Effect of bread baking on the bioavailability of hydrogen-reduced iron powder added to unenriched refined wheat flour

Elemental iron powders are widely used to fortify flour and other cereal products. Our objective was to test the hypothesis that baking enhances the bioavailability of elemental iron powders by oxidizing Fe(0) to Fe(2+) or Fe(3+). An in vitro digestion/Caco-2 cell culture model and a piglet model were used to measure bioavailability. Bread flour, either unfortified or fortified with hydrogen-reduced (HR) iron powder or FeSO(4) (300 mg Fe/kg flour), was baked into bread. For the in vitro studies, bread samples were treated with pepsin at pH 2, 3, 4, 5, 6, or 7 and subsequently incubated with pancreatic enzymes at pH 7 in a chamber positioned above monolayers of cultured Caco-2 cells. Ferritin formation in the cells was used as an index of iron bioavailability. Ferritin formation in cells fed HR Fe bread was similar to cells fed FeSO(4) bread when the peptic digestion was conducted at a pH 2 but lower when the peptic phase was conducted at pH 3, 4, 5, 6, or 7 (P < 0.05). Pig diets containing 35% dried bread were prepared and fed to cross-bred (Hampshire x Landrace x Yorkshire) anemic pigs in two studies. The rate of increase in hemoglobin Fe over the feeding period was used to calculate relative biological value (RBV), an index of iron bioavailability. In the first pig study, RBV of HR Fe added to flour prior to baking was 47.9% when compared to FeSO(4) fortified flour (P < 0.05). In the second pig study, a third treatment consisting of unfortified bread with HR iron added during diet mixing (after bread baking) was included. RBVs of the HR Fe diet (Fe added after baking) and HR Fe diet (Fe added before baking) were 40.1% and 53.5%, respectively, compared to the FeSO(4) diet. Differences in RBV between the HR Fe (before and after baking) and FeSO(4) (before baking) treatment groups were significant, but the difference between the before and after HR treatment groups was not significant. We conclude that bread baking does not enhance the bioavailability of elemental iron powders.     

荞麦粉—小麦粉混粉流变学特性研究

以小麦粉为对照，对荞麦全粉、荞麦心粉、荞麦麸粉的理化特性进行了分析，参照国际标准分析方法，系统分析了荞麦粉-小麦粉混粉的粉质特性、拉伸特性以及糊化粘度特性等流变学特性。试验结果表明，与小麦粉相比，荞麦粉的粘度很高，β-淀粉酶活性很低，降落值大于1000 s。荞麦籽粒中各营养成分分布不平衡，荞麦麸粉的营养价值高。小麦粉中加入荞麦粉，当荞麦粉比例不超过30%时，混粉尚有较好的加工特性。与荞麦全粉相比，荞麦心粉具有较好的加工性能。     

Semicarbazide formation in flour and bread

Azodicarbonamide, an approved food additive, is commonly used as a flour additive and dough conditioner in the United States and Canada. A number of researchers have clearly established a link between the use of azodicarbonamide and semicarbazide contamination in commercial bread products. However, all of these studies have primarily focused on the final baked product and have not extensively investigated the processing and conditions that affect the final semicarbazide levels. In this study, a previously developed method for measuring free semicarbazide in bread was applied to dough samples during the mixing and kneading process. Additionally, flour and bread samples were spiked with biurea or azodicarbonamide to help elucidate semicarbazide formation pathways. The results showed that semicarbazide was not formed as a byproduct of azodicarbonamide decomposition to biurea, which occurs upon the addition of water. Indeed, semicarbazide was not detected after room temperature or elevated temperature dough maturation, but only after baking. It was concluded that although azodicarbonamide is the initial starting material, semicarbazide formation in bread occurs through a stable intermediate, biurea.     

Effect of nitrogen fertilizer levels and irrigation on quality characteristics in bread wheat (Triticum aestivum L.)

In order to evaluate irrigation regimes and nitrogen fertilization on quality characteristics of wheat cultivars, a field experiment was carried out using split-plot factorial design based on randomized complete block design with three replications in Quchan, Iran (2010–2012). Main plots were assigned with four irrigation regimes; I1, 90 mm; I2, 130 mm; I3, 170 mm based on evaporation from a class A pan; and I4, water deficit stress during post-anthesis stage; sub-plots were assigned with four levels of nitrogen (N1, 0; N2, 70; N3, 140; and N4, 210 kg ha^?1); and three wheat cultivars (V1, Mihan; V2, C-87-6; and V3, C-87-11) were used as factorial. The results showed that nitrogen fertilization increased some quality characteristics. Under water deficit (I4), gluten index, grain protein content, grain yield, and sedimentation volume decreased. Significant interactions between irrigation regimes and both nitrogen levels and cultivars were observed.     

Phytochemical composition, anti-inflammatory, and antiproliferative activity of whole wheat flour

Whole wheat flour from five wheat cultivars was evaluated for phenolic, carotenoid, and tocopherol compositions as well as anti-inflammatory and antiproliferative activities against HT-29 cells. The total ferulic acid content ranged from 452 to 731 μg/g among the five cultivars and was primarily present in the insoluble-bound form. Lutein was the only carotenoid detected and ranged from 1.5 to 4.0 μg/g, and α-tocopherol levels ranged from 12 to 61 μg/g. Extracts of four cultivars demonstrated significant anti-inflammatory activity, measured as inhibition of interleukin-1β (IL-1β) mRNA expression; however, none of the extracts inhibited tumor necrosis factor-α (TNF-α) mRNA expression, a second indicator of anti-inflammatory activity. Proliferation of HT-29 adenocarcinoma cells was inhibited by extracts from all cultivars at the dose of 100 mg botanical equivalent/mL. The cultivar WestBred 936 had the greatest antiproliferative activity at lower concentrations (20 and 50 mg botanical equivalent/mL), had the greatest anti-inflammatory effect against IL-1β, and also had the highest levels of ferulic acid and α-tocopherol. This research shows that whole wheat flours of these five cultivars varied significantly in their contents of phenolics, carotenoids, and α-tocopherol as well as in their anti-inflammatory and antiproliferative potentials, suggesting the possibility that wheat varieties can be selected based on potential health benefits.     

Effect of fungicide treatment on the quality of wheat flour and breadmaking

Fungicides are applied to crop plants to ensure disease protection and improve growth. To assess the effects of five commercial foliar and spike fungicides in four different combinations on wheat (Triticum aestivum L.), various quality parameters and flour processing properties, including baking quality, were determined. Three commonly used wheat cultivars with different quality classes (E, B, and C) were tested. Falling number, crude protein content, water absorption ability, protease activity, viscosity, and the free amino acid content were mainly lower in the fungicide-treated grains than in the untreated grains. None of the fungicides caused any significant changes in the wet gluten content, dough properties, the mono- and oligosaccharide content, or the breadmaking quality. In general, the commercial fungicide treatments did not cause any statistically significant differences between the treated and the untreated samples with respect to the quality parameters analyzed, although there were indeed significant differences between the three cultivars themselves.     

Shift of grain protein composition in bread wheat under summer drought events

Climate change bears the risk of more frequent drought stress in the northern hemisphere with more frequent early summer drought events affecting main grain crops. Winter wheat (Triticum aestivum L.) is susceptible for such drought events at the flowering and grain filling stages. After drought, the grain yield decrease of three hybrids was about 20% lower compared to three wheat lines analyzed. Wheat grain proteins are classified into four main components such as albumin and globulin, gliadin, and glutenin. The latter two are closely related to the baking quality of flour and might be affected by drought. However, detailed knowledge about the influence of drought on the synthesis of specific storage protein fractions is scarce. By analyzing the grain protein fractions by means of SDS‐PAGE technique, we detected an increase in grain protein content as well as in HMW and some LMW glutenin sub‐fractions. The glutenin fraction seems to be most variable in gene expression under different environmental scenarios such as drought. However, the protein yield as well as the grain yield may be strongly decreased, which might be not acceptable in practice.     

钾肥用量对面包强筋小麦产量和品质的影响

采用田间试验研究不同钾肥用量对龙 94 - 40 83面包强筋小麦产量与品质的影响 ,结果表明施钾明显增加小麦产量 ,K2 O用量 5 2 .5～ 82 .5 kg/ hm2 比较适宜。施钾能明显改善小麦品质 ,小麦粗蛋白和湿面筋含量、沉降值、稳定时间、最大阻力、延伸性、拉伸面积、面包体积和面包评分均有不同程度的提高 ,尤其是对稳定时间的延长效果更为明显。     

不同品种小麦粉的粉质特性对速冻熟制面条品质的影响

为研究不同品种小麦粉与速冻熟制面条质构特性之间的关系,选取30种小麦制粉,用FOSS定氮仪、快速黏度仪、粉质仪和拉伸仪等测定面粉品质指标,制作速冻熟制面条,用质构仪测定质构特性。采用描述性统计、主成分和聚类分析方法对30种小麦面粉和速冻熟制面条的质构关系进行了分析。结果表明:不同品种小麦粉的湿面筋、糊化温度、弱化度、粉质质量指数与硬度呈极显著相关(P0.01);蛋白质、湿面筋、总淀粉含量、最终黏度、回生值、糊化温度、粉质吸水率、粉质曲线稳定时间、面团形成时间、弱化度、粉质质量指数、拉伸曲线面积、拉伸阻力、最大拉伸阻力与剪切力呈极显著相关(P0.01);小麦粉的粉质特性,除衰减值、峰值时间和延伸度外,均与拉伸力呈极显著相关(P0.01)。根据方差贡献率提取出可以反映原变量84.023%信息的5个因子,因子1主要反映面粉的粉质拉伸特性,因子2反映小麦粉糊化特性,因子3反映蛋白质特性,因子4和因子5共同反映小麦粉的淀粉特性。这些性状在小麦粉的评价方面起着重要作用,在加工中要注重对它们的选择。聚类分析将30种小麦粉分为4类,结果表明,不能仅凭小麦粉的指标数据和质构数据来选择制作速冻熟制面条的原料,还需考虑到感官评价的影响。该结论可为小麦粉在速冻熟制面条加工应用方面提供一定的理论参考。     

Effect of cyclodextrin glycosyl transferase [corrected] on dough rheology and bread quality from rice flour

Gluten-free breads are usually characterized by deficient quality characteristics as compared to wheat breads. Problems related to volume and crumb texture are associated with gluten-free breads even when rice flour is used, which seems to be the best raw material for this type of bread. The potential use of cyclodextrin glycosyl transferase (CGTase) as a rice bread improver is presented. The effect of CGTase addition to rice flour on dough rheology and bread quality was investigated. In addition, an experimental design was developed to optimize the levels of CGTase, hydroxypropylmethylcellulose (HPMC), and oil. The addition of CGTase produced a reduction in the dough consistency and also in the elastic modulus. With regard to the rice bread quality, better specific volume, shape index, and crumb texture were obtained. The amount of cyclodextrins in the bread crumb was quantified to explain the action of this enzyme. The data indicate that the improving effect of the CGTase results from a combination of its hydrolyzing and cyclizing activities, the latter being responsible for the release of cyclodextrins, which have the ability to form complexes with lipids and proteins.     

Variation and genetic diversity for gliadins in Spanish spelt wheat accessions

Gliadin composition has been analysed in 403 accessions of spelt wheat (Triticum aestivum ssp. spelta); 61 different patterns were found for the -gliadins, 44 for the -gliadins, 19 for the -gliadins and 15 for the -gliadins. A subset of 333 accessions belonging to fifty populations from Asturias, North of Spain, showed high levels of genetic variation (A = 3.89, P = 0.88, Ne = 3.35 and He = 0.553), indicating that 82.5% of the genetic variation was within populations, and only 18.5% among populations. Thirty-five of these populations presented more of five accessions, in this new subset the values of genetic variation were higher that those of fifty populations (A = 4.49, P = 0.91, Ne = 3.80 and He = 0.595). The genetic variation within populations was 59.7% of the total, and 40.3% among populations, which could be associated to fixation effects of some alleles by genetic drift.     

Effect of root morphological traits on zinc efficiency in Iranian bread wheat genotypes

Zinc (Zn) has a vast number of functions in plant metabolism, the lack of which had dramatic effects on growth and yield of plants. Plants have morphological and biochemical responses to enhance mineral solubility in the soil and facilitate uptake, such as root plasticity, secretion processes and symbioses. Root architecture modification is an important plant response to nutrient availability. The aim of this study was to identify root morphological reactions to Zn efficiency in Iranian bread wheat genotypes. Soil and solution cultures were used to survey Zn efficiency. In soil culture, six and seven genotypes with high and low Zn contents were selected among 110 Iranian bread wheat genotypes, respectively. The solution culture experiments were set up in a completely randomized block design and plants fed with Johnson’s grass solution. All traits were assessed at 30 and 60 DAPs (days after planting). Our results showed a significant difference between two groups of efficient and inefficient genotypes only at 60 DAP, and Zn-efficient genotypes showed 1.63-, 1.50-, 1.69- and 1.92-fold increases in root diameter, surface area density, shoot and root dry weight, respectively, compared to inefficient genotypes. In contrast, Zn-inefficient genotypes had 1.20- and 2.62-fold more root length and fineness, respectively, than efficient genotypes. The positive significant correlations were observed between shoot and Zn uptake as well as root dry weight and Zn uptake at both stages. Furthermore, shoot and root dry weight showed a significant correlation with root fineness, diameter and surface area density at both stages. The path analysis showed indirect effects on Zn uptake through root traits. Our results showed that roots have a major role in Zn efficiency. Therefore, the better growth and greater Zn uptake in efficient genotypes, compared to inefficient ones, can be attributed to greater root diameter and surface area density, and lower root fineness in these genotypes.     

热辅助超高压对复合甜面酱品质特性的影响

该文分别从流变、色差、风味及脂肪酸组成等方面展开试验,旨在研究热辅助超高压技术对甜面酱感官品质等品质特性的影响。结果表明,复合甜面酱经热辅助超高压处理后,黏度降低,并随着压力增加,黏度逐渐下降。经300 MPa和400 MPa处理后的样品的黏度变化小于500 MPa处理的样品。经过加压处理后,甜面酱的色差值(ΔE)发生显著变化,棕色指数(browning index,BI)下降,但亮度(L*)和红绿色度值(a*)无显著变化(P0.05)。复合甜面酱中的挥发性风味物质以醛类、酯类为主,酯类含量在高压处理后减少。此外,400 MPa的热辅助超高压处理并没有对脂肪酸的组成和含量造成较大的影响。由此得知,400 MPa、45℃、10 min的热辅助超高压处理可以较好地保护复合甜面酱质地、色泽、风味等方面的品质。为热辅助超高压技术对复合调味酱的进一步研究及工业化生产提供了理论依据。     

Intra- and interpopulation diversity for HMW glutenin subunits in Spanish spelt wheat

The diversity of HMW glutenin subunits in spelt wheat, Triticum aestivum ssp. spelta, was studied electrophoretically in 333 accessions grouped in 50 populations originally collected from Asturias, North of Spain, in 1939. The inter- and intra-population distribution of HMW glutenin alleles at the Glu-A1, Glu-B1 and Glu-D1 loci were investigated. The results show that the genetic variation in HMW glutenin subunits is mainly present within populations, being the variation between populations only 21%. The materials analysed showed a wide polymorphism for the HMW glutenin subunits, although some allelic variants were clearly dominant. This suggests the possibility of a loss of variability before the collection that could have increased with the subsequent reduction of the cultivation area of this species in this Spanish region.     

Use of near-isogenic wheat lines to determine the glutenin composition and functionality requirements for flour tortillas

In wheat ( Triticum aestivum L), the synthesis of high molecular weight (HMW) glutenins (GS) is controlled by three heterologous genetic loci present on the long arms of group 1 wheat chromosomes. The loci Glu-A1, Glu-B1, and Glu-D1 and their allelic variants play important roles in the functional properties of wheat flour. This study focused on understanding the functionality of these protein subunits on tortilla quality. Near-isogenic wheat lines in which one or more of these loci were absent or deleted were used. Tortillas were prepared from each deletion line and the parent lines. The elimination of certain HMW-GS alleles alter distinct but critical aspects of tortilla quality such as diameter, shelf stability, and overall quality. Two deletion lines possessing HMW-GS 17 + 18 at Glu-B1 and deletions in Glu-A1 and Glu-D1 had significantly larger tortilla diameters, yet tortilla shelf life was compromised or unchanged from the parent lines used to develop the deletion lines or the commercial tortilla flour used as a control. Alternatively, a deletion line possessing Glu-A1 and Glu-D1 (HMW-GS 1, 5 + 10) and a deletion in Glu-B1 also significantly improved tortilla diameters. Whereas the increase in diameter was less than the line possessing only HMW-GS 17 + 18 at Glu-B1, the stability of the tortillas were, however, maintained and improved as compared to the parent lines containing a full compliment of HMW-GS. Thus, the presence of subunits 5 + 10 at Glu-D1 alone or in combination with subunit 1 at Glu-A1 appears to provide a compromise of improvement in dough extensibility for improved tortilla diameters while also providing sufficient gluten strength to maintain ideal shelf stability.     

长期定位条件下氮肥对小麦面粉及面条品质的影响

为了探索河北省优质专用面条小麦的适宜氮肥用量。在3年定位试验的基础上,于2019—2021年采用施氮量×品种二因子裂区设计方法,施氮量为主区(氮用量分别为0、60、120、180、240和300 kg/hm²),品种为副区(冀麦738和济麦22),研究了施氮量对小麦面粉品质、淀粉糊化特性以及面条性状等指标的影响。结果表明,氮肥可显著提高小麦产量、面粉及面条品质。面条总评分与面粉的蛋白质含量、湿面筋含量、沉淀指数、吸水率、稳定时间、拉伸面积、延展度均呈显著或极显著正相关,施氮量达180 kg/hm²以上时,面粉大多品质指标得到改善,面团弹性较好。面条总评分与面粉糊化特性指标均呈正相关,但相关性均未达显著水平,低谷黏度、最终黏度和回升值冀麦738为施氮量120 kg/hm²左右表现较优,而济麦22对氮肥不敏感,同样峰值黏度和糊化温度对氮肥也不敏感。面条总评分与面条质构指标最大拉力、拉伸面积和拉伸距离均呈显著或极显著正相关,与生熟面片的亮度L 值和黄度b 值相关性不显著,冀麦738施氮量大多在180～240 kg/hm²之间、济麦22在180 kg/hm²条件下面条质构指标及亮度较佳。面条总评分与面团的最大拉伸阻力呈负相关,因此中筋小麦品种济麦22更适宜做面条,而中强筋品种冀麦738面粉品质较高,但筋力过大,造成面条感官变差,评分降低。综合考虑小麦产量、面团品质、淀粉糊化特性、面条性状等指标,优质面条小麦较适宜的施氮量为180 kg/hm²左右,此研究结果为河北省优质小麦高产提质提供支撑。     

Proteomic analysis of wheat flour allergens

Wheat can cause severe IgE-mediated systematic reactions, but knowledge on relevant wheat allergens at the molecular level is scanty. The aim of the present study was to achieve a more detailed and comprehensive characterization of the wheat allergens involved in food allergy to wheat using proteomic strategies, referred to as "allergenomics". Whole flour proteins were separated by two-dimensional gel electrophoresis with isoelectric focusing and lithium dodecyl sulfate-polyacrylamide gel electrophoresis. Then, IgE-binding proteins were detected by immunoblotting with sera of patients with a food allergy to wheat. After tryptic digestion, the peptides of IgE-binding proteins were analyzed by matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry. In this study, we identified four previously reported wheat allergens or their sequentially homologous proteins [serpin, alpha-amylase inhibitor, gamma-gliadin, and low molecular weight (LMW) glutenin] by a database search. As a result of the high resolution of two-dimensional gel electrophoresis, nine subunits of LMW glutenins were identified as the most predominant IgE-binding antigens. The two-dimensional allergen map can be beneficial in many ways. It could be used, for example, for precise diagnosis of wheat-allergic patients and assessment of wheat allergens in food. Additionally, we compared allergenomics to conventional biochemical methods and evaluated the usefulness of a proteomic strategy for identifying putative allergens to wheat allergy.     

Effect of flour minor components on bubble growth in bread dough during proofing assessed by magnetic resonance imaging

Fermentation of dough made from standard flour for French breadmaking was followed by nuclear magnetic resonance imaging at 9.4 T. The growth of bubbles (size > 117 microm) was observed for dough density between 0.8 and 0.22 g cm(-3). Cellular structure was assessed by digital image analysis, leading to the definition of fineness and rate of bubble growth. Influence of composition was studied through fractionation by extraction of soluble fractions (6% db), by defatting (< 1% db) and by puroindolines (Pin) addition (< or = 0.1%). Addition of the soluble fraction increased the dough specific volume and bubble growth rate but decreased fineness, whereas defatting and Pin addition only increased fineness. The role of molecular components of each fraction could be related to dough elongational properties. A final comparison with baking results confirmed that the crumb cellular structure was largely defined after fermentation.