Corn Starch Based Blend during Extrusion Cooking Employing Response Surface Methodology

The gelatinization characteristics of a cassava/corn starch based blend with relatively high moisture content during cooking extrusion were studied. The study was carried out by using Response Surface Methodology. The results showed that the die temperature T_d (°C) was the main influencing factor for the starch gelatinization, and the feed rate of the materials V_f (g/min) was another minor one. Because of the high material moisture content during extrusion the moisture content M_c (%) influenced the gelatinization degree not so obviously. The residence time distribution of the mass during extrusion were studied as well as discussed as a influencing factor on the gelatinization results.     

不同直链淀粉含量玉米淀粉挤出物的酶解力与糊化度研究

通过改变挤压机的系统参数(挤压机螺杆转速、套筒温度、喂入料水分含量),研究了系统参数对不同直链淀粉含量玉米淀粉挤出物酶解力与糊化度的影响,实验结果表明挤压机螺杆转速对玉米淀粉挤出物酶解力及糊化度的影响较小;套筒温度对玉米淀粉挤出物酶解力及糊化度的影响较明显,套筒温度为60 ℃时挤出物酶解力最高,普通玉米淀粉、高直链玉米淀粉、蜡质玉米淀粉三种挤出物的酶解力分别为1.102、0.948、0.926;喂入料水分含量对不同直链淀粉含量玉米淀粉挤出物酶解力及糊化度的影响最明显,随着水分含量升高,酶解力先增大后减小,喂入料水分含量为25.0%时不同直链含量玉米淀粉挤出物酶解力最大,普通玉米淀粉、高直链玉米淀粉、蜡质玉米淀粉挤出物的最大酶解力分别为0.862、0.948、0.861,同时糊化度呈下降趋势。这为研究不同直链淀粉含量玉米淀粉的应用提供一定的理论基础。     

食用碱对小麦淀粉特性及面条表面黏性变化的影响

为研究食用碱对小麦淀粉特性及面条表面黏性影响的变化规律,该研究采用低场核磁共振仪、快速粘度仪、质构仪等分别研究食用碱对淀粉糊化特性、凝胶特性以及面条表面黏性等的影响。研究表明随着食用碱添加量的增加,面团吸水率、强结合水含量呈升高趋势,淀粉糊化黏度值增大,衰减值、回生值减小。淀粉透明度、溶解度和膨润率不断提高,析水率逐渐降低。食用碱添加至0.4%时,淀粉的凝胶破裂强度降低至40.81%,凝胶破裂距离增加至17.99%,凝胶黏度增加至30.94%。食用碱的添加可显著降低面条的表面黏性。面条表面黏性与面团吸水率、强结合水含量、淀粉溶解度、凝胶破裂距离呈负相关,与淀粉冻融特性、回生值、衰减值呈正相关。食用碱提高了淀粉的糊化稳定性、凝胶弹性以及冻融稳定性,降低了面条的粘连程度。     

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。     

水分、温度、时间和pH对板栗淀粉颗粒形态的影响

以安徽大红袍板栗为原料,采用光学显微镜分析其在不同水分、温度、时间和pH条件下表观形态的变化.结果表明:随着淀粉体系中水分含量的升高,板栗淀粉颗粒越易膨胀破裂,水分含量达到70%后,大部分淀粉颗粒膨胀:加热温度和加热时间都能促进板栗淀粉颗粒膨大破裂,而加热温度对颗粒形态变化的影响较加热时间大;常温下中性和酸性条件对板栗淀粉颗粒膨胀的影响不大,而强碱性条件对板栗淀粉糊化有明显的作用,当pH达到13时,淀粉颗粒明显膨胀.     

不同糊化度苦荞粉理化性质和体外消化性的研究

以苦荞全粉和芯粉为原料,通过挤压膨化制备不同糊化度(61.27％～97.65％)的苦荞粉样品,对其理化特性及体外消化性进行研究.结果表明:随着糊化度的增大,苦荞粉的水分、脂肪及黄酮含量显著降低(P＜0.05);粒径、吸水性指数、水溶性指数及膨胀度显著增大(P＜0.05);快速黏度分析结果表明高糊化度苦荞粉的峰值黏度、谷...     

PHYSICOCHEMICAL CHANGES IN STARCH DURING DEEP-FAT FRYING OF A MOLDED CORN STARCH PATTY

Corn starch patties with an initial moisture content of 46.5% (wet basis) were fried in oil at 165C. The results indicated that oil content in the patty ranged from 10.6 to 12.5% in the crust region, and 1.5 to 3.9% in the core region. Starch gelatinization was significantly dependent on frying time and location of starch in the patty. Both, water absorption and water solubility indices of starch increased with frying time, with the starch contained in the crust exhibiting much higher water absorption ability and water solubility than that contained in the core region. Measurements of 'blue value'(the intensity of blue color of starch solution upon addition of iodide ion) and the absorbance spectra of starch samples indicated that amylose-lipid complexes were present in the fried materials. The degree of starch complexation was 10.9 to 13.2% in the crust and 0.3 to 6.6% in the core region. The puncture force on the surface of a food fried for no more than 5 min was close to that in the food center, although a significant increase in force was required for the crust region during the later stages of frying.     

冻融循环下抗冻多肽对冷冻马铃薯面团的品质保护及作用机理

通过将抗冻多肽添加到马铃薯面团中,研究在冻融循环条件下抗冻多肽对冷冻马铃薯面团品质的保护作用。在冻融循环条件下测定抗冻多肽（tilapia scale antifreeze peptides,TSAPP）对冷冻马铃薯面团的比容、发酵性能、失水率、淀粉糊化度、质构特性、水分分布与迁移等的影响及作用机理。结果表明：添加1% TSAPP使马铃薯面团比容增大、发酵时间缩短、淀粉糊化程度高、失水率降低;质构分析显示,与空白对照组相比,1% TSAPP组的马铃薯馒头硬度、咀嚼性和胶黏性分别下降了29.96%、26.99%、28.30%;核磁共振分析显示,TSAPP可以影响冷冻马铃薯面团中的水分状态使深层结合水含量增加,半结合水含量减少;TSAPP还能抑制水分流失,提高马铃薯面团的持水力。结论：抗冻多肽可作为冷冻马铃薯面团产品的低温保护剂。     

挤压糊化处理对苦荞粉理化性质的影响

为研究挤压糊化处理对苦荞粉理化性质的影响,利用单螺杆挤压机对苦荞粉进行挤压糊化处理,得到糊化 度分别为37.7%、56.3%、74.3%及94.2%的苦荞粉,并对其基本成分、水合特性、糊化特性、热力学特性及微观结 构进行测定。结果表明：随着糊化度增加,淀粉、蛋白质及灰分质量分数总体无显著变化（P＞0.05）,总黄酮和 脂肪质量分数显著减少（P＜0.05）,颜色变深;破损淀粉质量分数、吸水性指数及保水性显著增加（P＜0.05）; 快速黏度分析结果表明挤压处理苦荞粉峰值黏度、谷值黏度、最终黏度、回生值下降,峰值时间缩短;扫描电子显 微镜结果表明,苦荞粉颗粒为圆形或不规则多边形,而挤压糊化处理后苦荞粉颗粒没有固定形态,表面粗糙且有裂 纹和小孔。上述理化性质的研究可为进一步的机理及应用研究提供参考。     

热烫温度对小麦面团介观特性的影响机制

本实验以热烫面团为研究对象,通过凯氏定氮法、粒径分析、傅里叶变换红外光谱以及快速黏度分析等手段,研究55、65、75、85℃和95℃热烫温度下小麦面团中麦谷蛋白大聚体的质量分数、粒径分布、蛋白质二级结构以及面团中淀粉的糊化特性的变化情况.结果表明:随着热烫温度的升高,面团中麦谷蛋白大聚体质量分数呈现显著增大的趋势(P<...     

部分糊化玉米淀粉浆液的性能

以玉米淀粉为原料,采用蒸汽升温法制备部分糊化淀粉浆液。运用光学显微镜、粒度分析仪、差示热分析仪、X射线衍射仪等对原淀粉和用蒸汽升温法于不同温度下制备的部分糊化淀粉浆液的形态结构、颗粒大小、膨胀势、糊化度、结晶度等进行了测试和比较。结果表明:随着制备温度的提高,部分糊化淀粉浆液的偏光十字逐渐消失,结晶度下降,而糊化度、粒径、膨胀势逐渐增大;64℃时制备的稳定性较好的部分糊化淀粉浆液的大部分偏光十字消失,但仍有结晶峰存在,糊化度为72.22%。     

A Study on Degree of Starch Gelatinization in Cakes Baked in Three Different Ovens

The main objective of the study was to determine the effects of different baking ovens and different cake formulations on the degree of starch gelatinization during cake baking. Baking was performed in microwave, infrared–microwave combination, and conventional ovens. Starch gelatinization levels of fat free, 25% fat, and 25% Simplesse™-containing cake samples were examined using differential scanning calorimeter (DSC) and rapid visco analyzer (RVA). Both DSC and RVA results showed that increasing baking time increased gelatinization level for all baking types significantly. It was also found that the effect of fat content on starch gelatinization was different depending on the type of baking. Addition of fat reduced the degree of starch gelatinization in conventional baking. However, fat enhanced the gelatinization in microwave and infrared–microwave combination ovens. Usage of Simplesse™ as a fat replacer decreased the starch gelatinization in all types of baking significantly. There was insufficient starch gelatinization in microwave-baked cakes in which the degree of gelatinization ranged from 55% to 78% depending on formulation. On the other hand, it ranged from 85% to 93% in conventionally baked cakes. Combining infrared with microwaves increased degree of starch gelatinization (70–90%).     

Hydrothermische Behandlung von Stärke in Gegenwart von Maltosesirup. Teil 1. Einfluß auf DSC-Parameter und die Konsistenz von Kartoffelstärkegelen

Hydrothermal treatment of starch in presence of maltose syrup. Part 1. Effect on DSC Parameters and consistency of potato starch gels A hydrothermal modification of potato starch at water excess in presence of maltose syrup permits distinct changes of properties as paste consistency, gelatinization and gelation behaviour preserving the granular structure at the same time. Annealing in maltose syrup causes a drastic decrease in hot past consistency and an increase in consistency during the keeping phase at 96°C. 3.3% starch in pastes of such samples produces a set back of about 2300 BU at a Brabender final temperature of 50°C. Annealing of potato starch in maltose syrup doubles Brabender final consistency with minimal loss in yield (< 10%). Modified patterns show a gel elasticity of about 20%-sag measured in ridgelimeter. Gel bevels composed of 3.3% annealed starch modified in 6%ical maltose syrup up to a final temperature of 56°C are characterized by sag values of 17%. The alkaline stability measured in Brabender viscograph rises 4 fold in these samples and show a shift of the DSC swelling temperature T_max of 5.5 to 8 K. Annealing of potato starch in maltose syrup makes it possible to alter properties within a short time at very low energy consumption offering broad industrial application.     

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。     

羟丙基糯玉米淀粉合成工艺及性能研究

本文以糯玉米淀粉为原料，以环氧丙烷为醚化剂、氢氧化钠为催化剂、硫酸钠为抑制膨胀剂，对糯玉米羟丙基淀粉合成工艺及其性能进行了研究，探讨了糯玉米淀粉乳浓度、环氧丙烷用量、反应时间、反应温度、氢氧化钠用量及硫酸钠用量对糯玉米羟丙基淀粉取代度和反应效率的影响。实验结果表明，增加环氧丙烷用量、延长反应时间，可使羟丙基淀粉取代度增加。对糯玉米羟丙基淀粉的冻融稳定性、透明度及粘度进行研究表明，随着羟丙基糯玉米淀粉取代度的增加，其冻融稳定性和透明度增加，但粘度却降低。