Breadmaking and Storage of Various Wheat Fractions Affect Vitamin E

The vitamin E loss during baking of two types of industrially baked breads was studied. Neither scalding nor fermentation reduced the vitamin E content. However, the sour dough preparation and dough-making resulted in 20-60% reduction in the content of tocopherols and tocotrienols. In addition the vitamin E yield in the doughs and the French bread when using two different extraction methods were compared. The two methods showed similar results for flours and doughs, but indicated differences after the baking stage. Storage stability of wholemeal flour, white flour, bran and germ of wheat were also investigated. Storage at 20°C for 12 mo decreased vitamin E activity of the various wheat fractions by 28-40%.     

Discrimination of Volatiles of Refined and Whole Wheat Bread Containing Red and White Wheat Bran Using an Electronic Nose

Abstract: The principal objective of this study was to evaluate the capability of electronic (E) nose technology to discriminate refined and whole wheat bread made with white or red wheat bran according to their headspace volatiles. Whole wheat flour was formulated with a common refined flour from hard red spring wheat, blended at the 15% replacement level with bran milled from representative samples of one hard red and 2 hard white wheats. A commercial formula was used for breadmaking. Results varied according to the nature of the sample, that is, crust, crumb, or whole slices. Bread crust and crumb were completely discriminated. Crumb of whole wheat bread made with red bran was distinct from other bread types. When misclassified, whole wheat bread crumb with white bran was almost invariably identified as refined flour bread crumb. Using crust as the basis for comparisons, the largest difference in volatiles was between refined flour bread and whole wheat bread as a group. When refined flour bread crust was misclassified, samples tended to be confused with whole white wheat crust. Samples prepared from whole bread slices were poorly discriminated in general. E‐nose results indicated that whole wheat bread formulated with white bran was more similar in volatile makeup to refined flour bread compared to whole wheat bread made with red bran. The E‐nose appears to be very capable to accommodate differentiation of bread volatiles whose composition varies due to differences in flour or bran type. Practical Application: Consumer preference of bread made using refined flour in contrast to whole wheat flour is partly due to the different aroma of whole wheat bread. This study used an electronic nose to analyze bread volatiles, and showed that whole wheat bread incorporating white bran was different from counterpart bread made using red bran, and was closer in volatile makeup to “white” bread made without bran. Commercial millers and bakers can take advantage of these results to formulate whole wheat flour with brans of preferred type in order to foster increased consumption of whole wheat products which confer many favorable health benefits.     

Effect of adding wheat bran and germ fractions on the chemical composition of high-fiber toast bread

The effect of the type of bran, level of addition, particle size and addition of wheat germ on the chemical composition of high-fiber toast bread was investigated. The bran and germ fractions were found to be high in ash, protein, fat and total dietary fiber contents. The wheat germ had a protein content of 27.88% compared with 11.35, 12.69 and 15.76% for white flour, whole wheat flour and red fine bran, respectively. The chemical composition of high-fiber breads, in terms of minerals, protein, fat and dietary fiber contents, was found to be far superior than that of the whole wheat flour (control) bread sample. Considering these results, it can be concluded that high-fiber toast bread, with lighter crumb color and improved sensory and nutritional qualities than the whole wheat flour bread, can be produced using white flour, and equal proportions of coarse and fine bran at 20%, germ at 7.5%, and sodium stearoyl-2-lactylate at 0.5% levels.     

Sensory evaluation of a hard white compared to a hard red winter wheat

Traditionally bread wheats grown in the USA have been hard red genotypes. Introduction of hard white genotypes provides an opportunity for the comparison of the products and evaluation of consumer acceptance. MT 7811, a hard white wheat, and ‘Norwin’, a hard red winter wheat, were grown in adjacent plots in each of two years. Grain from each was divided, with half milled into whole wheat flour (wholemeal) and the other half milled into white flour (milled flour). Breads made from wholemeal and milled flour from each wheat genotype were tested by panelists for differences. Color differences were easily detected. The Wilcoxon-Mann Whitney rank sums test was used to evaluate signal detection data. Both crust and crumb differences between the two wheats could be detected by some panelists. Differences could be detected between the two wheat types in either wholemeal or milled flour bread. Crust differences were often greater than crumb differences. Trained panelists commented on some bitterness in red wheat products and a sweetness in white wheat products.     

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。     

Selenium concentration and speciation in biofortified flour and bread: Retention of selenium during grain biofortification,processing and production of Se-enriched food

The retention and speciation of selenium in flour and bread was determined following experimental applications of selenium fertilisers to a high-yielding UK wheat crop. Flour and bread were produced using standard commercial practices. Total selenium was measured using inductively coupled plasma-mass spectrometry (ICP-MS) and the profile of selenium species in the flour and bread were determined using high performance liquid chromatography (HPLC) ICP-MS. The selenium concentration of flour ranged from 30 ng/g in white flour and 35 ng/g in wholemeal flour from untreated plots up to >1800 ng/g in white and >2200 ng/g in wholemeal flour processed from grain treated with selenium (as selenate) at the highest application rate of 100 g/ha. The relationship between the amount of selenium applied to the crop and the amount of selenium in flour and bread was approximately linear, indicating minimal loss of Se during grain processing and bread production. On average, application of selenium at 10 g/ha increased total selenium in white and wholemeal bread by 155 and 185 ng/g, respectively, equivalent to 6.4 and 7.1 μg selenium per average slice of white and wholemeal bread, respectively. Selenomethionine accounted for 65–87% of total extractable selenium species in Se-enriched flour and bread; selenocysteine, Se-methylselenocysteine selenite and selenate were also detected. Controlled agronomic biofortification of wheat crops for flour and bread production could provide an appropriate strategy to increase the intake of bioavailable selenium.     

Deoxynivalenol and other Fusarium mycotoxins in bread,cake, and biscuits produced from UK-grown wheat under commercial and pilot scale conditions

Bread, cakes and biscuits were manufactured from flour containing deoxynivalenol (DON) and low concentrations of zearalenone (ZON) and nivalenol (NIV). The results show that these mycotoxins remain mostly unaffected during manufacture. Although the results indicate that the mycotoxins are largely stable and survive processing, when concentrations were determined on an ‘as is’ basis as stipulated in legislation, levels in finished products were usually lower than in the starting flour due to the dilution effect of other ingredients such as fat, sugar and water. Thus mean concentrations of DON in bread were reduced by about 35% and 39% in white and wholemeal bread respectively which are in close agreement with the reduction required by the regulations although the changes that occur during milling white and wholemeal flour from whole wheat also need to be taken into account. The reduction of DON during cake manufacture is greater than for bread because flour makes up only about 25% of the starting ingredients. However, in biscuit production, particularly for crackers for which flour constitutes about 90% of the recipe ingredients, the reduction indicated by the regulations is not achieved. It is concluded that for some commercial processes, the whole-wheat or flour ingredients used will need to contain DON levels lower than those set by legislation to ensure that the final products will still meet statutory limits. Limited results with consignments containing low concentrations of ZON and NIV suggest that their stability and survival are similar to those for DON.     

UTILITY OF CIE TRISTIMULUS SYSTEM IN MEASURING THE OBJECTIVE CRUMB COLOR OF HIGH-FIBER TOAST BREAD FORMULATIONS

The major objectives of this study were to develop high‐fiber toast bread formulations with lighter crumb color and to evaluate the CIE tristimulus system to measure the color of crumb as affected by the addition of various flour mill fractions. The optimized straight‐dough bread making method (AACC method 10‐10B) was used for conducting the baking trials. CIE L* a* b* values of the crumb were measured. Additional color attributes, (whiteness value, redness index (RI), saturation index (SI) and total color difference (ΔE), were calculated from these L* a* b* values. Compared with flour samples, the germ and bran fractions had significantly lower CIE L* a* b* and whiteness values, but higher redness and saturation indices, indicating darker color and hue for the latter. Test bread samples having up to 30% bran and 10% germ, were lighter in crumb color than the control whole wheat flour bread. It was concluded that high‐fiber toast bread, with lighter crumb color than whole wheat flour bread, can be produced by using white flour, and equal proportions of coarse and fine bran at 20%, germ at 5%, and sodium stearoyl‐2‐lactylate at 0.5% levels. The CIE L*a* b* tristimulus system can effectively be utilized for distinguishing crumb color variations in toast bread samples.     

Comparison of baking tests using wholemeal and white wheat flour

Production of whole-grain products can provide more variety in bakery products and might impact positive health effects due to fermentable soluble fibers. To assess technological quality, micro-scale methods using 10 g of white flour are usually carried out, in particular if amount of material or additives is limited. Using wholemeal flour for micro-scale testing might enhance use efficiency of raw material. Up to date, there is no information, whether micro-scale testing of wholemeal flour provides the same information on techno-functionality as classical methods. Two wheat varieties with the same protein concentration but different bread-making performance were used to analyze this aspect. Micro-scale baking test was optimized for wholemeal flour concerning dough consistency and fermentation time. Wholemeal flour reduced loaf volume, but optimization was successful. Although all processing steps of wholemeal baking test were adapted, differences in loaf volume between the two varieties were only present with white flour. Coarse particles in wholemeal flour may be responsible for reduced gas retention. Decreasing particle size of bran material might reduce adverse effects on loaf volume. A micro-scale baking test using wholemeal flour would have several advantages after correct implementation: lower price, less time and material required, direct measurement of quality aspects.     

回添固态发酵麸皮对重组全麦粉品质特性的影响研究

旨在研究回添固态发酵麸皮对所制得的重组全麦粉的品质特性的影响。将固态发酵麸皮和未发酵麸皮回添入小麦粉中制得重组全麦粉,研究重组全麦粉及全麦馒头的品质特性。结果表明:发酵使麸皮的营养成分得到改善,添加固态发酵麸皮的重组全麦粉在粉质特性,糊化特性,热特性和面团黏弹特性上都接近空白小麦粉。未经发酵的麸皮的存在使馒头比容显著(P0.05)降低,质构变差,气孔紧缩,而添加发酵麸皮可以使重组全麦粉制作的馒头的比容显著(P0.05)增大,全麦馒头的质构特性得到明显改善。这说明麸皮经过固态发酵后再回添入小麦粉中能够有效的改善麸皮加入小麦粉带来的负面作用,回添发酵麸皮制得的重组全麦粉品质较好。     

Impact of Guar and Wheat Bran on the Physical and Nutritional Quality of Extruded Breakfast Cereals

Two non‐starch polysaccharides, guar gum and wheat bran, were used at 15% replacement level in a cereal base to produce an extruded breakfast cereal product from both wholemeal and high‐ratio wheat flour mixes. The inclusion of the non‐starch polysaccharides into the flour bases had no significant effect on the expansion ratio of the products. However, the product density and bulk density of the extruded products increased with guar gum and wheat bran addition. The pasting properties of the raw flour and polysaccharide base as well as the extruded products were altered with the incorporation of polysaccharides, with guar gum‐enriched products showing elevated peak and final viscosity readings. This appeared to be related to moisture manipulation and hence the regulation of gelatinisation. In vitro starch hydrolysis of the raw bases and the extruded samples illustrated that the extrusion process significantly increased the availability of carbohydrates for digestion. Additionally, the inclusion of non‐starch polysaccharides in the raw bases significantly reduced the rate and extent of carbohydrate hydrolysis. This potentially glycaemic reducing action was also evident in the extruded products where the incorporation of guar gum at 15% yielded a reduction of starch hydrolysis of 36% in the wholemeal base and 32% in the high‐ratio white wheat flour base.     

INSTRUMENTAL TEXTURE and BAKING QUALITY of HIGH-FIBER TOAST BREAD AS AFFECTED BY ADDED WHEAT MILL FRACTIONS

The effect of bran type, level of addition, particle size, addition of wheat germ, as well as other additives like improvers and dough conditioners, on the instrumental texture and baking quality of high-fiber toast bread (white pan bread) has been investigated. the specific loaf volume decreased significantly (3.45 cc/g) when the bran level was raised to 30%, but at 20% bran addition, the specific loaf volume was superior to that of the control bread. the specific loaf volume of test breads remained higher than the control bread up to a level of 7.5% wheat germ addition. Additives like ascorbic acid (50 ppm) and sodium stearoyl-2-lactylate (0.5%) further improved the baking quality of test bread samples. the objective texture values (measured as compression force, kg) indicated that the test bread with bran addition up to 20% and germ up to 7.5% possessed a softer texture (0.80 kg) than the control bread (1.02 kg). In comparison with control bread, the panelists gave higher sensory scores for all attributes of test bread samples containing up to 20% red coarse bran or up to 30% red fine bran. A similar trend in sensory quality of test samples containing up to 7.5% wheat germ was also observed. High-fiber toast bread made from white flour, equal proportions of coarse and fine bran at 20%, wheat germ at 7.5%, plus sodium stearoyl-2-lactylate at 0.5% levels, was found to possess softer texture and improved sensory quality than the whole wheat flour bread.     

The effect of pea (Pisum sativum L.)‐originated asparaginase on acrylamide formation in certain bread types

The aim of this study was to investigate the effect of pea (Pisum sativum L.)‐originated asparaginase on acrylamide formation in white wheat, wheat bran and whole‐grain wheat breads. Two‐day germinated pea flour was used at 0%, 1%, 3% and 5% levels for each bread type. Acrylamide analysis was performed with liquid chromatography–mass spectrometry. Besides, colour and sensory properties of the breads were evaluated to search out the effects of pea flour substitution on the consumer acceptance. Reduction of acrylamide in white wheat bread was not found significant and addition of pea flour decreased the acceptance. However, it was found that acrylamide level can be reduced by 57% and 68% with addition of 5% pea flour in wheat bran and whole‐grain breads, respectively, without any negative impact on colour and sensory properties.     

Reduction of folic acid during baking and implications for mandatory fortification of bread

A pilot scale study designed to quantify the reduction of folic acid during bread baking in Ireland was undertaken. Flour was fortified with different concentrations of folic acid and used to make four different types of commercial bread. The dispersal of folic acid in flour on a pilot scale was variable but better homogeneity would have been achieved in the final bread due to batch size and thorough mixing of the dough. Generally, the heat degradation of folic acid during baking was between 21.9% and 32.1%. Whilst the percentage degradation of folic acid in white pan loaves, white baguettes and brown soda bread were similar the result in wholemeal bread was found to be significantly higher than in other bread types tested. Taking into account all variables affecting folic acid concentration during baking, a concentration of c. 225 μg 100 g^?1 folic acid would be needed in flour to deliver commercial bread in Ireland with an average folic acid content of 120 μg 100 g^?1 in line with Government requirements.     

Investigation of product quality, sensory profile and ultrastructure of breads made from a range of commercial gluten-free flours compared to their wheat counterparts

Bread is a major staple food consumed daily in all parts of the world. A significant part of the human population cannot tolerate gluten, a storage protein found in wheat, rye and barley, and therefore, products made from alternative cereals are required. During this study, the bread-making potential of seven gluten-free flours, wheat and wholemeal wheat flour was compared. Fermentation potential of the different flours was determined, showing that dough development height of gluten-free and wholemeal wheat samples was lower than for wheat and oat flour. Apart from standard bread quality parameters such as loaf-specific volume and physical crumb texture, also water activity and shelf life have been determined. The shelf life of gluten-free breads was reduced compared to wheat bread. Aroma profiles were evaluated by a trained panel. Wheat, oat and wholemeal wheat breads were liked moderately, while the remaining samples had lower liking scores. Crumb grain characteristics were investigated using image analysis, and microstructure was observed by scanning electron microscopy. Overall, only breads produced from oat flour were of similar quality to wheat bread, and the utilization of buckwheat, rice, maize, quinoa, sorghum and teff flours resulted in breads of inferior quality.     

Optimization of ingredients and baking process for improved wholemeal oat bread quality

Baking technology for tasty bread with high wholemeal oat content and good texture was developed. Bread was baked with a straight baking process using whole grain oat (51/100 g flour) and white wheat (49/100 g four). The effects of gluten and water content, dough mixing time, proofing temperature and time, and baking conditions on bread quality were investigated using response surface methodology with a central composite design. Response variables measured were specific volume, instrumental crumb hardness, and sensory texture, mouthfeel, and flavour. The concentration and molecular weight distribution of β-glucan were analysed both from the flours and the bread. Light microscopy was used to locate β-glucan in the bread. Proofing conditions, gluten, and water content had a major effect on specific volume and hardness of the oat bread. The sensory crumb properties were mainly affected by ingredients, whereas processing conditions exhibited their main effects on crust properties and richness of the crumb flavour. β-glucan content of oat bread was 1.3/100 g bread. The proportion of the highest molecular weight fraction of β-glucan was decreased as compared with the original β-glucan content of oat/wheat flour. A great part of β-glucan in bread was located in the large bran pieces.     

Fate of ochratoxin A in the processing of whole wheat grain during extrusion

Ochratoxin A in cereal foods and some other products is controlled in the European Community by recent legislation with the objective of minimizing consumer exposure to this mycotoxin. Few studies have examined losses during processing. The stability of ochratoxin A during extrusion of contaminated wholemeal wheat flour was examined using pilot scale equipment. Factors examined were temperature, moisture content, screw speed and residence time. Ochratoxin A was partially stable with breakdown, increasing with temperature and moisture content. However, even under the harshest conditions likely to be used in commercial practice, maximum loss was no greater than 40%, with a residence time of about 40 s. The chemical properties of ochratoxin A suggest that breakdown might be affected by changes in pH and that further studies are necessary to investigate this possibility.     

Dough properties and breadmaking qualities of whole waxy wheat flour and effects of additional enzymes

BACKGROUND: Waxy wheat, a new kind of genetically back‐crossed wheat, was applied to make whole bread in this study. Dough properties and bread quality of the whole waxy wheat flour, which was milled from 100% whole grains containing bran and germ, were determined. RESULTS: Whole waxy wheat had lower protein and lipid contents but higher dietary fiber content than whole regular wheat flour. Pasting temperature and viscosity of the whole waxy wheat flour were significantly lower than those of the whole regular wheat. However, the white wheat flour milled from wheat grains with 48% recovery had significantly higher peak viscosity than the whole waxy wheat. Bread made from the whole waxy wheat flour was significantly softer than that from the whole regular wheat flour during storage. However, bread made from whole waxy wheat had significantly lower specific volume than that from the white waxy flour because of the high amount of dietary fiber. Addition of cellulase increased paste viscosity, lowered dough mixing properties and reduced the firmness of the bread. The addition of pentosanase also increased paste viscosity, lowered dough mixing properties, improved loaf volume of bread but increased the firmness of breadcrumbs, while the addition of α‐amylase only increased final viscosity of flour and did not affect dough properties and bread qualities of whole waxy wheat flour. CONCLUSION: As a result, waxy wheat shows superior properties for making whole breads. Additional enzymes are also necessary to improve bread quality and nutritive values of whole waxy bread. Copyright © 2007 Society of Chemical Industry     

不同发酵基质的酸面团对酵母面团体系面包烘焙及老化特性的影响

应用分离自我国传统酸面团的区域特色乳酸菌--旧金山乳杆菌分别发酵小麦粉和小麦麸皮基质制成（小麦/麦麸）酸面团,研究了两种不同发酵基质的酸面团及其添加量对酵母面团体系面包烘焙及老化特性的影响。结果表明：与小麦粉制作的空白组面包相比,小麦酸面团可以明显改善面包的比容和感官品质;添加未发酵麦麸制作的非酸面团麦麸面包品质低于空白组,但引入麦麸酸面团（10%、20%、30%）后面包比容和感官评定得分均高于相对应的非酸面团麦麸面包。小麦酸面团和麦麸酸面团以及小麦麸皮均可以改善面包的老化特性,在相同贮藏期内,酸面团面包和麦麸面包的硬度增加量、水分迁移量和老化焓值都低于空白组,并且添加麦麸酸面团的面包其硬度和老化焓值都低于相对应的非酸面团麦麸面包。     

Distribution of deoxynivalenol and nivalenol in milling fractions from fusarium-infected Japanese wheat cultivars

The fate of the Fusarium mycotoxins deoxynivalenol and nivalenol during the milling of Japanese wheat cultivars artificially infected with Fusarium was investigated. Grain samples with different mycotoxin concentrations were milled using a laboratory-scale test mill to produce eight fractions: three breaking flours (1B, 2B, and 3B), three reduction flours (1M, 2M, and 3M), wheat bran, and wheat shorts. Patent flour for human consumption was made from the 1B, 2B, 1M, and 2M flours, and low-grade flour was made from 3B and 3M flours. The four resulting samples (patent flour, low-grade flour, bran, and shorts) were analyzed for deoxynivalenol and/or nivalenol with an in-house validated analytical method using high-performance liquid chromatography with UV absorbance detection. In samples with different mycotoxin concentrations, the distribution of those toxins differed among the milling fractions. Grains with a lower level of contamination produced bran and shorts samples with a high relative concentration of nivalenol. A high percentage of nivalenol was found in patent flour, followed by bran. Contrary to the less-contaminated sample, the concentration of nivalenol in moderately contaminated grain was high only in the shorts sample. The highest percentage of deoxynivalenol and nivalenol was observed in the patent flour. The results of this study indicate that the distribution of deoxynivalenol and nivalenol in milled Japanese wheat could be influenced by the contamination level of the original grain, and the milling process is not always effective for removal of toxins from wheat grains.