Changes in the content of fructans and arabinoxylans during baking processes of leavened and unleavened breads

Fructans and arabinoxylans (AXs) are prebiotics naturally occurring in cereal grains which have well-known beneficial effects on human health. However, the majority of grains consumed by humans are processed prior to the consumption. The effect of baking on fructan and AX levels has been studied in rye breads, but there is a scarcity of data on the presence of fructans and AXs in wheat breads. Therefore, the aim of this study was to investigate the effect of baking on stability of fructans and total AXs in breads made from both wheat and rye flours. Bread loaves were baked using an automatic bread maker Breville BBM100 (Sydney, Australia). Sugar analysis was performed using high-performance liquid chromatography on a Dionex ICS-3000 unit. This study showed slight loss of total AXs (6–10 %) during preparation processes of leavened, yeast-free and unleavened breads. In contrast, there was 40–60 % degradation in fructan content of leavened, but no significant losses of fructans in unleavened breads. Yeast-free breads had higher contents of both fructans and AXs than leavened breads. Generally, smaller changes in the content of these prebiotics were apparent in wholemeal and rye than in white breads. It seems that differences in the structures of AXs and fructans in cereals, and the presence of yeast play significant role in determining stabilities of these components during baking.     

Effects of baking on protein digestibility of organic spelt products determined by two in vitro digestion methods

Consumption of organic foods is steadily increasing because it is believed to be healthier than conventional foods. This study was designed to investigate protein digestibility of organic spelt bread, biscuit, cookie and muffin in comparison to their corresponding normal wheat products. Three types of fermented bread products namely, yeast leavened, sour and yeast/sour dough were evaluated. Protein digestibility was assessed based on two methods, three-enzyme one-step and two-enzyme two-step digestion in vitro. The one-step digestion method produced results that were comparable with in vivo (rat) methods whereas the two-step digestion method was more reliable in determining differences among the examined wheat products. Organic spelt used in the present study was comparable to common wheat in protein content averaging 15.4 g/100 g dry matter. Slight differences were observed between organic spelt and common wheat products in protein digestibility determined by the two digestion methods. However, significant differences were found among each wheat products. In general, after baking protein digestion was significantly increased. Spelt and common wheat bread products had similar protein digestibility within each type of bread with sour dough breads had the highest protein digestibility. Biscuit, cookie and muffin products possessed lower protein digestibility than breads. In general, variations in protein digestibility due to baking were more noticeable than that found between the two wheats.     

功能性乳酸菌发酵黑豆麦麸酸面团面包的营养及烘焙特性

将黑豆及麦麸作为发酵基质,分别以高产植酸酶的乳酸片球菌(Pediococcus acidilactici)L-19及产β-葡萄糖苷酶的戊糖片球菌(Pediococcus pentosaceus)J-28作为发酵剂制作酸面团面包。探究菌株的生长、酸化及产酶特性,分析体系中植酸与膳食纤维的变化,采用低场核磁共振及磁共振成像技术表征面筋的水合情况,并比较面包面团的物性与微观结构差异,同时对黑豆麦麸酸面团面包的营养及感官品质进行评价。结果表明:在黑豆麦麸基质中,两株乳酸菌生长良好,酸化能力强,两者表现出不同的产酶特性。经发酵后,两种酸面团的植酸降解率分别达到81.08%、59.79%,可溶性膳食纤维含量在总膳食纤维中的占比由发酵前的22.49%分别提高至31.47%、44.15%。黑豆及麦麸干扰面筋水合,不利于形成连续的网络结构,而乳酸菌发酵能够降低黑豆及麦麸对面筋网络的破坏作用。在营养方面,两种酸面团面包的总膳食纤维含量均高于6%,蛋白质含量分别达到13.82%、13.91%,并且具有更优的氨基酸组成模式及更高的体外蛋白消化率。因此,实验中的两株乳酸菌能够有效改善黑豆麦麸酸面团面包的营养及感...     

Nutrient and antinutrient composition of pearl millet grains as affected by milling and baking

Milling of pearl millet grains reflected a change in gross chemical composition. Baking did not cause a significant change in nutrient content of raw pearl millet flour. Milling and heat treatment during chapati (an unleavened bread) making lowered polyphenols and phytic acid and improved the protein digestibility and starch digestibility to a significant extent.     

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.     

Carbohydrate Digestibility and Resistant Starch of Steamed Bread

Sixteen Australian hard and soft wheats and two U.S. hard wheats were milled into flours (break and reduction) for preparation of steamed breads. Chemical composition and rheological properties of the flour were determined. Steamed breads were analyzed for carbohydrate digestibility and resistant starch. There was no relationship between flour type, protein content and specific volume of steamed breads. Carbohydrate digestibility of steamed breads from soft wheat flour was higher than that of breads from hard wheat flour. Reduction flours produced steamed breads with higher carbohydrate digestibility than break flours. Resistant starch was higher in steamed breads from soft wheat flours than in those from hard wheat flours. Reduction flour produced higher resistant starch levels than break flours. Commercial white bread had resistant starch levels similar to those of steamed breads from soft wheat flour and hard wheat reduction flour.     

Composite Flours for Baked Products and Possible Challenges – A Review

This paper is a review of how consumption of bread, other leavened products and unleavened products made from wheat flour has increased rapidly in Nigeria and other developing countries. It examines how this has resulted in large scale importation of wheat and the consequent drain on the nation’s foreign currency earnings. It contains some suggestions on how to reduce the high import bills of wheat by using composite flours or blends of wheatless flours in place of wheat flour for making leavened and unleavened products. Some studies on the quality characteristics of leavened and unleavened products made from composite flours or blends of wheat flours were reviewed. Some possible challenges likely to be encountered in case Nigeria changes from use of wheat flour to composite flours and blends of wheatless flours are also outlined.     

高产植酸酶乳酸菌发酵对黑豆面包蛋白质品质及烘焙特性的影响

从实验室获得1 株高产植酸酶乳酸菌（L-19）并应用于黑豆酸面团面包,同时选用不产植酸酶的乳酸菌（K-12）作为对照。通过分析面包氨基酸组成和营养指标、蛋白质体外消化率、质构特性、超微结构和感官评定,研究其对黑豆酸面团面包蛋白质营养及烘焙学特性的影响。结果表明：添加乳酸菌黑豆酸面团后,面包蛋白营养和烘焙品质都得到了明显改善,其中L-19酸面团面包（L-19SDB）效果最显著。与黑豆面包（BB）相比,L-19SDB植酸含量下降60.68%,蛋白质体外消化率由64.70%升高至73.93%,总氨基酸含量提高73%。同时与其他3 组相比,L-19SDB有更好的氨基酸特征：其必需氨基酸与总氨基酸之比、必需氨基酸指数和生物价均为最高。面包烘焙品质方面,相比黑豆面包BB,L-19SDB和K-12SDB比容分别提高了31.45%和23.59%,硬度降低了68.79%和56.59%。通过ImageJ分析发现,L-19SDB芯囊组织更加均匀,感官评价总体可接受度最高（7.72 分）。     

Quality characteristics improvement of low‐phenylalanine toast bread

This study was designed to prepare and evaluate low‐phenylalanine toast bread made from gliadin‐free wheat flour and hydrocolloids. Wheat protein fraction (gliadin) rich in phenylalanine was extracted using aqueous alcohol solution for the production of low‐phenylalanine wheat flour. Pectin, gum arabic and carboxymethylcellulose (CMC) were used separately to improve the quality of bread at levels of 1, 2 and 3%. Chemical, rheological, organoleptic, baking, staling and microstructure of bread were studied. Phenylalanine content of gliadin‐free bread samples reduced by 43.2% compared with control. Separation of gliadin negatively affected the rheological properties of dough and baking quality of bread, while rheological properties, baking quality and staling were improved upon hydrocolloids addition. Microscopic examination of crumb structure revealed remarkable differences in control and treated breads. It was found that acceptable bread could be produced using gliadin‐free wheat flour with the addition of pectin or CMC up to 2 and 3%, respectively.     

Fate of phytic acid during bread making

The effect of malt addition and yeast concentration on the hydrolysis of phytic acid during different stages of bread making has been reported. There was a considerable hydrolysis of phytic acid with the addition of yeast and malt. In the breads of S-308 and WL-711 wheat varieties, the loss of phytic phosphorus was 6.6. 8,1; 24.6, 23.0 and 26.6, 27.7% in case of nonyeasted, 1.5% and 3% yeasted dough of whole wheat flour (Atta) respectively. However in white bread, the loss of phytic phosphorus was 14.0 and 18.4; 46.2 and 41.5; 51.7 and 49.4%, in non-yeasted, 1.5% and 3% yeasted doughs of S-308 and WL-711 wheat varieties respectively. A significant loss of phytic acid was observed at a yeast level of 1.5 and 3% and with 0.4% malt addition as compared with the control. Most of the phytic acid was hydrolysed during the fermentation and proofing stages in both types of bread samples.     

Sensory and Nutritional Evaluation of Wheat Bread Supplemented with Single Cell Protein from Torula Yeast (Candida utilis)

Experimental breads were made with 2, 4, 6, 8, 10, and 12% torula yeast flour (TYF). Taste panels found that bread fortified with 8% TYF was acceptable. Eight percent TYF raised protein content from 12.42% for all wheat flour bread to 14.22% for supplemented bread. Amino acid analyses indicated a marked increase in amino acid content especially lysine. The protein efficiency ratio (PER) for rats on all-wheat-flour bread was 1.3 1; replacing 8% of the wheat flour with TYF raised PER of supplemented bread to 2.28. Total carcass nitrogen retained by animals fed a diet containing supplemented bread was higher than that retained by rats whose protein was obtained from unsupplemented bread.     

乳酸菌发酵剂对杂粮面团及馒头品质的影响

为研究混合乳酸菌发酵对杂粮面团及馒头品质的影响,将黄豌豆粉、莜麦粉、谷朊粉及燕麦β-葡聚糖（oatmeal β-glucan,OBG）复配成杂粮粉基质,利用直投式混合乳酸菌发酵剂发酵面团制作馒头。探究乳酸菌在面团中的酸化能力,分析杂粮面团中OBG、抗性淀粉（resistant starch,RS）和游离氨基酸含量的变化以及面团的微观结构变化,并对发酵前后的杂粮馒头和小麦粉馒头进行品质及营养特性比较。结果表明,在发酵杂粮面团中乳酸菌酸化能力强,发酵24 h后乳酸和乙酸质量浓度分别达到24.85、8.98 mg/mL。与未发酵的杂粮面团相比,乳酸菌发酵杂粮面团中OBG含量下降32.56%,RS含量上升32.88%,游离氨基酸总量提升至1.46倍,氨基酸组成模式更优,部分蛋白质和纤维素发生降解,面筋网络结构更加紧密且连续。在营养方面,乳酸菌发酵前后的杂粮馒头膳食纤维质量分数均高于6%,蛋白质质量分数分别为40.35%和38.38%,属于高纤维高蛋白食品,显著优于小麦粉馒头。乳酸菌发酵杂粮馒头具有更高的体外蛋白消化率和比容,且乳酸菌发酵杂粮馒头感官评价总评分显著高于未发酵杂粮馒头,整体可接受度...     

Effect of Amino Acids and Peptides on Mixing and Frozen Dough Properties of Wheat Flour

Free amino acids, peptides, and vital wheat gluten were investigated to determine their effect on the mixing and frozen dough baking properties of wheat flour. Addition of 1% cysteine and aspartic acid decreased and glutamic acid, histidine, arginine, and lysine increased the mixing tolerance of flour. Cystine, methionine, tryptophan, and phenylalanine increased but isoleucine, histidine, glycine, arginine, glutamic acid, aspartic acid, and lysine decreased loaf volume of nonfrozen dough breads. However cystine, methionine, tryptophan, and phenylalanine did not increase loaf volume of bread prepared from frozen dough. Vital wheat gluten increased mixing tolerance and bread loaf volume only for the nonfrozen dough. However, wheat gluten hydrolysate, corn, and bonito peptides decreased mixing tolerance after optimum mixing time and were effective in increasing loaf volume for both frozen and nonfrozen dough. As the amount of corn and bonito peptide increased, specific loaf volumes also increased. Addition of 2.5% corn peptide was most effective in increasing loaf volume of frozen dough bread. Crust browning and crumb stickiness increased, whereas crumb softness decreased with addition of peptides. Addition of less than 1% peptide did not adversely affect the aftertaste and off‐flavor of bread. These results suggest that addition of peptides are effective for improving the baking quality of frozen dough, whereas amino acids and gluten have no effect.     

Organoleptic and nutritional evaluation of wheat breads supplemented with soybean and barley flour

Supplementations of soy (full fat and defatted) and barley flours to wheat flours at 5, 10, 15 and 20% levels were carried out to test the effects on organoleptic and nutritional evaluation of the supplemented bread. Additions of 15% barley flour, 10% soy flour (full fat and defatted), 15% barley plus full fat soy flour and 15% barley plus defatted soy flour to wheat flour produced acceptable breads. However, substitution of soy (full fat and defatted) and barley flours to wheat flour separately and in combinations at 20% levels did not produce organoleptically acceptable bread. Various nutritional parameters, such as protein, fat, total lysine, protein digestibility (in vitro), sugars, starch digestibility (in vitro), total and available minerals, antinutrients, dietary fibre and β-glucan were determined in supplemented and control bread. Increasing the level of substitution from 5 to 10% of full fat and defatted soy flour to wheat flour significantly (P<0.05) increased protein (from 12.1 to 13.7 and 12.4 to 13.8%), lysine (from 2.74 to 3.02 and 2.76–3.05 mg/100 g protein) and total calcium (from 70.2 to 81.4 and 71.9–81.8 mg/100 g) contents. However, there was also an increase in phytic acid (238–260 and 233–253 mg/100 g), polyphenol (324–331 and 321–329 mg/100 g) and trypsin inhibitor activity (193–204 and 193–198 TIU/g). When barley flour was substituted separately, and in combinations, with full fat and defatted soy flour up to 15%, this significantly increased the contents of protein, total lysine, dietary fibre and β-glucan. It may be concluded that breads supplemented with barley and defatted soy flour, up to a 15% level, are organoleptically and nutritionally acceptable.     

方便泡馍的研制

通过不同面筋含量的面粉、不同的发酵时间以及死面与发面的不同比例混合等工艺,研究方便泡馍弹性、咀嚼度的最佳效果。最佳实验工艺条件为使用高筋粉,发酵时间60 min,发面与死面1∶4混合。     

Effect of Flour Extraction Rate and Baking on Thiamine and Riboflavin Content and Antioxidant Capacity of Traditional Rye Bread

ABSTRACT:  The effect of rye flour extraction rates and baking on thiamine and riboflavin content, and antioxidant capacity of traditional rye bread were studied and compared with white wheat flour. The content of thiamine was higher (10.9%) in rye dough formulated with dark rye flour (F-100%; extraction rate of 100%) than in rye dough formulated with brown rye flour (F-92%; extraction rate of 92%) that was similar to dough made with wheat flour. The riboflavin content in rye dough made from flour F-100% was also higher (16%) than in dough formulated with flour F-92%, and both provided larger riboflavin content than wheat dough. Baking led to reductions in thiamine of 56% for wheat bread and of 20% for both rye breads; however, this process caused only a 10% decrease in riboflavin for wheat bread and a 30% decrease for rye breads. Trolox equivalent antioxidant capacity, peroxyl radical scavenging capacity, DPPH radical scavenging activity, and Folin–Ciocalteu reducing capacity were higher in rye than in wheat dough and bread. Baking process produced slight changes in antioxidant activity, except for Superoxide Dismutase-like activity where a sharp decrease was observed. Our findings showed that rye breads are an important source of B vitamins and rye breads formulated with dark and brown flours showed better antioxidant properties than wheat bread. Therefore, rye breads should be more widely recommended in human nutrition.     

Use of sourdough fermented wheat germ for enhancing the nutritional, texture and sensory characteristics of the white bread

Lactobacillus plantarum LB1 and Lactobacillus rossiae LB5, isolated from wheat germ and selected based on the kinetics of acidification, were used as starters for the manufacture of sourdough fermented wheat germ. A bread containing sourdough fermented wheat germ as an ingredient (SFWGB) was compared to breads made with (raw wheat germ bread, RWGB) or without (wheat flour bread, WFB) raw wheat germ. The higher concentration of free amino acids mainly differentiated SFWGB from WFB and RWGB. The in vitro protein digestibility of WFB was the highest, even if sourdough fermentation of wheat germ attenuated the difference. Phytase and antioxidant activities of SFWGB were highest. The specific volume and cell-total areas were also the highest for SFWGB. As determined by texture profile analysis, the values of hardness, resilience and fracturability of breads containing wheat germ were lower than those found in WFB. The crust lightness showed a decrease from WFB to SFWGB. As determined by sensory analysis, SFWGB had mainly acid taste and flavour and resulted more salty. Sourdough fermented wheat germ is an ingredient able to enhance nutritional, texture and sensory properties of bread.     

Release of free ferulic acid and changes in antioxidant properties during the wheat and rye bread making process

Changes in the free ferulic acid (FFA) contents and antioxidant properties during bread making processes were determined. Experimental breads were produced from whole meal and white wheat and rye flours, and fermented using either baker’s yeast or sourdough starter. Sourdough fermented bread contained the highest content of FFA. Release of occurred mainly during dough fermentation. A further increase in the ferulic acid content in the bread crumb and a decrease in the crust was observed. Total antioxidant properties of sourdough bread, defined as the sum of lipophilic and hydrophilic compound activities, were significantly (p<0.05) higher than for yeast bread. Sourdough bread contained more methanol soluble phenolic compounds, proteins, tocochromanols, and oxidized products of fatty acids than yeast bread. The equilibrium between the anti- and pro-oxidative compound contents resulted in similar antioxidant properties for bread using both types of fermentation, and to results observed for the flour used for baking.     

Relationship between protein nutritive quality and technological property parameters of wheat flour

The biological value of proteins as well as their importance for the technological quality of wheat flours have been extensively researched. Apart from the other factors, gluten content, structure and functional characteristics are responsible for the flour's technological properties. Functional properties of gluten complex and thus also rheological properties of flour are influenced by the specificity and intensity of interactions among individual protein fractions and likewise of protein interactions with other flour components. Rheological properties of flour and quality parameters of bread are changed to a greater or lesser extent, among other, by addition of free amino acids. The purpose of this work was to explore the relationship between certain essential amino acids of wheat flour and the parameters of flour rheology and bread baking quality.     

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.