大豆面团粘度模型的试验拟合

粘度 η是影响螺杆食品挤压蒸煮机内面团流动过程模拟、运行能耗预测、结构优化设 γ计的重要参数。本文经过试验测定和参数拟合 ,得到了如下一个随温度t、剪切速 γ和湿含量M变化的粘度模型 :η =80 719 γ -0 83 8·exp( 3 5 16 667t 2 73 )·exp( -6 3 83M )     

小麦胚芽对面团特性影响机理探讨

小麦胚芽是小麦籽粒富集营养成分部位,在小麦制粉时会有或多或少小麦胚芽混入面粉。通过全脂和脱脂小麦胚芽对面团影响研究,测定小麦胚芽不同添加量对面团流变学特性及发酵前后面团中巯基/二硫键含量变化,初步探讨小麦胚芽对面团特性影响机理。结果表明,小麦胚芽添加量不大于3%时,面团分析结果较优,流变学特性有所提高,面筋结构得以强化;当小麦胚芽添加量大于3%时,各项指标逐渐下降、品质劣化,且添加全脂和脱脂小麦胚芽对面团影响趋势基本一致;但脱脂小麦胚芽影响相对缓和,且少量(2%³%)添加时以全脂小麦胚芽影响效果更好。     

影响面团褐变因素的研究

通过硫酸铵盐析、透析袋透析脱盐、Sephadex G-200柱层析的方法,从小麦全麦粉中分离纯化了多酚氧化酶。该酶为对热不稳定的酶,其最适反应湿度为50－60℃,最适反应pH为5．6－6．0。在以邻苯二酚为底物时,km为8．4mmol/l。小麦面粉出粉率越高、面团含水量越大、储藏温度越高,面团褐变速度越快,且褐色程度随时间的延长而加深。     

紫薯粉对小麦面团加工特性影响的研究进展

综述了近年来对紫薯—小麦混合粉加工特性的研究,总结了紫薯粉对小麦面团在粉质、质构、拉伸、动态流变等流变特性影响的变化规律,重点对糊化、老化两个热力学特性影响的变化规律进行总结,在此基础上,分析了当前紫薯—小麦混合粉研究中存在的问题,并对其未来的研究方向进行了展望。     

小麦面团黏度的影响因素研究

以河南省农科院的26个小麦品种为材料，进行面团黏度性状和面粉的几个理化指标之间相关性的研究，包括蛋白质含量、干面筋、湿面筋、面筋指数、降落数值、淀粉含量、直链淀粉含量、支链淀粉含量及直／支淀粉含量的比例。结果表明：面团的黏度性状与蛋白质含量、面筋指数、降落值、直链淀粉的含量，以及直／支淀粉含量的比例之间具有显著的负相关性，与支链淀粉含量具有显著的正相关性。     

优质小麦蛋白质组分和面团流变学特征

<正> 小麦是我国主要粮食之一,总产量居于世界第四位。全国分为六个产麦区,其中90％以上为冬小麦,主要分布在华北平原、黄淮平原和淮南冬麦区。中国农科院作物育种栽培研究室在七五期间,测定全国各省市广泛推广的良种品质的结果,指出国内现在种植的冬小麦品种,     

小麦面团黏度的影响因素研究

以河南省农科院的26个小麦品种为材料,进行面团黏度性状和面粉的几个理化指标之间相关性的研究,包括蛋白质含量、干面筋、湿面筋、面筋指数、降落数值、淀粉含量、直链淀粉含量、支链淀粉含量及直/支淀粉含量的比例。结果表明:面团的黏度性状与蛋白质含量、面筋指数、降落值、直链淀粉的含量,以及直/支淀粉含量的比例之间具有显著的负相关性,与支链淀粉含量具有显著的正相关性。     

冷冻面团中影响面团筋力因素

面团筋力影响冷冻面团稳定性,而面团筋力又受到面团加水量,面粉种类,添加剂等影响。可通过选择面粉种类,改变加水量,添加添加剂等手段提高冻冷面团稳定性。     

Secalin蛋白检测及其与面团黏性关系的研究

用SDS—PAGE检测了70个小麦品种是否带有黑麦Secalin蛋白，并测试了它们的面团黏性，用PCR检测了部分品种是否含有1RS染色体片断，结果表明：70％的品种为1B／1R易位系；有54．3％的品种面团发黏；带有黑麦Secalin蛋白的品种约有72．5％面团发黏，而不带有黑麦Secalin蛋白的品种只有30％面团发黏；影响面团黏性的主要因素为来源于黑麦的Secalin蛋白；PCR扩增结果表明，在我国存在不带有Sec-1基因的1B／1R小片断易位系。     

Origin and practical significance of the sticky dough factor in 1BL/1RS wheats

When translocated into wheat, the short arm of the 1R chromosome of rye carries with it linked resistance genes to powdery mildew, stripe rust, leaf rust and stem rust. The translocation is also reported to increase yield potential of hard wheats. However, many doughs made from some 1BL/1RS hard wheats are unacceptable for breadmaking purposes because of excessive stickiness and mixing intolerance. 1BL/1RS wheats may be sticky because of: the inheritance of secalin proteins from rye and absence of key glutenin subunits; higher amounts and/or differences in the composition of cell wall polysaccharides, β‐glucans and pentosans; and/or the presence of a ferulic acid ester moiety residing with the water‐soluble fraction of 1BL/1RS flours. None of these hypotheses has been proven or disproven, to date, as a cause of excessive stickiness. Investigators have found that 1BL/1RS doughs are not uniformly sticky and are in some instances less sticky than non‐1BL/1RS doughs. Significant genotype–environment interactions have been reported for dough stickiness and flour quality characteristics of 1BL/1RS wheats. Investigators have generally failed to find significant differences in the breadmaking performance of 1BL/1RS and non‐1BL/1RS hard wheats despite a report that 1BL/1RS doughs break down and soften during high‐speed mixing. The 1BL/1RS translocation has been shown to reduce cookie spread of soft wheat flours but has no deleterious effects on cake volume or texture. © 2002 Society of Chemical Industry     

Effects of Waxy Wheat Flour and Water on Frozen Dough and Bread Properties

ABSTRACT:  The quality of bread made from frozen dough is diminished by changes that occur during freezing. New cultivars of waxy wheat flour (WWF), containing less than 2% amylose, offer unique properties for the production of baked products. In this study, dough properties and bread quality were investigated at various levels of WWF (0% to 45% flour weight) and water (55% to 65%). Dough stickiness increased with higher levels of WWF and water. During frozen storage, dough with greater WWF and lower water had less change in stickiness. Maximum resistance to extension (MRE) decreased with higher WWF and water. Dough with greater WWF and less water had less change in extensibility after frozen storage. Dough with greater WWF and water was more extensible. Nuclear magnetic resonance (NMR) studies showed that frozen dough with higher WWF content had lower transverse relaxation ( T ₂) time of 9 to 11ms. After frozen storage, dough with higher WWF still showed lower T ₂. Dough with 15% WWF had higher yeast activity. Bread made from 15% and 30% WWF had higher volume in bread made from unfrozen and frozen dough. Bread firmness decreased with higher amounts of WWF and water. This research demonstrated that specific combinations of WWF and water produced a better quality of frozen dough and bread.     

全麦冷冻面团研究进展

冷冻面团是全麦食品的一种良好载体,可简化生产操作,降低加工难度,加快全麦食品的工业化生产。综述了全麦食品中的膳食纤维对面团及冷冻面团品质的影响,在冷冻和冷藏过程中全麦冷冻面团的发酵特性和流变学特性的变化,以及食品改良剂对全麦冷冻面团的品质改善等研究。通过分析全麦冷冻面团中面筋蛋白、淀粉、发酵特性、流变学特性等在冷冻和冷藏过程中劣变原因,为改善全麦冷冻面团的品质提供理论基础和实践参考。     

Physicochemical Properties of Wheat Flour Dough Modified by Microbial Transglutaminase

ABSTRACT: In this study, microbial transglutaminase (MTGase) was employed to modify viscoelasticity of wheat flour dough. Three flours, namely In-, Mid-, and Out-flour derived from different parts of wheat kernel, were used. When adding 16 ppm MTGase, the maximum resistance to extension (R_max) of In-(58%), Mid-(56%), and Out-flour(52%) doughs, prepared at specific water levels indicated in parentheses, is increased by 51%, 35%, and 77%, respectively. The extensibility (E) of these 3 doughs is reduced by 16%, 11%, and 6%; the stickiness is also lowered by 12%, 5%, and 22%, respectively. SDS-PAGE analysis indicates that crosslinks occur within wheat gluten of MTGase-treated dough.     

关于面团稠度特性的小麦高分子量麦谷蛋白亚基评分系统研究

针对现有高分子量麦谷蛋白亚基(HMW-GS)评分系统的局限性,选用100个春小麦品种,测定了其HMW-GS以及面团最大压力、形成时间和稳定时间等3项面团稠度特性,并通过数量化理论及统计学鉴评方法,研究了HMW-GS与面团稠度特性的关系,得到了3个多元回归方程,决定系数均在0.98以上,能准确预测3个面团稠度特性,建立了针对不同面团稠度特性的HMW-GS评分系统。总体来看,7亚基、5 10亚基和10亚基对面团稠度特性有积极意义,属于优质亚基。7亚基对所有面团稠度特性的亚基评分最高,5 10亚基对面团最大压力的评分较高,10亚基对面团形成时间和稳定时间的评分较高。而2 10亚基、2 12亚基、22亚基和17 18亚基对面团稠度特性的评分最小,其中,17 18亚基对所有面团稠度特性的亚基评分最低,2 10亚基、2 12亚基和22亚基对所有面团稠度特性的亚基评分也较低,为劣质亚基。     

D-Erythroascorbic Acid in Bakers'Yeast and Effects on Wheat Dough

Extraction of hydrated and freeze-dried bakers’yeast yielded ～ 50 μg erythroascorbic acid (EAA) and 5 μg ascorbic acid (AA)/g dry yeast as determined by HPLC with electrochemical detection. D-EAA (82 ppm based on flour) slightly increased the flow of dough as rest time increased. Gluten isolated from a flour-water dough containing 82 ppm D-EAA or 100 ppm Lcysteine stretched at a faster rate than control gluten. EAA like AA did not change dough development time. Unlike AA, EAA showed neither oxidizing effect on dough and gluten nor improving effects on bread.     

Effect of Wheat Bran Particle Size on Dough Rheological Properties

Commercial hard red spring, hard red winter, soft white and durum wheat brans were used to investigate the effect of wheat bran particle size on the rheological properties of doughs. Wheat brans were first coarsely ground and passed through a bran finisher to remove additional endosperm and aleurone layers. These processes increased total dietary fibre content and decreased starch content of the wheat bran samples. Three particle size distributions, for each wheat bran class, were obtained by further grinding (not by sifting) of the bran samples by different experimental mills. Coarse bran can retain significantly more water than medium or fine bran as measured by a centrifuge method, but bran particle size had no significant effect on dough water absorption. Addition of wheat bran into bread dough systems increased dough water absorption rate, reduced mixing time and decreased dough mixing tolerance as measured by farinograph. Fine particle size wheat bran decreased dough mixing tolerance and reduced mixing time compared to coarse bran. Dough containing fine particle size bran exhibited more strength than dough containing coarse bran after a 180-min rest period as measured by the extensigraph. © 1997 SCI.     

影响冷冻面团的因素及其品质改良研究进展

冷冻面团技术因具有延长货架期、防止老化、便于冷藏和运输等优越性,在国内外食品工业得到了广泛的应用。然而,冷冻面团的生产和储存也会面临诸多困难,例如酵母活性降低、面筋结构破坏和冰晶形成等,这些都会破坏冷冻面团的质量。本文概括总结了影响冷冻面团品质因素的作用机理及研究现状,并总结了提高酵母耐冻性、改善面筋结构和面团特性的有效方法。添加改良剂可以减小由于冻藏或冻融循环致使面筋网络破坏的程度,添加谷氨酰胺转氨酶可改善冷冻面团的粘弹性与面筋网络结构,还可明显增加冷冻面团面包的比容,减小面包芯的硬度。选用优质酵母可提高酵母在冷冻期间的发酵力,改善冷冻面制品的风味和口感,其中高产胞外多糖的乳酸菌可以有效改善冷冻馒头面团品质。冷冻面团技术推动了我国馒头、包子、饺子、月饼等中式面食制品快速发展,具有一定的发展潜力。