Oxidative stability of whole wheat bread during storage

The oxidative stability was examined in whole wheat bread packed in modified atmosphere (nitrogen) using vacuum grade plastic bags and stored for up to 5 weeks. Small, but significant, differences in oxidative stability developed with time for whole wheat bread crumb and crust. The samples were evaluated by direct electron spin resonance (ESR) spectroscopy for detection of free radicals, peroxide value (POV), overall antioxidative capacity using Trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays, and by the content of tocopherols as determined by HPLC. The overall antioxidative capacity was reduced during storage with an accumulation of lipid hydroperoxides peaking after 2-3 weeks of storage. Bread crust was generally found to be more oxidative stable when compared to crumb. Quality of bread with extended shelf life may accordingly be improved minimising oxidation.     

山楂全麦面包的研制

通过在高筋粉中加入全麦粉和山楂粉,并用酵母二次发酵,研制出山楂全麦面包.以感官评分为指标,通过单因素试验和正交试验确定全麦粉、山楂粉、奶粉和食盐的添加量对面包品质的影响.结果表明,山楂全麦面包最佳配方为：全麦粉20％,山楂粉1.6％,奶粉3.5％,食盐0.8％,酵母0.9％,鸡蛋14.3％,水50％,白砂糖9 5％,黄油8.3％和面包改良剂0.47％.由此制得的山楂全麦面包风味独特,富含膳食纤维,具有山楂的营养保健功能.     

Bran characteristics and wheat performance in whole wheat bread

The effect of the composition and physical properties of bran from four wheat samples from different cultivars was determined in whole wheat bread. High specific volume of whole wheat bread was correlated (r² = 0.8275) with strong mechanical properties (low friability) of the bran of wheat cultivars, as determined by sizing (over 425 μm) of bran particles after grinding with a rotor mill. Fibre content and composition of insoluble fibre (hemicellulose, cellulose and lignin) in the bran fraction had a non‐significant (P > 0.05) effect on the performance of wheat cultivars in whole wheat bread. Water absorption of bran was correlated (r² = 0.9532) with its insoluble fibre content. Based on data obtained with white flour, it was not possible to estimate the baking potential of wheat cultivars in whole wheat bread.     

麸皮预处理对全麦面团及面包的影响

本实验分别采用微波、烘烤、常压蒸汽、高压蒸汽对小麦麸皮进行预处理,研究比较了不同预处理方法对全麦面团和面包品质的影响。结果表明：和未处理全麦粉相比,烘烤、常压蒸汽和高压蒸汽处理均使全麦粉的稳定时间提高,其中常压蒸汽效果最显著,提高了4.2 min;同时,这三种处理方式分别使全麦面包的比容增加了6.92%、9.34%、5.19%,硬度分别降低11.81%、21.79%、19.57%,弹性分别提高2.59%、3.06%、1.65%。推测原因是这三种处理方式均显著降低了麸皮中的还原型谷胱甘肽含量,使全麦面团的游离巯基显著减少,二硫键显著增加,其中常压蒸汽和高压蒸汽效果最显著,分别使还原型谷胱甘肽减少了66.77%、69.30%,使游离巯基减少了40.43%、42.77%,使二硫键增加了51.35%、38.63%。综上,采用烘烤、常压蒸汽、高压蒸汽对麸皮预处理,可以通过降低还原型谷胱甘肽含量、提高二硫键含量来提高面团的稳定性,进而改善面包品质,且常压蒸汽处理的改善效果最好。     

Wheat cultivars grown under organic agriculture and the bread making performance of stone-ground whole wheat flour

Stone-ground whole wheat flour is characterised by coarse bran particles and high germ content. Five wheat cultivars were grown over a 3-year period in eight organic farms in Quebec (Eastern Canada) to determine their respective effects on the quality of stone-ground whole wheat bread flour. Grain yield (1.2–3.9 t ha⁻¹), grain protein content (11.3–13.1%, based on 13.5% moisture) and dough mixing stability (6.9–11.1 min) of whole wheat flour varied much according to the farming sites. Whole wheat flour from AC Brio significantly gave the lowest pan bread volume ( P  < 0.05) and best results were obtained with Celtic (whatever the farming site) and site #5 (whatever the cultivar, probably with the exception of AC Brio). Thorough wheat cultivar selection and organic field management would be critical to get whole wheat bread with the highest specific volume.     

高纤维软化麦麸粉在面包中的应用

高纤维软化麦麸是以小麦麸皮为原料,通过新的技术与工艺、配方精制成的粉状产品,将其应用于焙烤制品中,可制得多种多样的高纤维含量制品。本试验仅是其中的一例。     

Analysis of volatile compounds in polished-graded wheat flour bread using headspace sorptive extraction

Flavor compounds are one of the very important factors for the taste of commercial breads, and then the volatile flavor compounds in the present novel polished-wheat-flour breads were determined by headspace sorptive extraction method to develop the baking properties, comparing two baking procedures of straight-common- and sourdough-methods. The polished flours of outermost, middle and innermost fractions, and common flour, CW were used. There were some differences on the compounds and proportions of volatile flavors in all flours between the both methods. The sourdough-method increased the proportions of acids and aldehydes in crust, but decreased those of alcohols and methoxybenzenes identified in the outermost fraction, rather than the straight-common-method. In addition, the sourdough-method lowered the amounts of some compounds related to oxidation products from unsaturated fatty acids and metabolites of species with moldy grains, as compared with the straight-common-method. Furthermore, the amounts of 2-methylpropanol (iso-butanol) and 2-phenylethanol (β-phenyl-ethyl-alcohol) that have been known as favorable flavor compounds on breadmaking distinctly increased in polished flour breads than CW bread, regardless of baking methods. Therefore, the sourdough-method with lactic acid fermentation would be suitable baking procedure for polished flours from the viewpoints of flavor properties. Furthermore, the utilization of sourdough-method for polished flours from middle and innermost fractions might be appropriate to taste and texture of consumers’ request for bread qualities.     

Improvers and functional ingredients in whole wheat bread: A review of their effects on dough properties and bread quality

BackgroundDespite the associated health benefits of whole grains, consumption of whole grain products remains far below recommended levels. Whole wheat bread is often associated with many distinctive attributes such as low loaf volume, firm and gritty texture, dark and rough crust and crumb appearance, bitter flavor, and reduced shelf-life. There is a need to improve its quality and sensory characteristics so as to increase consumer appeal and, ultimately, increase the intake of whole wheat bread. The inclusion of various ingredients improves dough and bread properties.Scope and approachThis review examines the effects of enzymes, emulsifiers, hydrocolloids, and oxidants on the properties of whole wheat bread and dough, with particular attention to effects on loaf volume and hardness. Wheat gluten and other plant materials are also discussed. Gaps in the research into whole wheat bread are identified, and future research needs are recommended.Key findings and conclusionsXylanase reduces the water absorption of whole wheat flour and increases loaf volume and crumb softness by hydrolyzing ararbinoxylans. α-amylase can be beneficial under certain conditions. Phytase may activate endogenous α-amylase. G4-amylase is promising but needs validation by further research on its effect on loaf volume, crumb hardness, and staling. Vital wheat gluten overcomes many of the challenges of whole wheat bread production and is found in the majority of commercial whole wheat breads. Emulsifiers DATEM and SSL can improve the volume, texture and staling profile of whole wheat bread. Several types of improvers are generally needed in combination to provide the greatest improvement to whole wheat dough and bread.     

Selection of phytate-degrading human bifidobacteria and application in whole wheat dough fermentation

Lately, whole wheat products are highly recommended from their healthy properties. However, the presence of phytic acid (InsP(6)) could partly limit their benefits because it decreases the mineral bioavailability due to its chelating properties. The objective of this work was to select strains with high phytate-degrading activity from human feces, and evaluate their suitability for the bread making process. Twenty-three different bifidobacterial strains (13 from infants and 10 from adults) were isolated, belonging to the species Bifidobacterium longum, Bifidobacterium breve and Bifidobacterium catenulatum. The phosphatase and phytase activities of these strains were evaluated as well as their ability to degrade InsP(6) during growth. Then, the fermentative ability of the strain showing the highest phytate-degrading activity (B. longum. BIF307) was determined in whole wheat breadmaking. The use of the selected bifidobacterial strain as starter during whole wheat fermentation resulted in bread with similar technological quality than the control (in absence of bifidobacteria) and crumb with lower levels of inositol phosphates. Therefore, the used of the selected Bifidobacterium strain in whole wheat breadmaking process could provide potential nutritional benefits by decreasing the antinutrient content of the product.     

小麦胚芽粉对馒头品质的影响

研究了小麦胚芽粉加入量对馒头品质的影响。测定不同小麦胚芽粉加入量下制得的馒头的比容、白度、硬度以及感官评分等并观察其变化,结果显示,随着小麦胚芽粉含量的增加,馒头的白度和比容均呈下降趋势,而硬度呈现先平缓后上升的趋势,馒头的感官评分则是先增大后减小,在加入量为6%时所制得的馒头的感官评分最高。     

小麦及其面粉品质对馒头品质的影响

综合分析了小麦与面粉的蛋白质品质、淀粉品质、酶、脂类物质等对馒头品质的影响。     

Bioactive compounds in spelt bread

In this study the milling and baking characteristics of ten strains of spelt wheat (Triticum aestivum ssp. spelta) originated from Polish breeding were shown. Evaluation of the grain included test weight, vitreousness and hardness. White spelt flour with extraction rate of 65–70% was characterized through the analyses of ash, protein, wet gluten and starch contents as well as Farinograph test, Amylograph test and falling number. Most of spelt wheat varieties investigated demonstrated good milling properties and high baking quality. The spelt breads were analyzed for their potential beneficial components, including total phenolic compounds (TPC) and flavonoids (TF), tocopherols (T) and tocotrienols (T3), inositol phosphates (IP) and reduced (GSH) and oxidized (GSSG) glutathione, and then compared to commercial wheat roll based on wheat flour with extraction rate of approximately 70%. The comparison of the bioactive compounds content between spelt breads and wheat showed a similar level of TPC, TF and GSH. The tocopherols and tocotrienols content in spelt bread was about twice lower when compared to wheat roll. Moreover, spelt wheat bread formulated from flour originated from STH 915 strain showed higher content of inositol phosphates when compared to wheat roll and to those breads from flour of STH 975 and STH 974 strains.     

脂肪酶对面包粉品质的影响研究

通过流变学试验、面包烘焙试验,探讨了国产脂肪酶对面包粉品质的影响。试验表明,与对照组相比较,在添加脂肪酶后,面团的流变学性质、面包品质都得到一定改善。由烘焙试验结果可知,脂肪酶对面包制品的内部组织结构,面包芯柔软度等指标都有较好的改良作用。本试验条件下,添加脂肪酶20ppm为最适添加量。     

小麦胚芽面包的研制

为了开发食品资源,改善食品结构,论述了小麦胚芽的营养价值、保健功能和小麦胚芽面包的生产工艺。