UNIAXIAL COMPRESSIBILITY OF BLACKGRAM DOUGHS BLENDED WITH CEREAL FLOURS

The uniaxial compression characteristics of papad dough (moisture content 62%, dry basis), made from blackgram flour as well as after incorporation of different types of cereal (rice, sorghum and wheat) flours at different levels (20 and 40%), were determined. The stress-strain data can be interrelated by a power law type equation. The sensory attributes (stickiness, firmness, elasticity and ease of flattening/rolling) were correlated with the energy for compression, deformability modulus and apparent biaxial elongational viscosity. Inelastic doughs resulted from the blackgram dough; doughs with 20% rice or wheat blends were also inelastic but sorghum samples were elastic. The deformability modulus for sorghum doughs were extremely high. The blackgram dough as well as the wheat blended doughs were the easiest doughs to roll/flatten. Blended dough consisting of wheat flour (at 20 and 40% level) or rice flour up to 20% level was suitable for making cereal-blended papad doughs.     

Effect of flour extraction rate and baking process on vitamin B1 and B2 contents and antioxidant activity of ginger-based products

The effect of flour extraction rate and baking on thiamine (vitamin B₁) and riboflavin (vitamin B₂) content and antioxidant capacity of traditional ginger cake was studied and then compared to white wheat bread. Ginger cake was formulated either with whole-grain (100% extraction rate) or with brown (92% extraction rate) rye flour and baked at 180 °C for 18 min. The antioxidant capacity was evaluated in terms of radical scavenging activity against peroxyl (ROO·) and superoxide anion radicals (O ₂ ^·? ). Thiamine content in rye doughs (F-100% and F-92%) was found to be 38% lower when compared to wheat dough. In contrast, whole-grain and brown rye doughs exhibited an almost fourfold higher riboflavin content than wheat dough. Rye dough baking led to reductions in thiamine (from 53 to 65%) and riboflavin (from 69 to 71%) contents. Likewise, thiamine and riboflavin contents in wheat dough were also reduced (56 and 10%, respectively) after baking; however, ginger cake with whole-grain rye flour exhibited significantly higher thiamine and riboflavin contents. Rye doughs and ginger cakes showed higher scavenging activities against ROO· radicals when compared to that of wheat dough and bread. Thus, baking significantly enhanced ROO· scavenging properties of ginger cakes while only a slight increase was observed in wheat bread. In contrary, baking gave rise to a decrease in SOD-like activity both in ginger cake or wheat bread. Our findings suggest that formulation with whole-grain rye flour can potentially increase B₁ and B₂ vitamin contents as well as the ROO· scavenging capacity of traditional ginger cake.     

A farinograph study on the viscoelastic properties of sago/wheat flour dough systems

Doughs containing mixtures of sago and wheat flours of differing protein content at different levels of sago substitution (10, 15, 20, 25, 30, 40 and 50%) were prepared as follows: sago + high protein wheat (HPW) flour, sago + medium protein wheat (MPW) flour and sago + low ? protein wheat (LPW) flour. The viscoelasticity of doughs from control sago and wheat flours and sago/wheat flour mixtures was determined using a Braberder farinograph. It was found that arrival time increased with increasing protein content in the mixture. Peak time for control wheat flours and sago/wheat flour mixtures increased with increasing protein content. Dough stability, 20 min drop and water absorption were found to decrease as the sago proportion in the mixture decreased. The 50% sago/LPW mixture was unable to form a dough. Breakdown times for control HPW flour and HPW flour mixtures were the highest, followed by MPW flour and then LPW flour. However, breakdown time for control MPW flour was higher than that for HPW flour mixtures. The same trend was observed at all ratios of mixture over the whole experiment. Copyright © 2004 Society of Chemical Industry     

Enzymatic Reduction of Phytate in Whole Wheat Breads

The presence of phytate in flour may be responsible for reduced bioavailability of iron, magnesium, zinc, and calcium from bread. The effect of various concentrations of commercial phytase or phosphatase added to whole wheat flour-yeast doughs on their phytate and nonphytate phosphorus content has been investigated. By using 2.0% (flour basis) of phytase and 0.11% phosphatase the initial phytate phosphorus concentration of the dough was reduced to 1/8 and 1/12 of its initial values, respectively. Storage of the whole wheat breads for up to 96 hr at room temperature showed further significant reduction of phytate phosphorus. The phytate phosphorus content of yeast leavened whole wheat breads decreased during 2 hours of dough fermentation, baking and the subsequent 48 hours of storage at room temperature from 24 mg/100g dough (dry matter) to 1.7 mg/100g bread (dry matter); the phytate phosphorus continued to decrease and after 96 hours storage it was 0.6 mg/100g bread.     

Water Content, Water Soluble Fraction, and Mixing Affect Fundamental Rheological Properties of Wheat Flour Doughs

Fundamental rheological behavior of wheat flour doughs were compared with empirical results from a farinograph. Water contents of 42-47% and mixing times of 8, 16, and 24 min were examined. The storage modulus, G′, decreased when water content was increased from 42 to 45%. Dough produced from water extracted flours had high G′ and low δ. Increasing water content or mixing time decreased G′. There was a linear relationship (slope = 0.30) between G′ and the farinogram peak height for the reconstituted (water-soluble fraction added back), flour-water, and freeze-dried flour-water doughs. The extracted flour doughs also showed a linear relationship between G′ and farinogram peak height with slope = 1.07.     

糯麦粉对冷冻面团发酵流变特性和面包烘焙特性的影响

采用发酵流变测定仪和质构分析仪研究不同比例的糯麦粉对冷冻面团发酵流变学特性和面包烘焙特性的影响。结果表明：无论面团冷冻与否,随着糯麦比例增加,面团发展的最大高度(Hm)和持气率(R)逐渐下降,而气体释放曲线最大高度(H＇m)和CO2产气量(Vco2)在一定程度上增加。随着冻藏时间的延长,面团各种参数(Hm、H＇m、R等)逐渐降低,但是下降的幅度随糯麦粉添加量的增加而减小,如与冻藏7d相比,添加质量分数0%、10%、20%和30%的糯麦面团经冻藏60d后Hm分别下降了12.9%、9.6%、7.7%和7.5%,而R则分别下降了2.8%、2.1%、1.6%和1.7%。在冷冻贮藏过程中,面包品质虽有一定程度的下降,但添加糯麦粉的面包品质下降程度较慢,抗老化效果好,且由感官评定可知,冻藏不同天数后,添加10%糯麦粉的面包最易受人们喜爱。     

Effect of β-Glucan Concentrate on the Water Uptake,Rheological and Textural Properties of Wheat Flour Dough

The effects of the addition of β-glucan concentrate (2.5–10 g/100 g flour) and water (58–70 mL/100 g flour) on the rheological and textural properties of wheat flour doughs were studied. Various empirical (farinograph, extensograph, dough inflation, and dough stickiness) and fundamental rheological tests (oscillatory and creep-recovery) were employed to investigate composite dough structure and an attempt was made to correlate the data obtained from different instrumental measurements. The water absorption increased with the addition of β-glucan concentrate into wheat flour. An increase in mixing time and stability were recorded upon addition of β-glucan concentrate (≤ 5 g/100 g flour), and the extensibility decreased at similar condition. The composite dough exhibited predominating solid-like behavior. The mechanical strength, dough stickiness, the peak dough inflation pressure decreased with increasing water content but those parameters increased with β-glucan concentrate incorporation within the studied concentration range. Creep-recovery tests for 5 g β-glucan concentrate/100 g flour doughs recorded less resistance to deformation with an increase in water level and data were well described by the Burger model. Thermal scanning of doughs revealed that the protein denaturation peak was significantly influenced by water content, and the values were ranged between 110 and 124°C. Significant relationships between empirical and fundamental rheological testing methods were found.     

麦麸超微粉对面团特性及制品品质的影响

对超微粉碎麦麸粉面团的流变学特性进行研究,分别将超微粉碎麦麸(添加质量分数分别为0%、5%、10%、15%、20%)添加到面粉中并调制成面团,测定并记录其粉质特性和拉伸特性等。结果表明：麦麸超微粉的添加会使面粉的吸水率增大,面团形成时间、弱化度均有所增加,面团的稳定时间呈下降趋势;从粉质特性总体来看,超微麦麸粉的添加能改善面粉的粉质特性。在麦麸超微粉添加量在10% 时,麦麸超微粉馒头样品模糊综合评价结果为良好,其色泽、气味、组织结构、口感都可以被人接受。     

Fortification of wheat flour with black soldier fly prepupae. Evaluation of technological and nutritional parameters of the intermediate doughs and final baked products

Bread wheat flour presents specific nutrient deficiencies, such as some essential amino acids and this drawback could be tackled by adding ingredients that contain them in high amounts. Therefore, this study aims at developing new types of flours as well as at analysing enriched flours and baked derived products, which combine the compositional and sensory characteristics of wheat bread with some peculiar nutritional properties of black soldier fly prepupae (Hermetia illucens). These composite flours were obtained by mixing “Italian type 1” semi-whole wheat flour (W = 300) with flour obtained from prepupae of black soldier fly (20 g and 40 g/1 kg composite flour). Chemical, physical, and rheological analyses were carried out for each of the flour mixtures. Moisture, ash, gluten, total protein content, falling number, strength, tenacity, extensibility, amino acid profile of doughs and breads were analysed as well. An increase in the content of essential amino acids in doughs and baked products was obtained and also led to an improvement in bread texture.     

RHEOLOGY OF WHEAT DOUGHS FOR FRESH PASTA PRODUCTION: INFLUENCE OF SEMOLINA-FLOUR BLENDS AND SALT CONTENT

Dynamic measurements were made with a controlled stress rheometer to study the viscoelastic properties (G', G', δ) of wheat doughs (45% wb water content) for fresh pasta production prepared with different blends of durum wheat semolina and common wheat flour with different concentrations of sodium chloride. Increasing the semolina and sodium chloride content, increased the strength and the solid-like behaviour of semolina-flour blends. The physical properties of dough were strongly dependent on particle size distribution and salt addition. By manipulating semolina-flour ratio and ionic strength, it was possible to obtain semolina-flour doughs with a rheological behaviour close to that of pure semolina dough.     

Suitability of various australian wheats for chinese-style steamed bread

Three methods of preparation of steamed bread on a laboratory scale were evaluated to determine the one most suitable for discriminating between flour samples. The preferred method was then applied to a number of wheat varieties at different protein levels to select the most suitable ones for this product, and to determine the key analytical parameters of the most suitable flour. Flour colour and protein content appeared to be more important than other physical and chemical properties. Flour samples with high protein content (greater than 12%) and strong doughs gave bread with a wrinkled surface and dark colour, whereas low protein (less than 10%) soft wheat flours gave poor texture and eating quality, although the surface was smooth. It is suggested that flours of medium protein content (10–12%) and medium dough strength are the most suitable for steamed bread. Processing conditions affected steamed bread quality. Blending of high protein hard strong wheats with soft weak wheat could be practical for preparing flour for steamed bread.     

Influence of water and barley β-glucan addition on wheat dough viscoelasticity

The effects of the addition of two barley β-glucan isolates (0.2–1.0% of wheat flour), differing in molecular weight, and water (53–63% in a poor breadmaking wheat flour, cv. Dion, and 58–68% in a good breadmaking wheat flour, cv. Yekora) on the viscoelastic properties of wheat flour doughs were investigated. A response surface model (CCF) was used to evaluate the effects observed on the dynamic and creep-recovery parameters of the dough. The evaluation was done separately for each combination of β-glucan isolate (BG1 of ～10⁵ Da and BG2 of ～2 × 10⁵ Da) and flour type. Besides the contents of β-glucan and water, the molecular size of the polysaccharide and the flour quality were important determinants of the dough’s viscoelastic behavior. Compared to BG1, the higher molecular weight β-glucan (BG2) brought about major changes on all the rheological responses of the fortified doughs. The addition of appropriate levels of β-glucans and water in the poor breadmaking cultivar (Dion) doughs could yield similar viscoelastic responses to those observed by a non-fortified good breadmaking quality flour dough (Yekora).     

Enrichment of Antioxidant Capacity and Vitamin E in Pita Made from Barley

This study aimed to enhance total antioxidant and vitamin E content of pita bread, by replacing 50% of the standard baker's flour with flours milled from covered (WI2585 and Harrington) or hulless (Finniss) barley genotypes, previously shown to have high antioxidant and vitamin E levels at harvest. Pita breads were made from either 100% baker's flour (control) or 50% malt flour, whole‐grain flour, or flour from barley grains pearled at 10%, 15%, and 20% grain weight. Antioxidant capacity and vitamin E content of flours and pitas were determined by their ability to scavenge 2,2‐diphenyl‐1‐picrylhydrazyl radicals and high performance liquid chromatography, respectively. The physical and sensory properties of the pitas were also assessed. All pitas made from either whole grain or pearled barley flour had a higher antioxidant capacity and most also had higher vitamin E content than standard pita. The antioxidant and vitamin E levels were reduced in pearled compared to whole grains, however the extent of that reduction varied among genotypes. The greatest antioxidant and vitamin E levels were found in pita made from malt flour or Finniss whole grain flour. Furthermore, sensory analysis suggested these pitas were acceptable to consumers and retained similar physical and sensory properties to those in the control pita.     

Stability of DON and DON-3-glucoside during baking as affected by the presence of food additives

The mycotoxin deoxynivalenol (DON) is one of the most common mycotoxins of cereals worldwide, and its occurrence has been widely reported in raw wheat. The free mycotoxin form is not the only route of exposure; modified forms can also be present in cereal products. Deoxynivalenol-3-glucoside (DON-3-glucoside) is a common DON plant conjugate. The mycotoxin concentration could be affected by food processing; here, we studied the stability of DON and DON-3-glucoside during baking of small doughs made from white wheat flour and other ingredients. A range of common food additives and ingredients were added to assess possible interference: ascorbic acid (E300), citric acid (E330), sorbic acid (E200), calcium propionate (E282), lecithin (E322), diacetyltartaric acid esters of fatty acid mono- and diglycerides (E472a), calcium phosphate (E341), disodium diphosphate (E450i), xanthan gum (E415), polydextrose (E1200), sorbitol (E420i), sodium bicarbonate (E500i), wheat gluten and malt flour. The DON content was reduced by 40%, and the DON-3-glucoside concentration increased by >100%, after baking for 20 min at 180°C. This confirmed that DON and DON-3-glucoside concentrations can vary during heating, and DON-3-glucoside could even increase after baking. However, DON and DON-3-glucoside are not affected significantly by the presence of the food additives tested.     

STUDIES ON THE DEVELOPMENT OF PAN BREAD USING RAW WHEAT GERM

Raw wheat germ, known to be high in vitamin E and other phytochemicals, was used to develop pan bread formulations. The raw wheat germ used had protein, fat and ash contents of 27.88, 9.86 and 4.33%, respectively, compared with 11.35, 1.26 and 0.61% for white flour. Reduction in specific loaf volume, due to the inclusion of wheat germ, was significantly restored by using a combination of 30 ppm potassium bromate and 50 ppm ascorbic acid. At levels of 10 and 20% germ incorporation, the use of 3.0% enzyme‐active soy flour significantly improved the specific loaf volume of the test breads. In comparison with white‐flour control bread, panelists did not find any significant differences in any of the sensory attributes of the test bread samples containing up to 10% wheat germ and 0.5% sodium stearoyl‐2‐lactylate (SSL). The minerals, protein and fat content of wheat‐germ‐enriched breads, was superior to the white‐flour control bread. It can be concluded that phytochemical‐enriched pan bread with superior nutritional and sensory qualities can be produced using white flour, 20% wheat germ, 0.5% SSL, 30 ppm potassium bromate and 50 ppm ascorbic acid.     

INFLUENCE OF THE STARCH GRANULE SURFACE ON THE RHEOLOGICAL BEHAVIOUR OF WHEAT FLOUR DOUGH

The influence of the properties of the starch granule surface on the rheological behaviour of wheat flour doughs was studied in dynamic oscillation measurements (frequency sweep and strain sweep) and in stress relaxation measurements. A flour with a high protein content (15%) was diluted with wheat starch to obtain a protein content of 10%. The granule surface of the substituted starch was modified in three different ways: by heat treatment, by adsorption of a wheat protein fraction and by adsorption of lecithin to the granule surface. The effects of these modified starches were compared with the results obtained for nonmodified starch and protein or lecithin (in liposomes) added to the flour. Owing to the low concentration of the added protein and lecithin, no effect was observed when they were added to the bulk of flour. However, as a starch-surface modification the same components influenced the rheological parameters studied. Also the heattreated starch had an effect on the rheological behaviour. The study established the importance of the properties of the starch-granule surface in wheat flour dough.     

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.     

Water Binding of Wheat Flour Doughs and Breads as Studied by Deuteron Relaxation

Water mobility in wheat flour doughs and breads was investigated by deuteron relaxation using pulsed NMR. Water was replaced by deuterium oxide in dough and bread at different concentrations. Mixograms indicated that wheat flour associated more strongly with D₂O than it did with H₂O. Varying the D₂O:H₂O ratio of flour doughs had no effect on the longitudinal (T₁) or transverse (T₂) relaxation times of deuteron. Hard wheat and soft wheat flour doughs showed similar increases in T₁ and T₂ with increasing moisture content. Staling of bread crumb was accompanied by decreased T₁ and T₂, indicating an overall decrease in water mobility and increase in water binding. The decrease in water mobility of bread crumb with storage time was shown to be independent of reduction in moisture content.     

Effect of soy addition on microwavable pocket-type flat doughs

Microwavable frozen baked goods are widely used by the food industry. However, the altered heat and mass transfer patterns associated with microwave radiation result in tough and rubbery baked products due to reduced plasticization of the polymers. Ingredients with high water-holding capacity and high content of polar lipids have been shown to enhance gluten plasticization and to improve water retention. Therefore, this study explored the physicochemical changes imparted by microwave baking of pocket-type flat doughs with and without soy added at 10%, 20%, and 26% and compared these to their conventionally baked counterparts. Microwave baking resulted in a soft, rubbery, and tough wheat product with increased "freezable" water. Soy was added to the formulation as a means to improve polymer plasticization. Conventional baking of soy doughs resulted in rubbery and tough products due to changes in water state and mobility (freezable water approximately 15 compared with 7.09 of the control). However, soy reduced the cohesiveness of the microwave baked products reaching the lowest value at 20% soy addition (cohesiveness 0.33 ± 1, comparable to that of the conventionally baked control). These data suggest that reduction of water mobility induced by soy proteins and polar lipids (confirmed by thermogravimetric analysis [TGA] and 1H nuclear magnetic resonance [1H NMR]) possibly plasticized the starch-gluten network of microwave baked soy doughs. Thus, soy was shown to improve the texture of microwave baked pocket-type flat doughs although further formula optimization is warranted. PRACTICAL APPLICATION: Microwavable pocket-type flat doughs are used frequently by the food industry to enrobe meat, vegetable, and sweet items for convenient meal delivery. Microwave heating of such doughs induces the development of crustless products compared to conventionally baked products, resulting in a tough and rubbery texture. Partial substitution of wheat flour with soy, in the form of soy flour and soy milk powder, prevented the deleterious textural changes associated with microwave heating. These results suggest that soy is a functional ingredient for the textural improvement of microwavable pocket-type flat doughs.     

两种制粉方式对紫粒小麦营养功能成分的影响

采用机械分层碾磨和石磨制粉2种加工方式,对"贵紫4号"紫粒小麦加工的面粉和麸皮进行淀粉、粗蛋白、脂肪、粗纤维、维生素、矿物质、氨基酸、总酚、花青素等营养功能成分的对比分析。结果表明,机械分层碾磨和石磨制粉,对面粉和麸皮的营养功能成分影响显著(P<0.05),机械一等粉和机械麸皮的常规营养成分、钙、铁、锌和维生素含量分别高于石磨面粉和石磨麸皮,而石磨面粉的硒含量比机械一等粉高113.90%,石磨制粉的花青素含量比机械制粉高4.90%,说明2种加工方式各有优缺。从氨基酸组成看,"贵紫4号"紫粒小麦的AAS评分高于普通小麦9.70%,且麸皮中的赖氨酸评分大于1(变为非限制性氨基酸),花青素含量达2 904.93 mg/kg,是麸皮入粉进行全麦加工的优质原料。