红枣粉添加量对面团特性及馒头品质的影响

研究红枣粉对面团特性及馒头品质的影响,确定适宜的红枣粉小麦粉配比。探讨了添加不同比例红枣粉（0、5%、10%、15%）对混合粉理化性质、色差、面团的微观结构和粉质拉伸特性,以及对馒头比容、色差、质构和感官品质等的影响。结果表明:随着红枣粉添加量的增加,混合粉中的水分、蛋白质和脂肪含量逐渐降低,灰分和还原糖的含量逐渐升高;混合粉及馒头的颜色逐渐变红变暗;面团吸水率逐渐降低,形成时间与稳定时间呈先上升后下降,弱化度呈先下降后上升的趋势;添加不同比例红枣粉面团随着醒发时间（45、90、135 min）的延长,面团拉伸能量、最大拉伸阻力和拉伸比等指标总体呈上升趋势;面团微观结构显示随红枣粉添加量的增加,面筋蛋白结构逐渐遭到破坏;红枣粉添加量在5%~10%范围内,馒头比容与对照组馒头相比显著增大（P<0.05）;馒头的弹性、回复性随红枣粉的添加逐渐降低;感官评定显示红枣粉添加量在5%~10%范围内,总体得分均比对照组馒头要高,且易被人们接受。综合分析红枣粉对面团特性、馒头质构及感官评价等的影响结果,确定红枣粉添加量不宜超过10%。     

米酒老面添加量对面团及馒头品质的影响

本文研究了米酒老面添加量(40%、50%、60%、70%和80%)对面团的pH、湿面筋含量、面筋指数及馒头的比容、硬度、白度、感官评分的影响。结果表明:随着米酒老面添加量的增加,面团pH呈现下降的趋势。米酒老面添加量为60%的面团中湿面筋含量显著低于其他四种添加量(P<0.05),馒头的比容、硬度、白度和感官评分显著高于其他四种添加量(P<0.05)。相关性分析表明,面团pH与馒头的感官评分呈极显著负相关(P<0.01);面团湿面筋含量与馒头比容呈显著负相关(P<0.05),与馒头硬度呈显著正相关(P<0.05),与馒头白度呈极显著负相关(P<0.01)。面团面筋指数与馒头比容呈极显著正相关(P<0.01),与馒头硬度呈极显著负相关(P<0.01),与馒头白度呈显著正相关(P<0.05)。米酒老面的添加会改变面团和馒头的品质,其最适添加量为60%。     

不同溶解特性的醇溶蛋白亚组分对馒头面团特性的影响

为探究醇溶蛋白对馒头面团特性的影响,在特一粉中分别加入提取出的醇溶蛋白亚组分(gli8、gli9、gli10、gli11、gli15),分析五种亚组分对馒头面团面筋指数、湿面筋含量、拉伸特性、游离巯基含量、醒发过程中对馒头坯的高和径变化的影响。结果表明,添加gli8的未醒发馒头面团的拉伸断裂力为127.92 g,是对照组的1.52倍;拉伸距离也与对照组相差最大,是对照组的76.89%。添加gli9对面团特性相比于其他亚组分没有显著性影响(p>0.05)。添加gli10对面团的游离巯基含量影响最大,为2.48 μmol/g,是对照组的1.17倍。添加gli11的馒头面团的面筋指数相比于对照组有显著性减小(p<0.05),为10.15%,是对照组的52.12%,但湿面筋含量高于对照组。添加gli15也使面团的面筋指数显著性减小(p<0.05),使醒发后的馒头面团拉伸距离显著性增大(p<0.05)。在醒发过程中,添加gli8和gli15使馒头坯径度变化受到了一定的抑制;添加gli9、gli10和gli11使馒头坯的高度变化受到一定的抑制。由此得出,不同的醇溶蛋白亚组分对面团特性的影响有着明显的不同。     

Yeast leavened banana-bread: Formulation,processing, colour and texture analysis

Banana powder (BP) was added to hard-red spring wheat (HRSW) flour intended for yeast-leavened bread formulation. Five different formulations containing 10%, 15%, 20%, 25%, and 30% BP were prepared with varying amounts of base flour, while vital gluten was maintained at 25% in all blends. Based on the added BP amounts only, the prepared bread could deliver 42.87–128.6 mg potassium/30 g of bread (one regular slice) and 0.33–1.00 g of fibre. Although the dough water absorption was increased, due to BP addition, the dough mixing tolerance (MTI) decreased. The bread loaf volume was significantly higher than the control except for the 30% blend, where the loaf volume was similar to the control. Bread staling increased with BP levels due to the high sugar content but, this effect was limited to the first two days of storage. Blends exhibited darker colour due to the high sugar and protein, while the 25% and 30% blends had the lowest percent of freezable water. The amounts of acetic acid extractable proteins from the dry blends and the dough decreased with increase in BP. The linear rheological properties of the control, 10%, and 30% blends exhibited similar viscoelastic solid behaviour, where both G′ and G′′ had plateaus (G′ > G′′) and they were parallel to each other over three decades of the frequency. Blends showed higher moduli values than the control.     

X-ray micro-computed tomography evaluation of bubble structure of freeze-dried dough and foam properties of bread produced from roasted wheat flour

This study evaluated the bubble structure of freeze-dried dough and foam properties of bread produced from the roasted wheat flour by means of X-ray micro-computed tomography (μCT). Wheat was roasted at 90 °C and 86 Hz, of which the conditions was determined by means of a central composite design, and the flour used to produce dough proofed for 20- and 40 min as well as bread. The use of 10 g dough and bread samples enabled scanning at a much higher resolution. Roasting resulted in a decreased strut thickness of the bread, suggesting a finer crumb structure and softer texture, compared to the control. Porosity increases were observed for the roasted wheat samples. This suggested a slightly weaker gluten strength as was observed with the lower mixograph peak height. Roasting wheat, at the conditions determined by the central composite design, did not negatively affect the foam properties of the breads produced from the roasted wheat flour.     

Bran-induced changes in water structure and gluten conformation in model gluten dough studied by Fourier transform infrared spectroscopy

The impact of bran addition on the state of water and gluten secondary structure in gluten dough was studied using Fourier transform infrared spectroscopy to understand the underlying physical mechanism by which bran impacts dough properties. Comparison of the OH stretch band of water in gluten dough with that of H₂O–D₂O mixture having the same water content revealed formation of two distinct water populations in gluten dough corresponding to IR absorption frequencies at 3580 cm⁻¹ and 3180 cm⁻¹. The band intensity at 3180 cm⁻¹, which is related to water bound to gluten matrix, decreased with increase of moisture content of the dough. Addition of bran to gluten dough caused redistribution of the bound water in the gluten-bran dough system. This water redistribution affected the secondary structure of gluten in the dough as evidenced from changes in the second-derivative spectrum in the amide I region. In the hydrated state, β-turn (in the form of β-spiral) was the major secondary structure (∼60%) in gluten. Addition of bran to gluten dough caused conversion of β-spirals into β-sheet and random structures. However, the extent of this conversion in the presence of bran was inversely related to the moisture content of the dough. This study revealed that when bran is added to gluten dough, water redistribution promotes partial dehydration of gluten and collapse of β-spirals into intermolecular β-sheet structures; this trans-conformation might be physical reasons for the poor quality of bread containing added bran.     

发芽糙米粉面团性质及面包品质研究

将未发芽和发芽12、24、36、48 h的糙米磨粉,分别与20%的谷朊粉混合制作面团和面包,研究了发芽糙米-谷朊粉面团流变性质及面包品质。结果表明,随着发芽时间的增加,糙米面团弹性模量和粘性模量均降低。扫描电镜结果显示,发芽12 h和24 h糙米面团形成均匀致密的网络结构,发芽24 h后,网络结构部分破裂。随着发芽时间的延长,糙米面包比容、弹性、回复性降低,硬度先降低后升高。发芽12 h和24 h,糙米面包硬度较低,比容、弹性和回复性较大。发芽12 h的糙米面包感官评分最高。因此,发芽12 h时的糙米面包品质最好。     

Effect of baked wheat germ on gluten protein network in steamed bread dough

The effect of baked wheat germ (BWG) on the gluten network structure in steam bread dough was investigated. The secondary structure, free sulphydryl (-SH) content, disulphide (-SS-) bonds content and microstructure of gluten were analysed to evaluate gluten structural changes. The addition of different amounts of BWG (0, 2, 4, 6, 8, 10, and 12%) in dough resulted in decreased content of α-helix and β-sheet structures, but increased random coils, which indicated that a disordered structure was formed. The presence of BWG increased the -SH content but decreased the -SS- bonds content, which indicated fracture of disulfide bonds. Confocal laser scanning microscopy (CLSM) analysis indicated that steamed bread dough containing BWG had larger-sized gas cell and granules of starch separated by the protein matrix, which weakened the gluten network structure. These changes may inevitably affect the viscoelastic properties of steamed bread dough.     

Hard Red Spring wheat/C-TRIM 20 bread: Formulation,processing and texture analysis

C-TRIM, a β-glucan-rich fraction, was added to Hard Red Spring wheat (HRSW) flour to increase soluble fiber content of bread, and to obtain a minimum of 0.75 g/bread serving (0.75 g/30 g or 2.5%) required by FDA for health claim. Three treatments or blends FGT0 (100% wheat flour – control), FGT1 (58% flour, 25% gluten and 17% C-TRIM) and FGT2 (60% flour, 22.5% gluten, and 17% C-TRIM) were used in the study. The total amount of soluble fiber from C-TRIM in FGT1 and FGT2 was 4.07–4.17% which was more than the amount required by FDA. The presence of C-TRIM increased both, the Farinograph water absorption and the arrival time. The dough mixing tolerance index (MTI) was also increased by C-TRIM. The FGT1 had higher stability than FGT2, whereas, the loaf volume of FGT1-B was also significantly higher than FGT0-B control and FGT2-B bread. The DSC results indicated that the amount of freezable-water in C-TRIM treated bread (FGT1-B and FGT2-B) was significantly higher than the control wheat flour bread (FGT0-B). This may be attributed to the higher amount of water absorbed by C-TRIM during bread dough (FGT1-D and FGT2-D) preparation and trapped or bound within the bread matrix after baking as compared to the control. After storage of FGT0-B, FGT1-B, and FGT2-B breads 2, 5, and 7 days storage at 25 °C, 4 °C, and −20 °C, the texture of bread were measured with a Texture Analyzer and the data analyzed statistically. The FTG0-B control bread firmness was significantly higher than FGT1-B and FGT2-B C-TRIM treated breads after 7 days storage at 25 °C. The amount of 0.1 M acetic acid-extractable protein was lower in FGT1-B than the control wheat flour (FGT0-B) sample. In addition, more protein was extracted at pH 7.0 than pH 4.5 because of less charges at neutral pH than pH 4.5. The free zone capillary electrophoresis analysis showed obvious differences in the protein charge and size between the dough and bread.     

The influence of 1B/1R chromosome translocation on gluten protein composition and technological properties of bread wheat

The Austrian bread wheat Amadeus without and with 1BL/1RS translocation and three further translocation genotypes with known HMW subunit compositions were grown under the same environmental conditions. Their flours were characterised by the determination of crude protein content and, partly, by the determination of glutathione and cysteine. Furthermore, the qualitative and quantitative composition of gluten protein types was analysed by a combined extraction and reversed phase HPLC procedure. Dough development time, maximum resistance and extensibility of dough and gluten, and bread volume were determined by means of microscale methods. Protein, glutathione and cysteine contents of flours were only slightly influenced by translocation. The HPLC patterns of gliadins and glutenin subunits showed that translocation caused characteristic changes concerning ω‐gliadins, γ‐gliadins and LMW subunits of glutenin. The amount of ω 1,2‐gliadins was significantly increased and that of LMW subunits decreased. The effect of translocation on the rheological properties of dough and gluten was characterised by a strongly reduced dough development time, reduced maximum resistance and increased extensibility. Bread volume was decreased by about 10%. The amount of glutenin subunits was correlated with dough development time, resistance of dough and gluten, and bread volume to a higher extent (r = 0.79–0.91) than the amount of gliadins (r = 0.52–0.80). Correlation coefficients for LMW subunits were higher (r = 0.82–0.88) than those for HMW subunits (r = 0.35–0.61) when all five wheats were included. Instead, when only translocation lines were considered, HMW subunits (r = 0.89–0.98) were more important than LMW subunits (r = 0.64–0.86). Altogether, the results demonstrate that translocation causes important quantitative as well as qualitative changes in gluten protein composition which can be efficiently determined by reversed phase HPLC. © 2000 Society of Chemical Industry     

木糖醇对面团特性及面包品质影响的研究

本试验就木糖醇对面团特性及面包品质影响进行了研究.结果表明,木糖醇可降低面团的吸水率,延长面团的形成时间、稳定时间;适量添加可增加面团的拉伸能量、延伸度和拉伸阻力;添加木糖醇可显著减少小麦粉的峰值黏度、最低黏度、衰减值、最终黏度、回生值和峰值时间,有效降低淀粉老化速度;添加适量木糖醇可有效保持面包体积,降低面包的硬度,增加面包的含水量,改善面包的焙烤特性,延长其货架期.综合分析,在本试验条件下,木糖醇的添加量不宜超过16％.     

双乙酰酒石酸单双甘油酯对全麦面团特性及全麦馒头品质影响

为了改善全麦中麸皮带来的不利影响,本文尝试向全麦粉中添加双乙酰酒石酸单双甘油酯(DATEM,0~1.0%)改变全麦面团特性同时改善全麦食品品质。利用混合实验仪(Mixolab)、质构仪、动态流变仪、扫描电镜、激光共聚焦等研究了DATEM对全麦面团的混合特性、流变特性、拉伸特性和微观结构及其对全麦馒头比容、质构特性的影响。结果发现,DATEM使得全麦面团形成时间、稳定时间与回生值均升高,峰值粘度降低。DATEM添加增加了面团拉伸强度,弹性模量(G")和黏性模量(G"),但降低了面团延伸性。全麦面团微观结构显示,添加DATEM后面团内部断裂减少,结构均匀连续,面筋结构得到明显改善。DATEM使得全麦馒头硬度显著降低(p<0.05),由1546.70 g(对照)降低到680.56 g(DATEM 1.0%),当添加量为0.4%时,全麦馒头的比容比对照增加了1.2倍。     

碱添加量对米酒酸面团及馒头品质的影响

该实验研究了碱添加量对面团的pH、湿面筋含量、面筋指数及馒头的比容、硬度、白度、感官评分的影响。结果表明,碱添加量与pH值呈线性关系。碱添加量为0.20%时,显著降低了面团中湿面筋含量,但提高了面筋指数。碱添加量＞0.20%之后,馒头的感官评分、白度、比容呈现降低趋势,硬度呈现上升趋势。相关性分析结果表明,面团pH值与馒头的比容、白度呈极显著负相关（P＜0.01）;与馒头的感官评分呈极显著正相关（P＜0.01）。面团湿面筋含量与馒头比容呈显著负相关（P＜0.05）,与馒头硬度呈极显著正相关（P＜0.01）。面团面筋指数与面团比容呈显著正相关（P＜0.05）,与馒头硬度呈极显著负相关（P＜0.01）。     

Effects of trypsin‐hydrolyzed wheat gluten peptide on wheat flour dough

BACKGROUND: Gluten peptide was prepared by trypsin hydrolysis and characterized by high‐performance liquid chromatographic analysis. The effects on non‐frozen and frozen doughs of trypsin‐hydrolyzed gluten peptide (THGP) and its combination with ascorbic acid or KBrO₃ were investigated. RESULTS: Molecular analysis of THGP showed a decrease in the high‐molecular‐weight and an increase in the low‐molecular‐weight sodium dodecyl sulfate‐soluble fractions, compared with those of control wheat gluten. The addition of 8% THGP decreased the mixing time and tolerance of the dough, both with and without ascorbic acid or KBrO₃. However, the maximum resistance and extensibility of the rested dough containing 8% THGP, with and without ascorbic acid or KBrO₃, were not significantly different from those of the control dough. The addition of 8% THGP significantly increased the loaf volume of bread baked from non‐frozen dough when combined with 60 ppm ascorbic acid or 30 ppm KBrO₃, but it had a significant effect both with and without ascorbic acid or KBrO₃ on frozen‐dough bread. A large difference in volume was observed between breads made with and without THGP at the oven‐spring, rather than at proofing. CONCLUSION: The addition of 8% THGP increased the loaf volume of bread made from freeze‐damaged dough and this effect increased when THGP was combined with 60 ppm ascorbic acid. Copyright © 2008 Society of Chemical Industry     

冻藏时间对冷冻面团馒头品质的影响

为探究冻藏时间对冷冻面团馒头品质的影响,本文通过采用酵母菌活性测定、馒头质构特性测定、面筋蛋白二级结构测定、扫描电镜观察等方法,从宏观和微观的角度上分析了冻藏时间的延长对冷冻面团馒头品质的影响。结果表明,随着冻藏时间的延长,酵母菌数量及存活率均呈下降趋势,其中冻藏1周后,表面和内芯的酵母菌数量均减少5.8 lg CFU/g;经过5周冻藏后,冷冻面团馒头的硬度、咀嚼性、胶着性分别增大74.6%、75.7%、75.6%;面筋蛋白二级结构中α-螺旋也随着冻藏时间的延长呈下降趋势,蛋白二级结构稳定性逐渐下降;经过扫描电镜观察发现,面筋网络结构逐步减少,淀粉颗粒与面筋结构分离,部分淀粉颗粒完全裸露。因此表明冻藏时间的延长,会导致冷冻面团馒头品质下降。本研究结果为后续提高冷冻面团馒头品质应用研究提供理论依据。     

Transglutaminase and tyrosinase as potential cross-linking tools for the improvement of rheological properties of gluten-free amadumbe dough

Gluten-free bread remains of poor quality despite efforts to amend gluten-free flours with ingredients such as hydrocolloids and proteins. Enzymatic modification of the proteins in dough may result in polymers that mimic gluten. This research investigated the effects of transglutaminase and tyrosinase on the rheological properties of amadumbe dough. Tyrosinase oxidation resulted in a 7.7–39.4% decrease in dough-free amine, and a 16.8–46.3% decrease in the dough thiol content as activity was increased from 0 to 80 U g⁻¹ flour. Transglutaminase treatment decreased the dough-free amino groups by 10–38.1% as activity was increased from 0 to 2 U g⁻¹ flour. Evidence of tyrosinase and transglutaminase-mediated cross-linking was provided by relevant model reactions monitored by mass spectrometry. An increase in dough G′ and G″ showed that both transglutaminase and tyrosinase improved dough viscoelasticity. The increase in the viscoelasticity of the dough potentially improves carbon dioxide retention during proofing.     

品质改良剂对复合杂粮面包粉流变学特性的影响

以营养优化后的复配杂粮面包粉为原料,选择谷朊粉、硬脂酰乳酸钠（sodium stearoyl lactylate,SSL）、黄原胶及瓜尔豆胶为品质改良剂,通过单因素试验研究4 种品质改良剂对杂粮面包粉流变学特性的影响,在此基础上通过响应面分析试验,以面团综合得分为响应值,得出复合改良剂的最佳配方为：1 000 g杂粮面包粉（杂粮粉占比34%）为基重,谷朊粉3.77%、SSL 0.35%、黄原胶1.08%、瓜尔豆胶0.35%。各因素对杂粮面包粉综合评分的影响大小为：黄原胶添加量＞谷朊粉添加量＞瓜尔豆胶添加量＞SSL添加量。添加复合改良剂后杂粮面包粉的稳定时间由4.7 min上升到14.2 min,形成时间由3.9 min上升到了13.3 min,粉质指数从56上升到192。复配杂粮面包粉流变学特性有很大程度改善,达到制作杂粮面包的粉质要求。     

麦麸细粉营养成分分析及在面包烘焙中的应用

采用喷雾调质、研磨和筛选分离出小麦麸皮中的麦麸细粉,分析其营养成分,并通过流变特性测试及烘焙应用试验,研究其对面粉营养成分及面团烘焙特性的影响。结果表明,分离所得麦麸细粉的蛋白质和膳食纤维含量高达15.8%和33.6%,且富含钾、钙、铁等多种矿物质。随着麦麸细粉在面包专用粉中添加比例的增加,面包专用粉的灰分和湿面筋含量呈递增趋势;面筋指数、糊化黏度逐渐降低,面团吸水率、弱化度逐渐增加;稳定时间、延展性呈减小趋势;面包的搅拌时间、发酵时间延长,比容和品质评分降低。添加10%麦麸细粉的面包烘焙性能和感官品质较好,且营养价值得到了显著改善。     

苦荞粉添加量对面团性质及馒头品质的影响

通过添加不同量的苦荞粉配成苦荞-小麦混粉,研究混粉揉混特性、面团微观结构的变化以及苦荞馒头的感官品质。结果表明,当添加量在5%~15%时,揉混结果中的和面时间和峰值面积变化不大,微观结构中蛋白质面筋网络结构略微减弱,但当添加量达到20%后,和面时间和峰值面积都有大幅度降低,微观面筋网络结构也出现明显的下降。同时,苦荞粉添加量为15%时馒头感官品质较好。综合分析可知,添加量为15%时苦荞馒头仍具有较好的品质。     

Effect of hydrocolloids on gluten‐free batter properties and bread quality

The objectives of this study were to assess the effect of the addition of different hydrocolloids on gluten‐free batter properties and bread quality and to obtain information about the relationship between dough consistency and bread quality. Breads were made of rice, corn and soy flours and 158% water. Following hydrocolloids were added: carrageenan (C), alginate (Al), xanthan gum (XG), carboxymethylcellulose (CMC) and gelatine (Gel). Batter consistency, bread specific volume (SV), crumb analysis, crust colour, crumb hardness and staling rate were determined. Hydrocolloids increased batter consistencies: the highest value was obtained with XG, which doubled that of control batter, followed by CMC. Breads with hydrocolloid presented higher SV than control, especially with XG whose SV was 18.3% higher than that of control bread. A positive correlation was found between SV and batter consistency (r = 0.94; P < 0.05). Crumbs with Gel, XG and CMC presented higher cell average size. XG and CMC crumbs looked spongier. Breads containing hydrocolloid evidenced lighter crusts. Crumb firmness was decreased by XG and CMC addition, and staling rate was slower. Overall, XG was the hydrocolloid that most improved gluten‐free bread quality. These results show that, in formulations with high water content, batter consistency is strongly associated with bread volume.