糯小麦“山农糯麦1号”籽粒及淀粉品质分析

为更好地了解糯小麦的品种特性,以山东省第一个审定的高产糯小麦“山农糯麦1号”为材料,研究其籽粒和淀粉特性。结果发现：该品种几乎不含直链淀粉（仅0.1%）,较普通小麦具有较高的蛋白质含量（16.4%）和面粉白度（81.2%）。扫描电镜观察淀粉粒度分布不均匀,A型淀粉颗粒较多。快速粘度分析（RVA）测定表明淀粉具有较低的糊化温度,较短的糊化时间,较低的峰值黏度、最终粘度和回生值。加工时面团吸水率明显较高,形成时间大于稳定时间。这些结果将为山农糯麦1号适于用作配粉和加工食品提供参考依据。     

糯小麦淀粉糊化黏度特性的研究

糯小麦淀粉中直链淀粉含量极低(＜1%),是一种新的天然淀粉资源.研究了糯小麦淀粉的糊化黏度特性,并将其与几种常用工业淀粉进行比较,结果表明:糯小麦淀粉品质优良,表观黏度值适中,具有一定的抗剪切能力,具有很强的抗酸黏度稳定性,这为糯小麦淀粉的工业应用提供了理论基础.     

糯小麦粉与普通小麦粉配粉糊化特性的研究

选用糯小麦品种中糯一号与普通小麦(非全糯小麦)品种豫麦47、温6和澳大利亚优质面条小麦品种Gamenya,进行籽粒蛋白质含量、淀粉含量及直链淀粉含量的测定。并将中糯一号面粉分别与豫麦47、温6面粉配粉,进行了RVA试验(快速粘度分析),研究了三种单一品种面粉及其配粉的糊化特性。结果表明:中糯一号籽粒蛋白质含量、淀粉含量与供试普通小麦品种相近。但其直链淀粉含量很低,仅为1. 45%,远低于供试普通小麦品种。在RVA试验中,中糯一号面粉糊化快,峰值时间比普通小麦缩短了一半,其粘度下降到低谷后,粘度曲线变化平缓,回冷值很小,明显与供试普通小麦不同。糯小麦与普通小麦配粉的粘度曲线呈双峰状,其粘度参数因糯、普小麦配粉比例不同而不同。总之,在普通小麦粉中加入糯小麦粉后,面粉直链淀粉含量和糊化特性发生了变化,对面制食品品质将产生一定的影响。     

紫糯麦淀粉理化特性研究

以紫糯麦168为原料提取紫糯麦淀粉。对其理化特性研究表明:紫糯麦淀粉有较低的直链淀粉含量和较高的相对结晶度,呈现典型的A型结晶特征;紫糯麦淀粉糊的透明度为22.57%,膨胀度和溶解度随温度的升高均增大;在贮藏期间上清液体积增加缓慢;经2次冻融循环后表现出较好的冻融稳定性;紫糯麦淀粉糊有高的峰值黏度和崩解值,较低的回生值和糊化温度。     

糯小麦粉配粉理化特性及其对馒头品质的影响

糯小麦粉由于直链淀粉含量很低而被赋予其独特的理化性质.采用糯小麦品种(中糯一号)制粉并与非糯小麦粉(农大393)配粉,对糯小麦粉及配粉的理化特性及对馒头品质和延缓老化等影响进行了研究.结果表明,与常规小麦粉相比,糯小麦粉直链淀粉含量仅为1.45%,与非糯小麦粉配粉能显著地改变面团的流变学特性和糊化黏度特性:面团的吸水率提高;面筋强度降低;RVA黏度试验中,各项黏度参数除糊化温度外均显著地降低.添加15%的糯小麦粉能显著地改善馒头的表皮结构、内部结构、表皮色泽和综合评分,15%～20%的糯小麦粉添加比例能有效地延缓馒头的老化.此外,直链淀粉含量,直/支淀粉含量比值,面粉的RVA黏度特性各项参数(糊化温度和峰值时间除外),面团的各项粉质仪参数(弱化度除外),吹泡参数中吹泡韧性P和拉伸比值P/L和面筋指数均是影响馒头老化速率的重要的影响因子.     

糯性普通小麦的籽粒成分和淀粉品质研究

对5个组合的13个糯麦F6（或F5）株系及其亲本的籽粒成分，直链淀粉含量和膨胀势进行测定，以及分析了它们的淀粉糊化过程和糊化参数，比较它们之间的差异。结果表明：糯性小麦籽粒的蛋白质含量，湿面筋含量均高于相应的亲本，而淀粉含量则低于相应的亲本，糯性小麦株系的直链淀粉含量远远低于其亲本；糯麦淀粉的膨胀能力和吸水力大于其亲本；糯麦株系的RVA高峰粘度，低谷粘度，最后粘度，反弹值和峰值时间显著低于其亲本。糯麦株系面粉间的RVA粘度参数值大同小异，讨论了糯性小麦的应用前景。     

不同筋力面筋蛋白对小麦淀粉糊化特性的影响

以3个不同小麦品种淀粉(2个普通小麦,1个糯性小麦)为实验材料,添加3种类型的面筋蛋白(强筋、中筋和弱筋),5个添加量处理(8%、10%、12%、14%、16%),分析淀粉和面筋种类及其交互作用对淀粉糊化特性的影响。结果表明:淀粉是糊化特性的决定因素,面筋蛋白质直接或通过淀粉交互作用显著影响糊化特性。淀粉和面筋蛋白类型交互作用对峰值黏度、黏度面积、稀懈值、糊化起始时间有极显著影响;淀粉和面筋蛋白含量的交互作用对除了糊化温度和糊化起始时间外的其他糊化指标都有极显著或显著的影响;面筋蛋白类型对稀懈值影响按其降低作用大小的顺序为:弱筋>中筋>强筋;面筋蛋白添加量对淀粉稀懈值和反弹值的影响因淀粉种类的不同呈现显著差异。     

小麦淀粉生产工艺因素对淀粉糊化特性的影响

研究小麦淀粉生产工艺因素中乳酸、焦亚硫酸钠、α-淀粉酶以及提取工艺对淀粉糊化特性的影响。结果表明,小麦淀粉中乳酸含量达到69.2 mg/kg,峰值黏度、回生值分别降低了42.1%和100%。焦亚硫酸钠对小麦淀粉糊化特性的影响和添加乳酸相似,含量达到3.3 mg/kg时,峰值黏度、回生值分别下降了18.0%和18.9%。小麦淀粉中α-淀粉酶活性达到123.1 U/100 mL时,峰值黏度、回生值分别降低了45.7%和97.0%。提取工艺中旋流法和卧螺法对小麦淀粉糊化特性影响差异不明显,但马丁法小麦淀粉谷值黏度、最终黏度明显低于旋流法和卧螺法淀粉。因此,减少杂菌感染产酸,适量添加焦亚硫酸钠以及尽量避免使用α-淀粉酶活性高的新小麦或发芽小麦制粉,有利于解决小麦淀粉在应用中出现的粘连、凝胶强度不够等问题。     

糯玉米粉、淀粉和脱脂淀粉的理化特性研究

以4个糯玉米品种为材料,比较分析了糯玉米粉、淀粉(脱蛋白)和脱脂淀粉(脱蛋白脱脂)的理化特性.结果表现,脱蛋白或脱蛋白脱脂处理不改变材料的结晶类型,各材料均表现为典型的"A"型衍射图谱.理化特性在糯玉米粉、淀粉和脱脂淀粉间存在显著差异.结晶度、膨胀势、回复值、峰值时间和糊化温度以糯玉米粉最高,脱脂淀粉最低;溶解度、峰值黏度和谷值黏度以淀粉最高,米粉最低;透光率以脱脂淀粉最高,米粉最低;但4个糯玉米品种的终值黏度变化趋势不甚明显.     

萌动小麦生化指标及Mixolab糊化特性的变化

分析了萌动小麦游离氨基酸、蛋白质、水溶性糖类和破损淀粉含量及Mixolab面团糊化特性的变化。小麦萌动后游离氨基酸总量显著增加,蛋白质含量(干基)也增加,Mixolab仪测定的C2稠度谷值、C3淀粉糊化黏度峰值、C4淀粉糊化黏度谷值、C5淀粉回生终点值均减小。小麦萌动前后,水溶性总糖含量、Bacillus amyloliquefaciens蛋白酶(含内切和外切酶)降解产生的游离氨基酸含量对试验的6个品种差异不显著;除1个品种外,试验的其他5个品种水溶性还原糖含量及Aspergillus melleus蛋白酶(仅含内切酶)酶解产生的游离氨基酸含量显著增加。不同品种小麦萌动前后破损淀粉含量增减不一致。结论为小麦发芽后游离氨基酸总量增加、Mixolab面团蛋白质网络弱化程度加大、淀粉糊化峰值和谷值均降低,可以作为芽麦检测的参考依据。     

Prediction of the degree of starch gelatinization in wheat flour dough during microwave heating

In order to produce quick-boiling noodles, we made partially pre-gelatinized wheat flour dough by the microwave heating method. A cylindrical-shaped piece of wheat flour dough containing 3% NaCl was heated by 117 W microwave oven operating at 2450 MHz. The sample dough was intermittently heated to allow sufficient gelatinization of the starch granules of the dough. The resultant changes in the internal temperature profiles of the sample dough were measured and compared with numerical prediction, which is the two-dimensional heat conductive equation with a term for internal heat generation based on Lambert’s law. In order to calculate the internal heat generation during microwave heating, we measured the dielectric properties of wheat flour dough at 2450 MHz from 10 to 70 °C by the open-ended coaxial probe method. The calculated temperature history could describe the feature of the experimental one during intermittently microwave heating. Furthermore, the progress of starch gelatinization according to the heat transfer in the sample dough was predicted by the Runge–Kutta gel method. A tendency that the total gelatinization degree increased slowly during the microwave intermittent heating was obtained in the calculated result.     

Gelatinization properties of wheat flour as determined by empirical and fundamental rheometric method

Certain empirical rheological methods are in extensive use in wheat and/or flour research to assess starch gelatinization and pasting behavior primarily due to easy performance and good correlation with final product quality. However, their applications are often associated with specific drawbacks that could be limiting factors for certain applications, such as poor definition of the measured parameters, time-consuming nature, difficulties in interpretation of results, large sample sizes, etc. The listed shortcomings can be overcome by application of fundamental rheological methods that are based on well-defined rheological parameters such as stress, strain, viscosity and modulus. The objective of this study was to optimize the fundamental rheological method for determination of the gelatinization properties of wheat flour that correspondents to the standard widely accepted empirical rheological method—Amylograph method and to compare them in order to determine whether they can be interchangeable depending on different analytical needs. The obtained results have shown that the application of fundamental rheometric procedure for determination of pasting properties of wheat flour provides reliable determination of the gelatinization properties of wheat flour. Moreover, substantial advantages of fundamental rheometric method over the empirical one were identified including smaller sample size, ability to set the desirable heating and shear rate, shorter test duration and better precision.     

蛀蚀害虫侵害后小麦粗淀粉含量及其糊化特性变化

为探讨蛀食性害虫玉米象、米象侵害后小麦粗淀粉含量和全麦粉糊化特性的变化,选用河南产储藏3年的商品小麦为材料,按不同虫种分组,设定不同的虫口密度和侵害时间,检测害虫感染后小麦粗淀粉含量和全麦粉的糊化特性。结果表明:玉米象和米象不同程度感染后小麦粗淀粉含量总体呈下降趋势;无论是同一虫口密度随着蛀蚀时间的延长,还是同一蛀蚀时间下随虫口密度增加,其感染后的全麦粉峰值黏度、最低黏度、最终黏度、衰减值和回生值均呈下降趋势;糊化温度呈上升趋势,峰值时间基本无变化;粗淀粉含量与峰值黏度、最低黏度、最终黏度、衰减值和回生值均存在极显著正相关,与糊化温度呈极显著负相关,与峰值时间无相关性。     

Effect of Chlorine Treatment on Wheat Flour and Starch: Measurement of Thermal Properties by Differential Scanning Calorimetry

Differential scanning calorimetry (DSC) was used to study the effect of chlorine treatment of wheat flour on the heat of gelatinization of the wheat flour and starch. The DSC thermograms were corrected for heat capacity changes and thermal lag. An endothermic transition occurred in both flours and starches at a temperature commonly associated with starch gelatinization. The enthalpy (ΔH) for the starches was concentration dependent. The chlorine treatment did not affect significantly the transition temperatures nor enthalpies of either the flour or the starch isolated from it. Addition of sucrose delayed the onset of gelatinization and increased the ΔH for both treated and untreated wheat flours and starches.     

抗性淀粉对面粉品质及面团流变学特性影响研究

探讨抗性淀粉对小麦粉流变学特性的影响。分别考察了其对高筋粉、中筋粉的粉质特性、拉伸特性和糊化粘度特性的影响,结果表明,抗性淀粉的添加在一定程度上影响了小麦粉的流变学指标和面粉品质。具体表现为面团稳定时间和粉质评价值降低,弱化度增加,延伸度与拉伸曲线面积降低。抗性淀粉的添加使高筋粉的糊化温程升高,糊化时间延长,对中筋粉的糊化温程和时间影响较小。     

Whey protein concentrate gels with honey and wheat flour

Structural and functional properties of whey protein concentrate (WPC) gels with different honey and wheat flour contents, prepared at pHs 3.75, 4.2 and 7.0, were analysed. Gel structure was observed by scanning electron microscopy. The apparent transition temperatures for protein denaturation and starch gelatinization were determined by differential scanning calorimetry. Gels were characterised through solubility assays in different extraction solutions and polyacrylamide gel electrophoresis of the soluble protein components. The firmness, elasticity, relaxation time, adhesivity and cohesiveness of gels were determined, and the water-holding capacity and superficial colour of gels were also studied. Results suggest that wheat flour could interact with whey proteins, and produces a decrease in the protein solubility of WPC gels, and in the temperature of whey protein denaturation. The effect of wheat flour on the functional properties of WPC gels was different at acidic than at neutral pH: the presence of wheat flour produced an increase in the relaxation time and in the cohesiveness of gels prepared at pH 3.75, whereas at neutral pH a decrease in both properties was observed. Honey and flour content increased the water-holding capacity and browning of WPC gels.     

添加辣木叶粉对小麦粉面团品质的影响

考察不同粒径辣木叶粉对小麦面团品质的影响。采用普通粉碎、超微粉碎技术制备不同粒径的辣木叶粉,采用分光测色计、粉质仪、拉伸仪、黏度仪分析辣木叶粉对小麦面团品质的影响。结果显示添加5%辣木叶粉后,小麦粉的吸水率、糊化温度没有显著变化;形成时间、稳定时间均显著下降;45 min醒发后的最大拉伸阻力由234.9 BU下降至130 BU左右,延伸度下降;峰值黏度由531 BU显著下降至303～355 BU,回生值亦下降,衰减值上升。结果表明添加辣木叶粉一定程度减弱了小麦面团的面筋强度和淀粉黏性,但减弱了小麦粉面团的回生,超微粉碎可以减弱辣木叶粉对小麦粉面团的负面影响,研究为辣木叶粉在面制品行业的应用提供了理论参考。     

山药薏米芡实混合粉对小麦粉加工品质的影响

在小麦粉中加入山药、薏米、芡实混合粉,利用快速黏度分析仪、Mixolab混合实验仪和质构仪分析不同添加量的混合粉对小麦粉糊化特性、面团热机械学特性以及对馒头质构特性的影响.结果表明:随着混合粉添加量的增加,小麦粉的糊化黏度、崩解值、回生值、糊化温度、糊化时间、面团吸水率、形成时间和稳定时间逐渐降低,蒸煮稳定性和蛋白质弱...     

Evaluating quality of yellow alkaline noodles made from mechanically abraded sprouted wheat

Five hard red spring wheat genotypes, with initial falling numbers (FNs) ranging from 62 to 427 s, were mechanically abraded for 30, 60, and 120 s to reduce sequentially α‐amylase activity in the grain. Mechanical abrasion prior to milling significantly increased FN and reduced amylase activity in pre‐harvest sprouted wheat. The abraded grains were milled and the resultant flour samples were evaluated for starch gelatinization properties and yellow alkaline noodle (YAN) quality. Mechanical abrasion on sprouted kernels resulted in significant improvements in starch pasting properties accompanied by marginal decreases in flour ash and protein contents. Initial noodle brightness L* improved in most samples with mechanical abrasion. However, L* values dropped significantly during storage, with the greatest decline seen in the highly sprouted sample. Noodle cooking and textural qualities were relatively unaffected by sprout damage or mechanical abrasion, possibly due to amylase inhibition by the carbonate salts present in the formula. Mechanical abrasion prior to milling was found to reduce amylase activity significantly in moderately sprouted wheat. YAN, however, showed high tolerance to sprout damage, and produced noodles of acceptable texture without mechanical abrasion. Copyright © 2003 Society of Chemical Industry