Development of functional foods using psyllium husk and wheat bran fractions: Phytic acid contents

Wheat grain is a rich source of phosphorus which is present mostly as phytic acid and is distributed mainly in the bran and germ fractions. Phytic acid has now been recognized as an important phytochemical having antioxidant properties. This study deals with the determination of total as well as phytic phosphorus contents of psyllium (PS), course (CB) and fine wheat bran (FB) enriched pan bread and Arabic flat bread. The concentration of phytic acid in CB, FB, wheat germ, wholegrain wheat flour (WGF), white wheat flour (WWF), and psyllium were found to be 8.86 mg/g, 8.52 mg/g, 6.05 mg/g, 1.74 mg/g, 0.46 mg/g and 0.02 mg/g, respectively. Most of the phosphorus existed as phytic phosphorus (74.7–90.8%) in FB, CB, germ, and WGF as compared to only 42.6% in WWF. The level of phytic phosphorus in pan bread containing 10% CB, 20% FB (both containing with 5% PS) was found to be 0.63 mg/g and 1.53 mg/g respectively, as compared to only 0.34 mg/g in WWF pan bread, and 0.90 mg/g in WGF pan bread. The phytic phosphorus content in Arabic bread made with WGF and 3% psyllium was 1.32 mg/g as compared to only 0.48 mg/g in WWF Arabic flat bread. The results obtained indicate that the level of phytic phosphorus significantly increased in bread formulations containing CB, FB, and WGF, but no change with psyllium addition was observed. Adding these wheat mill fractions, and psyllium will enable bakeries not only to produce fiber-enriched pan bread and Arabic bread but would also benefit consumers to increase their dietary fiber intakes, and health-promoting phytochemicals coming from wheat bran and germ fractions.     

Wheat-yellow pumpkin composite flour: Physico-functional,rheological, antioxidant potential and quality properties of pan and flat bread

The impact of yellow pumpkin powder (YP) substitution (5, 10, and 15%) on wheat flour's physico-functional, pasting, gel texture, and dough rheology was studied. Moreover, the nutritional, organoleptic properties and bioactivity of the composite pan and pita bread were evaluated. An improved water holding capacity was noticed for the blended flour than for control. The pasting parameters were declined significantly (p < 0.05) with increasing YP. Composite flours presented a softer gel texture in the presence of YP. Reduced water absorption, increased dough development time, and lower stability for combined flour dough. The bread with YP depicted increased protein, fat, fiber, and mineral contents, while a reduced volume and specific volume were noticed for pan bread. YP incorporated 5% and did not compromise pan and pita bread's color and overall acceptability. Additionally, composite bread depicted higher total phenolics with enhanced antioxidant activities at the higher substitution of YP.     

Effect of arabinogalactan isolated from Siberian larch on the baking value of soft wheat flour and bread quality

Using additives of arabinogalactan (AG) isolated from Siberian larch, we examined the soft wheat flour quality and quantity of gluten, physical properties of the dough, and quality of finished bread depending on the quantity of the added polysaccharide. In the case of the addition of 1–3% of AG to flour, its content decreases in the final product. An excess amount of AG inhibits yeast growth, which leads to a decrease in bread quality. The optimum addition of AG to flour is 1%, at which the technological properties of flour and dough do not change significantly, but the quality of bread becomes remarkably better; furthermore, arabinogalactan is fully consumed in the course of bread preparation. The use of AG is recommended in the optimum dose for increasing the quality of baked goods.     

粉质质量指数在冬小麦面团品质及烘烤品质中的应用价值研究

为了进一步了解粉质质量指数在小麦面团品质和烘烤品质评价中的作用,对90份冬小麦样品的粉质质量指数(FQN)与揉混仪参数、拉伸仪参数和面包品质参数之间的相关关系进行了研究。结果表明：FQN与揉混仪参数(峰值时间、峰值面积、8min尾高和斜率)有极显著的正相关关系,且以线性相关为主,可以用于评价小麦粉的耐揉性和筋力;FQN与拉伸曲线面积和最大拉伸阻力有较好的相关关系,但与延伸度相关性较小,且以非线性相关为主。因此,FQN不能很好地进行评价面团的拉伸特性;FQN与面包体积、面包评分和面包坚实度有一定的非线性相关关系,FQN可以用作评价面包烘烤品质的参数指标。     

The effect of seaweed composite flour on the textural properties of dough and bread

Seaweeds as food and seaweed-derived food flavors, colors, and nutrients are attracting considerable commercial attention. In the baking industries, hydrocolloids are of increasing importance as bread making improvers, where their use aims to improve dough handling properties, increase the quality of fresh bread, and extend the shelf life of stored bread. Seaweeds contain a significant amount of soluble polysaccharides and have the potential function as a source of dietary fiber. In this study, red seaweed (Kappaphycus alvarezii) powder was incorporated (2–8 %) with wheat flour and used to produce bread. The effect of seaweed composite flour on dough rheological properties and the quality of bread was investigated using various techniques. Farinograph tests were applied to determine the effect of seaweed powder on the rheological properties of wheat flour dough, while texture profile analysis (TPA) was used to measure the textural properties of dough as well as the final product. The results showed that the additions of seaweed powder (2–8 %) increased the water absorption of the dough. TPA results showed that the addition of seaweed powder decreased stickiness properties. Bread produced with seaweed composite flour showed higher values of firmness.     

Cloning and Characterization of a Weissella confusa Dextransucrase and Its Application in High Fibre Baking

Wheat bran offers health benefits as a baking ingredient, but is detrimental to bread textural quality. Dextran production by microbial fermentation improves sourdough bread volume and freshness, but extensive acid production during fermentation may negate this effect. Enzymatic production of dextran in wheat bran was tested to determine if dextran-containing bran could be used in baking without disrupting bread texture. The Weissella confusa VTT E-90392 dextransucrase gene was sequenced and His-tagged dextransucrase Wc392-rDSR was produced in Lactococcus lactis. Purified enzyme was characterized using ¹⁴C-sucrose radioisotope and reducing value-based assays, the former yielding K _m and V _max values of 14.7 mM and 8.2 μmol/(mg∙min), respectively, at the pH optimum of 5.4. The structure and size of in vitro dextran product was similar to dextran produced in vivo. Dextran (8.1% dry weight) was produced in wheat bran in 6 h using Wc392-rDSR. Bran with and without dextran was used in wheat baking at 20% supplementation level. Dextran presence improved bread softness and neutralized bran-induced volume loss, clearly demonstrating the potential of using dextransucrases in bran bioprocessing for use in baking.     

Nutritional and technological assessment of durum wheat-faba bean enriched flours,and sensory quality of developed composite bread

Faba beans are acknowledged as a good source of proteins, minerals, fibers, vitamins and antioxidants. A blending study was undertaken in order to prepare naturally bread from enriched flours with added nutritional value, mainly in terms of Iron and proteins. Enriched flours were prepared with varied levels (25, 30, 35 and 40%) of whole faba bean flour to assess the effects of this substitution on their nutritional and technological properties. Then, whole durum wheat bread (regular) and enriched bread at 40% substitution level (composite bread) were prepared and subjected to sensory evaluation. The substitution level of composite bread was selected on the basis of Iron and proteins contents and technological results of the flour blends. Nutritionally, except for moisture, fibers, fat, zinc and sodium values, significant (p < 0.05) increases were showed in ash, proteins, minerals, total phenolic compounds, condensed tannins, total flavonoids and anti-radical activity values. Technologically, significant (p < 0.05) decreases were recorded for lightness and whiteness index. The gluten strength value revealed a significant (p < 0.05) decrease as whole faba bean flour was added. On the sensory level, the level of substitution (40%) chosen for the manufacture of composite bread resulted in acceptable bread by consumers. Moreover, composite bread was most preferred in aroma as it imparts a feeling of satiety. The observed nutritional improvements could be useful for malnourished people, including those having Iron and proteins deficiencies. Technologically, the observed changes didn’t present limitations since composite bread was accepted by consumers even at 40% substitution level. Besides, the slight preference of composite bread aroma might encourage its consumption by consumers. Also, its promotion of satiety is important for gluten sensitivity sufferers. Our results suggested that 40% is the appropriate ratio to increase, at the same time, Iron and proteins contents of enriched flours as well as their overall nutritional quality. Also it was possible to produce natural composite bread at this level (40%) while maintaining adequate technological and sensory quality.     

Treatment of bran containing bread by baking enzymes; effect on the growth of probiotic bacteria on soluble dietary fiber extract in vitro

Different ways of treating bran by baking enzymes prior to dough making and the baking process were used to increase the amount of water-soluble dietary fiber (DF) in wheat bread with added bran. Soluble DF was extracted from the bread with water and separated from the digestible material with gastrointestinal tract enzymes and by solvent precipitation. The baking enzyme mixtures tested (xylanase and glucanase/cellulase, with and without lipase) increased the amounts of soluble arabinoxylan and protein resistant to digestion. The isolated fiber was used as a growth substrate for 11 probiotic and intestinal Bifidobacterium strains, for commensal strains of Bacteroides fragilis and Escherichia coli, and for potential intestinal pathogenic strains of E. coli O157:H7, Salmonella typhimurium, and Clostridium perfringens. Fermentation analyses indicated that the tested strains had varying capacity to grow in the presence of the extracted fiber. Of the tested probiotic strains B. longum species generally showed the highest ability to utilize the fiber extracts, although the potential pathogens tested also showed an ability to grow on these fiber extracts. In sum, the enzymes used to improve the baking process for high-fiber bread can also be used to produce in situ soluble fiber material, which in turn can exert prebiotic effects on certain potentially beneficial microbes.     

The antimicrobial effect of organic acids, sour dough and nisin against Bacillus subtilis and B. licheniformis isolated from wheat bread

Prevention of growth in wheat bread for more than 6 d of approximately 10⁶ rope-producing Bacillus subtilis spores per gram of dough was achieved by addition of propionic or acetic acids at levels of 0·10% v/w (based on flour weight), or by addition of 15% sour dough fermented with Lactobacillus plantarum C11, Lact. brevis L62, Lact. plantarum ('vege-start 60'), Lact. plantarum (ch 20), Lact. maltaromicus (ch 15), or the commercial sour dough starter culture, Lact. sanfrancisco L99. These cultures resulted in an amount of total titratable acids above 10 in the sour dough and a pH value below 4·8 in the final bread. Bacteriocin-producing lactic acid bacteria added as starter cultures in wheat dough and nisin (Nisaplin) at levels up to 100 p.p.m. g⁻¹ flour had no effect against B. subtilis and B. licheniformis strains, despite the fact that nisin-producing strains of Lactococcus lactis ssp. lactis among 186 strains of lactic acid bacteria had demonstrated inhibitory activity against B. subtilis and B. licheniformis in an agar spot assay.     

Microsatellite-based molecular diversity of bread wheat germplasm and association mapping of wheat resistance to the Russian wheat aphid

Genetic diversity of a set of 71 wheat accessions, including 53 biotype 2 Russian wheat aphid (RWA2)-resistant landraces and 18 RWA2 susceptible accessions, was assessed by examining molecular variation at multiple microsatellite (SSR) loci. Fifty-one wheat SSR primer pairs were used, 81 SSR loci were determined, and 545 SSR alleles were detected. These SSR loci covered all the three genomes, 21 chromosomes, and at least 41 of the 42 chromosome arms. Diversity values averaged over SSR loci were high with mean number of SSR alleles/locus = 6.7, mean Shannon’s index (H) = 1.291, and mean Nei’s gene diversity (He) = 0.609. The three wheat genomes ranked as A > D > B and the homoeologous groups ranked as 7 > 3  > 1 > 2 > 6 > 5 > 4 based on the number of alleles per locus. Xgwm136 on chromosome arm 1AS is the most polymorphic SSR locus with the largest number of observed and effective alleles and the highest H and He. Among all 2485 pairs of wheat accessions, genetic distance (GD) ranged from 0.054 to 1.933 and averaged 0.9832. A dendrogram based on GD matrix showed that all the wheat accessions could be grouped into distinct clusters. Most of the susceptible cultivars (13/18) were clustered into groups that contains all or mostly susceptible accessions. Most of the U.S. cultivars belong to a group that is distinguishable from all the different RWA2 resistant groups. Diversity analysis was also conducted separately for subgroups containing 53 RWA2-resistant accessions and 18 RWA2-susceptible accessions. Association mapping revealed 28 SSR loci significantly associated with leaf chlorosis, and 8 with leaf rolling. New chromosome regions associated with RWA2 resistance were detected, and indicated existence of new RWA resistance genes located on chromosomes of all other homoeologous groups in addition to the groups 1 and 7 in bread wheat. This information is helpful for development of mapping populations for RWA2 resistance genes from different phylogenetic groups, and for wise utilization of the RWA-resistant germplasm in wheat breeding programs.     

收获期对BNS杂交小麦面粉和馒头品质的影响

以BNS低温敏感雄性不育系衍生的3个杂交种为材料,设置5月27日、5月31日和6月4日3个收获期,分析了不同收获时期对小麦面筋含量、面团流变学特性、淀粉糊化特性以及馒头加工品质的影响.结果表明: 收获时期对BNS杂交小麦的面粉白度、蛋白质和干湿面筋含量均有一定影响.最佳收获期因品种而异,百杂1号和百杂2号的最佳收获期为5月27日,百杂3号的最佳收获期为6月4日,此时期收获的小麦面粉品质最好,馒头综合评分和口感也均最好.其中百杂2号于5月27日收获的小麦同时适合馒头和面条的加工.     

Role of lipoxygenase in the determination of wheat grain quality

Analysis of the correlation between endogenous lipoxygenase activity and 15 wheat grain quality parameters in three bread wheat populations has shown that enzyme activity influences the weight of 1000 grains, dough deformation energy, dough tenacity, and mixing properties. The correlations between the enzyme activity and the basic quality parameters are negative at high activity levels. The optimum values of specific lipoxygenase activity at which all quality parameters studied have the maximum values range from 108.5 ± 1.2 to 126.4 ± 1.9. It has been found that the ability of lipoxygenase to strengthen gluten is related to the lowering of dough extensibility.     

Effect of plant oils on quality parameters of Bactrocera tryoni (Froggatt) reared on liquid larval diet

Liquid larval diets have been developed for several tephritid fruit flies including Queensland fruit fly, Bactrocera tryoni (Frogatt) (Q‐fly). In liquid diets, wheat germ oil (WGO) is usually added to improve performance in some quality parameters of reared flies, especially flight ability. However, for some flies, other plant oils may be more readily available, cheaper or produce flies of superior performance. In the present study, four alternative types of plant oils – rice bran, canola, vegetable, and sesame – were incorporated into a fruit fly liquid larval diet to replace the currently used wheat germ oil and their efficacy on the quality parameters of reared Q‐fly was compared to diets containing wheat germ oil or no oil. The quality parameters included: total pupal yield (N), pupal recovery (%), larval duration (days), pupal weight (mg), adult emergence (%), adult fliers (%), rate of fliers (%), sex ratio (%), F₁ egg/female/day and egg hatching (%). There were significant differences among treatments in performance of Q‐fly. Vegetable oil appeared better in terms of total pupal yield, percentage of pupal recovery, percentage of adult emergence, percentage of fliers, mean egg/female/day and % F₁ egg hatch compared with other oil treatments, especially from that of WGO treated diet. The result suggests that WGO can be substituted with rice bran and vegetable oil to improve the liquid larval diet for rearing of B. tryoni, with vegetable oil being the best replacement.     

Treatment of germinated wheat to increase levels of GABA and IP6 catalyzed by endogenous enzymes

We found that the levels of bioactive products from wheat can be increased dramatically by manipulating germination conditions and taking advantage of the activity of endogenous enzymes. The yield of phytic acid (IP(6)) from wheat germinated in the presence of high, controlled levels of dissolved oxygen (188 +/- 28 mg/100 g wheat) was almost three times greater than that from wheat germinated with no supplemental oxygen (74 +/- 10 mg/100 g wheat). The yield of gamma-aminobutyric acid (GABA) from wheat germinated in the presence of uncontrolled levels of dissolved oxygen was 18 +/- 3 times greater than that from nonsupplemented wheat (1 mg/100 g wheat). The concentration of GABA was much greater in wheat germ than in whole wheat, and the yield of GABA from wheat germ processed with supplemental water (163 +/- 7 mg/100 g wheat germ) was notably greater than that from wheat germ processed with no supplemental water (100 +/- 2 mg/100 g wheat germ). In contrast, IP(6) was more concentrated in wheat bran, and the yield of IP(6) from wheat bran processed with supplemental water (3100 +/- 12 mg/100 g wheat bran) was notably higher than that from wheat bran processed with no supplemental water (2420 +/- 13 mg/100 g wheat bran). We conclude that the large amount of GABA extracted from wheat germ is likely due to high glutamate decarboxylase activity and low aminotransferase activity and that the large amount of IP(6) extracted from wheat bran is likely due to high levels of tyrosinase activity. Our findings indicate that bioactive molecules such as GABA and IP(6) can be successfully mass-produced by taking advantage of endogenous enzymatic activities.     

Proteolytic breakdown of gliadin by <Emphasis Type="Italic">Enterococcus faecalis</Emphasis> isolated from Tunisian fermented dough

The aim of this work was to select strains with proteolytic activity on wheat gliadin, among lactic acid bacteria, previously isolated from Tunisian fermented wheat dough. Hydrolysis of gliadin, as sole nitrogen source, in an agar medium was visualized by a clear zone surrounding colonies. The increase in absorbance due to gliadin breakdown was measured spectrophotometrically using O-phthaldialdehyde (OPA) on Gliadin Glucose Broth medium. Fermented liquid dough inoculated with individual selected Enterococcus faecalis, showed a decrease of the gliadin concentration from 45 g/kg to 18 g/kg determined by sandwich ELISA test (R-7001). Only the enterococci strains show an hydrolysis of gliadin proteins. Strains showing proteolytic activity are gaining more and more importance in cereal based fermented foods and may help to reduce gliadin involved in coeliac disease.     

Isolation and properties of Aspergillus niger IBT-90 xylanase for bakery

Xylanase of low molecular weight (K II) was isolated from the fungus Aspergillus niger IBT-90 cultivated in medium with wheat bran. K II was purified by precipitation with ammonium sulphate (20–80% saturation) and gel filtration on Biogel P-10. This enzyme is most active in hydrolysis of birchwood xylan at 50°C and pH 5.5. Xylanase K II has an ability to degrade 1,4-β-bonds and to debranch substrates. It degrades not only xylans but also cellulose, an important factor for its application in bakery. Ag⁺, Fe³⁺ and NBS are strong inhibitors of the enzyme. DTT and Na⁺ activate xylanase K II by 24 and 13%, respectively. Enzyme K II used as additive to flour improves dough properties, increases the volume of wheat–rye and whole meal bread, and increases the porosity of crumb and the moisture of the final product, consequently extending the shelf life of bread.     

Rheological and breadmaking properties of wheat samples infected with<Emphasis Type="Italic">Fusarium spp.</Emphasis>

Rheological and breadmaking properties of untreated and suboptimally stored wheat samples (grain moisture: 20%, temperature: 20°C) and also of wheat which was inoculated withFusarium spp. were investigated. The deoxynivalenol (DON) content of the stored and inoculated wheat samples ranged between 820–12,000 μg/kg. Gluten proteins were isolated with different extraction solutions and the fractions obtained were analysed by means of RP-HPLC. Microextension tests and micro-baking tests were used for the determination of dough properties (maximum resistance (MR) and extensibility (EX)) and bread volume, respectively. In spite of the extremely high DON concentrations of some wheat samples contaminated withFusarium spp. they showed only a slight decrease of the amount of gluten proteins. Extension tests of dough led to a slight decrease of MR, bread volumes stayed almost the same compared with the non-contaminated grain. The contamination of wheat withAspergillus andPenicillium led to a high decrease of gluten proteins, which resulted in an extremely decreased MR of the dough and a very low bread volume.     

Changes in protein quantities of phosphoenolpyruvate carboxylase and Rubisco activase in various wheat genotypes

In early seedlings of wheat genotypes two isoforms of Rubisco activase with molecular weights of 42 and 46 kDa are expressed. Amounts of both isoforms significantly increase in early seedlings of the durum wheat genotype Barakatli-95 exposed to salt stress. But at the beginning of the tillering stage, the changes in quantities of both RCA isoforms are different in durum and bread wheat genotypes subjected to a 3-day drought stress. In the leaves of the early seedlings of the studied wheat genotypes exposed to drought stress quantities of PEPC subunits increase compared to the control but they remain relatively stable in early roots and germinating seeds. However, quantities of its subunits decrease sharply in roots and germinating seeds of early seedlings under the influence of 100 mM NaCl. In flag leaves and ear elements of the Barakatli-95 genotype grown under normal water supply conditions protein quantities of PEPC subunits change differently depending on time. Changes in protein quantities of RCA, PEPC and Rubisco enzymes have been studied comparatively in ear elements and flag leaves after the fourth day of anthesis.     

Analysis and simulation modelling of population dynamics and bioenergetics ofCryptolestes ferrugineus (Coleoptera: Cucujidae) in stored wheat

The consequences of infestation of stored wheat by the rusty grain beetle, Cryptolestes ferrugineus (Stephens) was determined for 222 d at 30°C in 70-1 drums containing wheat at 13.5% moisture content. Temperature, grain moisture, seed damage, germination and weight, dust weight, fat acidity values (FAV), published data on growth, reproduction, survival and cannibalism rates and energy budget were used to develop a computer simulation model to simulate the population dynamics of C. ferrugineus at 30°C. In the insect-free control system, the fungi, Alternaria alternata decreased, Aspergillus glaucus group and Penicillium spp. increased, probably causing a rise in FAV of the grain. In the insect-infested system, C. ferrugineus could only eat the wheat germ of kernels that had a broken bran layer; 35.7% of the wheat germ or 914.6 J per 100 kernels was consumed. Within two generations after initial introduction, C. ferrugineus reached a peak in numbers and biomass polluting the ecosystem with excreta and remains, and accelerating the deteriorative process observed in the insect-free control system by increasing respiration temperature, FAV and reducing grain germination. After 87 d, the insect population declined to low levels. The simulation model provided a close match between the observed and predicted numbers of insect life stages and bioenergetic variables during the insect population growth phase. Simulation trials suggested that cannibalism of larger compared with smaller immature stages would be more wasteful of developmental time and energy, reducing the number of individuals reaching reproductive age, and that density-dependent fecundity was probably not an important regulatory mechanism of C. ferrugineus population dynamics in this study.     

Prebiotic Content of Bread Prepared with Flour from Immature Wheat Grain and Selected Dextran-Producing Lactic Acid Bacteria

In the last few years the need to produce food with added value has fueled the search for new ingredients and health-promoting compounds. In particular, to improve the quality of bakery products with distinct nutritional properties, the identification of new raw materials, appropriate technologies, and specific microbial strains is necessary. In this study, different doughs were prepared, with 10% and 20% flour from immature wheat grain blended with type “0 America” wheat flour. Immature flour was obtained from durum wheat grains harvested 1 to 2 weeks after anthesis. Doughs were obtained by both the straight-dough and sourdough processes. Two selected exopolysaccharide-producing strains of lactic acid bacteria (LAB), Leuconostoc lactis A95 and Lactobacillus curvatus 69B2, were used as starters. Immature flour contained 2.21 g/100 g (dry weight) of fructo-oligosaccharides. Twenty percent immature flour in dough resulted in a shorter leavening time (4.23 ± 0.03 h) than with the control and dough with 10% immature flour. The total titratable acidity of sourdough with 20% immature flour was higher (12.75 ± 0.15 ml 0.1 N NaOH) than in the control and sourdough with 10% immature wheat flour (9.20 ml 0.1 N NaOH). Molecular analysis showed that all samples contained three LAB species identified as L. lactis, L. curvatus, and Pediococcus acidilactici. A larger amount of exopolysaccharide was found in sourdough obtained with 20% immature flour (5.33 ± 0.032 g/kg), positively influencing the exopolysaccharide content of the bread prepared by the sourdough process (1.70 ± 0.03 g/kg). The addition of 20% immature flour also led to a greater presence of fructo-oligosaccharides in the bread (900 mg/100 g dry weight), which improved its nutritional characteristics. While bread volume decreased as the concentration of immature wheat flour increased, its mechanical characteristics (stress at a strain of 30%) were the same in all samples obtained with different percentages of fructo-oligosaccharides. These data support the use of immature wheat grain flour, and exopolysaccaride-producing lactic acid bacteria in formulating functional prebiotic baked goods whose nutritional value can be suitably improved.