Preparation of lactic acid bacteria compound starter cultures based on pasting properties and its improvement of glutinous rice flour and dough

The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,and breakdown value to prepare LAB compound starter cultures.The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour.In particular,the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour.Moreover,the gelatinization enthalpy of the fermented samples increased significantly.For frozen glutinous rice dough stored for 28 days,the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough,and the freezable water content was lower than that of control dough.These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry,which has significance for its application.

Influence of Production Factors on the Physico-Chemical Characteristics of Fermented Cassava Dough and Sensory Evaluation of Attieke

Attieke is an Ivorian semolina which obtained by fermenting, pressing and steaming cassava dough. Attieke production remains a traditional activity carried out by less literate women. However, perceived differences in measurable factors and attieke qualities require an investigation of their influence on the characteristics of the pressed dough and attieke. The aim of this study is to improve the quality of the dough in relation to that of the attieke produced. The experiment was carried out on 4 production factors, namely the type of boiled or braised ferment, the incorporation rate of the ferment between 8 and 10%, the addition of oil from 0.1 to 1% and the fermentation time from 12 to 15 hours applied to the Improved African Cassava (IAC) variety. A complete experiment design of 16 samples of fermented dough and attieke was employed. These samples underwent physic-chemical analyses for the fermented dough and sensory evaluation for the attieke. It was found that, except for titratable acidity, reducing sugar content and ash content, the physico-chemical characteristics of the dough of IAC variety were significantly influenced by all production factors and their interaction. Fermentation time significantly influences 60% of the physico-chemical characteristics of the fermented dough. The type of ferment, the oil addition and the ferment rate have a significant influence at 40% of these characteristics. At the sensory level, color, acidity and grain binding with an explained variance of 34.60% were essential for the appreciation of the attieke samples. Thus, these production factors could be considered for the improvement of the fermented dough and attieke production process.

Effect of Gum Arabic from Acacia senegal var. kerensis as an Improver on the Rheological Properties of Wheat Flour Dough

Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to increasing consumer awareness, thus contributing to the rising demand for natural hydrocolloids. Gum Arabic from Acacia senegal var. kerensis is a natural gum exhibiting excellent water binding and emulsification capacity. However, very little is reported on how it affects the rheological properties of wheat dough. The aim of this study was therefore, to determine the rheological properties of wheat dough with partial additions of gum Arabic as an improver. Six treatments were analyzed comprising of: flour-gum blends prepared by adding gum Arabic to wheat flour at different levels (1%, 2% and 3%), plain wheat flour (negative control), commercial bread flour and commercial chapati flour (positive controls). The rheological properties were determined using Brabender Farinograph, Brabender Extensograph and Brabender Viscograph. Results showed that addition of gum Arabic significantly (p chapati. These findings support the need to utilize gum Arabic from Acacia senegal var. kerensis as a dough improver.

紫米粉和羊肚菌粉添加对面团及面包品质的影响

为了满足人们对面包产品多样化、功能化的需求,通过添加不同比例紫米粉(0、3%、6%、9%和12%)和羊肚菌粉(0和3%)替代小麦面粉用于制作面包,测定了面团流变学特性、膳食纤维含量、面包焙烤特性、淀粉体外消化能力以及风味物质含量。结果表明:紫米粉和羊肚菌粉的添加改善了面团的流变特性,面团的储存模量和损耗模量随之上升,tanδ值缓慢下降。紫米粉和羊肚菌粉的添加显著(P<0.05)提高了面包膳食纤维含量,却使比容、弹性和凝聚力下降,硬度和咀嚼性显著(P<0.05)增大。当3%羊肚菌粉替代量不变,紫米粉从0增加到12%,面包皮和面包芯的L*值逐渐下降,ΔE逐渐增加,颜色偏暗。此外,添加紫米粉和羊肚菌粉可以有效降低面包的淀粉水解率。电子鼻测定结果表明,紫米羊肚菌面包的风味物质主要为醇类、芳香类、脂肪烃类和酯类,面包风味丰富。因此,使用适量紫米粉和羊肚菌粉替代小麦粉,有效提高了面包品质和特性,为功能型面包的开发提供有益参考。

大豆蛋白对面团中醇溶蛋白组成和结构的影响研究

大豆蛋白加入小麦粉中改善面制品营养品质的同时也会对面团的面筋蛋白组成和结构产生影响。醇溶蛋白是小麦面筋的主要组分,赋予面团黏性和延伸性。为探究大豆蛋白对面团中醇溶蛋白的影响,将大豆分离蛋白(soy protein isolate,SPI)、大豆浓缩蛋白(soy protein concentrate,SPC)、质构化大豆蛋白(texturized soy protein,TSP)分别以不同比例添加到小麦粉中制成面团,分离醇溶蛋白,通过内源荧光光谱、紫外光谱扫描及酸性聚丙烯酰胺电泳等方法对面团中醇溶蛋白的结构和组成进行评价。结果表明,与小麦粉面团相比,添加8%(质量分数,下同)的SPI、SPC、TSP后,面团中醇溶蛋白相对含量分别下降了9.65%、9.85%、5.97%;添加8%的SPI后,面团α-醇溶蛋白比例增加0.79%,β-,γ-醇溶蛋白比例无显著性变化,ω-醇溶蛋白比例下降2.27%;添加8%的SPC后,面团α-醇溶蛋白比例下降1.42%,β-醇溶蛋白比例下降1.59%,γ-醇溶蛋白无显著性变化,ω-醇溶蛋白比例增加3.25%;添加8%的TSP后,面团α-醇溶蛋白比例下降1.47%,β-,γ-醇溶蛋白比例无显著性变化,ω-醇溶蛋白比例增加1.12%。添加SPI和TSP均能使面团中醇溶蛋白肽链伸展,α-螺旋含量降低;添加SPI使面团中醇溶蛋白β-转角含量降低;添加SPC对面团中醇溶蛋白结构无显著影响。综上,添加大豆蛋白使面团中醇溶蛋白相对含量下降,肽链结构伸展,蛋白组分发生变化,从而改变醇溶蛋白黏附在麦谷蛋白骨架的状态,增大面团拉断力,缩短面团拉伸距离。该研究建立了一种探究面团中醇溶蛋白组成和结构的方法体系,为植物源蛋白在面制品中的应用提供理论基础和新思路。

青稞β-葡聚糖对不同筋力小麦面团劣变的影响机制研究

分别在高筋小麦粉和低筋小麦粉中添加青稞β-葡聚糖制作复配面团,分析青稞β-葡聚糖添加量对高筋、低筋小麦面团热机械性能、糊化特性以及面筋蛋白组成的影响,并探讨青稞β-葡聚糖对不同筋力小麦面团劣变的影响机制。结果表明:随着青稞β-葡聚糖添加量的增加,复配粉面团的热机械学性能发生变化,吸水率、黏度崩解值和蛋白质弱化度总体增加;形成时间呈现先延长后缩短的趋势,最大黏度指数呈降低趋势;高筋、低筋小麦粉糊化的峰值黏度、谷值黏度、最终黏度、崩解值和回生值总体上均呈现下降趋势。热机械参数与糊化参数的相关性分析表明,回生值、最大黏度指数、稳定时间均与峰值黏度、谷值黏度、崩解值和最终黏度均呈极显著正相关;SDS-PAGE电泳试验结果显示,面筋蛋白条带的数量和位置没有变化但强度降低。研究表明,在小麦粉中添加青稞β-葡聚糖抑制了小麦淀粉糊化,阻碍了淀粉分子重排,使面筋蛋白劣化,降低了复配面团稳定性,但延缓了小麦淀粉的回生老化,从而延长了复配面团的贮藏时间。

Variation and trends in dough rheological properties and flour quality in 330 Chinese wheat varieties

The objective of this study was to investigate variation and trends in dough rheological properties and flour quality traits in 330 Chinese wheat varieties. The dough rheological properties of development time(DT), stability time(ST), and farinograph quality number(FQN)were evaluated, as well as the flour quality traits of protein(PC), wet gluten content(WGC), and sedimentation value(SV). The coefficients of variation of DT(40.5%), ST(58.1%), and FQN(42.4%) were higher than those of PC(9.1%), WGC(10.1%), and SV(15.3%). Normal distributions were observed for the flour quality indices but not for the rheological parameters. SV was strongly correlated with the three rheological parameters and accordingly might be used as a primary indicator for dough rheological property evaluation. Our results showed that there has been marked improvement in dough rheological properties for Chinese wheat varieties released since 1986, while flour quality has remained stable.

Study on the effect of wheat bran dietary fiber on the rheological properties of dough

The aim of the study was to determine the influence of wheat bran dietary fiber on wheat flour dough rheological properties.In this paper,wheat bran dietary fiber(WBDF)with different levels(0,3%,6%,9%,12%)were added to wheat flour and the characterization of dough rheological properties was conducted by rapid visco-analyzer,farinograph,as well as rotational rheometer.The results from pasting properties showed a gradual reduction in peak viscosity,trough viscosity,final viscosity and setback with increasing WBDF content.At high WBDF concentration,the significant increase of water absorption,formation time as well as weakening degree implied the harder formation of gluten network structure and the competition for water between gluten and WBDF particles.Such conclusion was in line with the findings from dynamic rheology tests,in which the doughs containing WBDF were more sensitive to strain regardless of their rigid and stiff texture.This study revealed vulnerable dough structure induced by WBDF,as well as the strengthened elastic property,elaborating the harmful effects ofWBDF on the rheological properties of doughs.

Comparison of Different Dough Rheological Measurement and Path Coefficient Analysis of Bread Quality

Farinograph, extensograph and mixograph are the special instruments used to determinedough rheological characteristics. In this study, twenty-seven wheat cultivars ofdifferent gluten strength were used to study the correlations among each rheologicalparameter determined by above instruments. Multiple linear regression analysis and pathcoefficient analysis were used to study the direct and indirect effects of 11 doughrheological characteristics on bread quality. The results showed significant correlationsamong the principal parameters. There were significantly or extremely significantlypositive correlations among development time (DT), stability time (ST), farinographquality number (FQN) of farinograph, area, maximum resistance (Rmax), viscoelastic ratio(Rmax/E)of extensograph and mixing time (MT), 8-minute-curve-tail (8MCT) of mixograph.These indexes affected bread-making quality either directly or indirectly. Of all theindexes, ST, maximum Rmax, MT and FQN were the most important ones.

Use of two-stage dough mixing process in improving water distribution of dough and qualities of bread made from wheat–potato flour

The two-stage dough mixing process was innovated to improve the qualities of bread made from potato flour(PF) and wheat flour at a ratio of 1:1(w/w). The final dough was first prepared from wheat flour before being added with PF. The effects of the method on enhancing the dough qualities were verified, and the distribution of water in gluten-gelatinized starch matrix of the doughs was investigated. We observed that the bread qualities were improved, as reflected by the increase of specific volume from 2.26 to 2.96 m L g^–1 and the decrease of crumb hardness from 417.93 to 255.57 g. The results from rheofermentometric measurements showed that the dough mixed using the developed mixing method had higher maximum dough height value, time of dough porosity appearance, and gas retention coefficient, as well as enhanced gluten matrix formation compared to that mixed by the traditional mixing method. The results from low-field nuclear magnetic resonance confirmed that the competitive water absorption between gluten and gelatinized starch could restrict the formation of gluten network in the dough mixed using the traditional mixing process. Using the novel mixing method, gluten could be sufficiently hydrated in stage 1, which could then weaken the competitive water absorption caused by gelatinized starch in stage 2;this could also be indicated by the greater mobility of proton in PF and better development of gluten network during mixing.

Effects of Sourdough Addition on the Quality and Shelf Life of Chinese Steamed Bread

The effect of adding sourdough with lactic acid bacteria(Lactobacillus plantarum M616) on dough quality and the sensory scores, specific volume, crumb firmness, and spread ratio of resultant Chinese steamed bread were studied. The moisture content of crumb and texture characteristics of the Chinese steamed bread with sourdough during storage were analyzed. In this study, 10%,20%, 30%, and 40% of sourdough addition was investigated. The sourdough starter resulted in significant decrease in the water absorption, development time, stability, and farinograph quality number of the dough. The addition of sourdough improved the quality of Chinese steamed bread such as improving the sensory scores and specific volume, decreasing the crumb firmness, and a lower spread ratio was observed with an increase in the sourdough concentration up to 30%. Sourdough addition delayed a fast decrease in the moisture content of the Chinese steamed bread crumb during storage. The texture profile analysis of the bread crumb indicated that the addition of sourdough improved the quality and delayed the staling speed of Chinese steamed bread during storage.Moreover, inclusion of 30% sourdough produced the best protective effect on product staling.

Quality deterioration and improvement of wheat gluten protein in frozen dough

Frozen dough technology can effectively recover sensory quality of frozen flour products.This technique has gradually drawn the research interest in the industrialization of staple food.However,the quality of the final frozen products remains inferior to that of fresh products.This study reviewed the deterioration of gluten network in dough caused by ice recrystallization and various additives.This study also investigated the optimization of the freezing process and other empirical improvement techniques.Suggestions for future research were also provided.

The Variation and Stability Analysis of Wheat Dough Stability Time

Farinograph dough stability time is an important index for classifying wheat, and it often indicates the most appropriate end use for the wheat cultivars. This study aimed at the problem of large fluctuations in dough stability time that occurs during the commercial wheat production. The variations in the dough stability time and its consistency across locations and years were analyzed using 12 principal high-quality wheat cultivars （varieties） obtained from Shandong Province, China, which were grown at nine different locations for three successive years. The results showed that the coefficient of variation for the dough stability time ranged from 24.29 to 49.60% across different varieties, locations, and years. Additive main effects and multiplicative interaction （AMMI） analysis indicated that there were significant interactions for the dough stability time between the varieties, the growth locations, and the years. The genotype effect was the most noticeable, followed by the interaction of the genotype and the environment. The environmental effect was the least significant. The interactions between the varieties and the locations differ considerably, however, each cultivar （variety） apparently has a specific adaptability to the growth location. Therefore, for the successful commercial scale production of the high-quality wheat varieties, both the selection of proper cultivars and its most suitable growth locations to meet the desired requirements for the dough mixing stability time are important.

Effect of Pectins on Dough Rheology and Chinese Steamed Bread Quality

Dough preparation and performance are two critical factors influencing the final quality of wheat products. The influence of high and low methoxyl pectins on empirical and dynamic rheological properties of dough and Chinese steamed bread(CSB)quality were investigated. Different concentrations of high methoxyl apple pectin(HMAP), low methoxyl apple pectin(LMAP),and amidation apple pectin(ALMAP) were tested. Results from dynamic and empirical rheological tests indicated that all concentrations of pectins tested(0.2%, 0.6%, and 1%) negatively affected the gluten network. The low methoxyl pectins, LMAP and ALMAP, which had higher anionic densities, resulted in a pronounced weakening of the dough. Meanwhile, dough fermentation properties improved in the presence of appropriate pectins concentrations, and higher maximum dough height, stability of dough pore space, and gas retention were recorded. HMAP was the pectin most effective in influencing dough fermentation properties at all tested concentrations. Regarding CSB quality, textural properties, specific volume, moisture content, and water-holding capacity were analyzed. Generally, the textural properties of CSB were improved, including improved springiness and decreased hardness and chewiness, when 0.2%–0.6% HMAP or LMAP was used. The specific volume of CSB was increased by adding 0.2%–1% HMAP,0.6%–1% LMAP, or 0.2%–0.6% ALMAP. Moreover, CSB moisture loss was progressively reduced in the presence of different pectins at all tested concentrations during storage. In conclusion, pectins, especially HMAP, are good additives for improving the fermentation properties of dough and overall quality of CSB.

Recent advances in quality deterioration and improvement of starch in frozen dough

Starch with different particle sizes has different compositions and different physical and chemical properties.The amylopectin content and protein content and lipid content of small granule B starch are higher than that of A-type starch,which can form spiral complex to limit the expansion of starch.Under the same treatment conditions,B-type starch is more vulnerable to damage,sensitive to freezing storage,even breaks in freezing storage,and has higher gelatinization temperature than other starch during freezing.Amylose contained in A-type has high content,high crystallinity,high degree of ordering after frozen storage and insensitivity to frozen storage,which is beneficial to improve the stability of pores and texture of frozen dough.With the extension of freezing time,the content of amylose decreased,while the content of various amylopectin increased and the conformation of polysaccharide changed.Starch deterioration is different under different frozen storage conditions.The deterioration mechanism of frozen dough can be evaluated by variety of starch characteristics during freezing process,which is of great guiding significance to the improvement of frozen dough technology.

Effect of split applications of urea on protein size distribution, physical dough properties, and baking performance of five experimental bread wheat lines

Five experimental bread wheat lines (BWL) were grown at the Yaqui Valley Experimental Station in Sonora, México during two consecutive growing cycles. The effect of five nitrogen fertilization (NF) treatments on protein size distribution (PSD), physical dough properties (PDP), and baking performance of the BWL was evaluated. Polymeric and monomeric proteins were evalu-ated by SE-HPLC. PDP were carried out by the National Mixograph and the TA-XT2 Texture Analyzer. Baking performance was evaluated using the straight dough method. Protein content (PC), main protein fractions (glutenins, gliadins, albumins-globulins), and mixograph development time (MDT) were significantly influenced by NF treatment and BWL but not by their interaction. On the other hand, PDP measured by the Kieffer rig, and baking performance were significantly influenced by the main factors (NF and BWL) and their interaction. The amount and timing of fertilizer applied to the BWL modified the PC, PSD, PDP, and bread loaf volume. PDP exhibited a larger variation in comparison to the PSD of glutenins. The split application of 150 kg of urea/ha (50-50-50) to all BWL showed a better loaf volume response than the same amount of urea applied at sowing (150-0-0). The application of 300 kg of urea/ha to all BWL, either at sowing or at three split applications of 100 kg of urea/ha each, resulted in higher flour unextractable polymeric protein (FUPP). On the other hand, the split application of 100-100-100 kg of urea/ha to three of the BWL represented the higher total unextractable polymeric protein (TUPP). Differences on PC and PSD were reflected on differences on PDP and bread loaf volume observed among the BWL.

Improvement of whole wheat dough and bread properties by emulsifiers

Whole wheat bread is widely available worldwide,but it is always associated with less desirable dough processibility,small loaf volume,firm and gritty texture,and other distinctive attributes compared to white bread.Emulsifiers are commonly used to improve dough handling and baking quality during bread production.In present study,five emulsifiers(diacetyl tartaric acid esters of mono-and diglycerides(DATEM),polysorbate 80,sodium stearoyl lactylate(SSL),soy lecithin,and sucrose esters)were added during dough preparation of the whole wheat flour at 0.2%,0.5%,and 1.0%(flour weight basis).Dough rheological behavior and bread quality attributes,such as specific loaf volume and hardness,were measured.The results showed that DATEM,sucrose esters,and SSL increased the resistance to extension of the dough,whereas soy lecithin and polysorbate 80 increased the extensibility.Soy lecithin and polysorbate 80 were the only emulsifiers that significantly increased loaf volume compared to the control.Adding higher levels(1.0%)of sucrose esters,polysorbate 80,and SSL increased the formation of amylose-lipid complex and mitigate the crumb staling during storage.The results suggested that the emulsifiers could be applied to contribute to optimum functional quality of whole wheat bread.

Influence of high-molecular-weight glutenin subunit deletions at the Glu-A1 and Glu-D1 loci on protein body development, protein components and dough properties of wheat(Triticum aestivum L.)

High-molecular-weight glutenin subunits(HMW-GSs) play a critical role in determining the viscoelastic properties of wheat. As the organelle where proteins are stored, the development of protein bodies(PBs) reflects the status of protein synthesis and also affects grain quality to a great extent. In this study, with special materials of four near-isogenic lines in a Yangmai 18 background we created, the effects of Glu-A1 and Glu-D1 loci deletions on the development and morphological properties of the protein body, protein components and dough properties were investigated. The results showed that the deletion of the HMW-GS subunit delayed the development process of the PBs, and slowed the increases of volume and area of PBs from 10 days after anthesis(DAA) onwards. In contrast, the areas of PBs at 25 DAA, the middle or late stage of endosperm development, showed no distinguishable differences among the four lines. Compared to the wild type and single null type in Glu-A1, the ratios of HMW-GSs to low-molecular-weight glutenin subunits(LMW-GSs), glutenin macropolymer(GMP) content, mixograph parameters as well as extension parameters decreased in the single null type in Glu-D1 and double null type in Glu-A1 and Glu-D1, while the ratios of gliadins(Gli)/glutenins(Glu) in those types increased. The absence of Glu-D1 subunits decreased both dough strength and extensibility significantly compared to the Glu-A1 deletion type. These results provide a detailed description of the effect of HMW-GS deletion on PBs, protein traits and dough properties, and contribute to the utilization of Glu-D1 deletion germplasm in weak gluten wheat improvement for use in cookies, cakes and southern steamed bread in China and liquor processing.

The Effect of Oat Bran on the Dough Rheology and Quality of Chinese Steamed Bread

The present study investigates the effects of incorporating oat bran(OB) into Chinese steamed bread(CSB). Different levels(5%, 10% and 15%) of OB were used to replace wheat flour in the manufacture of CSB. The rheological properties of the dough were measured(water absorption(WA), development time, mixing tolerance, extensibility and stickiness). The addition of OB significantly increased WA, development time and stickiness, whereas decreased extensibility of dough. The physical properties of CSB were determined using specific volume, loaf height, moisture, and texture analysis. The nutritional quality of the bread was also analysed using an in vitro digestion method mimicking intestinal digestion. The results illustrated that the incorporation of OB into wheat flour decreases specific volume and softness of CSB. The addition of OB decreased the glycaemic response of steamed bread.This study illustrates the potential addition of OB to improve the nutritional quality of CSB.

Extraction of Dietary Fiber from Wheat Bran and Effects of Its Additives on Viscosity-elasticity of Noodle Dough

[ Objective] The aim was to study the optimum extraction condition of dietary fiber of wheat bran and to discuss its influence on viscosity-elasticity of noodle dough with added extracts. [ Methed] Influences of a-amylase, alkaline concentration, alkaline hydrolysis time and temperature on water holding capability and swelling capacity of dietary fiber were evaluated using single-factor test and orthogonal test. Effects of added dietary fiber from wheat bran on dough absorption ratio, rupture stress of dough and creep resistance were studied. [ Result] When the hydrolysis condi-tions of wheat bran were 0.4% a-amylase at 75 ℃ for 60 rain, further alkaline conditions were 5% sodium hydroxide for 60 min at 65 ℃, dietary fi-ber exhibited fine water holding capability and swelling capacity. The addition of 3%-5% dietary fiber from wheat bran into dough had little influence on the water absorption ratio of noodle, rupture stress of dough, creep resistance and can make functional noodle with rich dietary fiber from wheat bran. [Coonclusion] The study provided reference for the comprehensive utilization of wheat bran and development of functional product.