首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
Barley flour (BF) from whole naked grain and two (1→3,1→4)-β-glucan-enriched fractions, a sieved fraction (SF) and a water-extracted fraction (WF), were produced and mixed with bread wheat flour (BW), for bread-making quality evaluation. Bread was baked in a pilot plant and analysed for sensory properties, proximate composition and (1→3,1→4)-β-glucan content. Four kinds of bread were produced from different mixtures of barley ingredients and bread wheat flour: a 100% BW ((1→3,1→4)-β-glucan content: total, 0·1%; soluble, 0·1%); a 50% BW and 50% BF (2·4%; 2·0%); a 50% BW and 50% SF (4·2%; 2·8%); an 80% BW and 20% WF (6·3%; 5·7%). Eight adults were fed test meals of each of the four breads, containing the same amount (50 g) of available carbohydrate, and glycemic indices calculated from finger-prick capillary blood samples. A linear decrease in glycemic index was found for increasing (1→3,1→4)-β-glucan content. The 20% WF bread had a 28% lower glycemic index than the plain BW and also showed the best scores for sensory attributes. This research confirms the effectiveness of viscous (1→3,1→4)-β-glucan in reducing postprandial blood glucose levels, even in foods with a high glycemic index. The enrichment technique, and water extraction/freeze-drying technique, could enable the use of barley as a source of a high-value fibre for reducing the glycemic index of traditional wheat-based foods such as bread, without negatively affecting their sensory characteristics.  相似文献   

2.
Physico-chemical properties of bread baked by partially replacing normal wheat (Triticum aestivum L.) flour (15, 30, and 45%) with two hard waxy wheat flours were investigated. Substitution with waxy wheat flour resulted in higher loaf volume and softer loaves. However, substitution at >30% resulted in excessive post-bake shrinkage and a ‘key-hole’ shape with an open crumb structure. Bread crumb microstructure indicated a loss of starch granule rigidity and fusing of starch granules. The cells in the interior of the bread did not become gas-continuous and as a result, shrunk as the loaf cooled. Soluble starch content was significantly higher in bread crumb containing waxy wheat flour than in control bread. Debranching studies indicated that the soluble starch in bread made with 30-45% hard waxy wheat flour was mostly amylopectin. Incorporation of waxy wheat flour resulted in softer bread immediately after baking but did not retard staling upon storage.  相似文献   

3.
The objective of the present study was to evaluate the effect of the bread supplemented with whole amaranth flour (0, 20 and 40%) on iron bioavailability using Caco-2 cells model. The phytate and lower myo-inositol phosphates content in in vitro bread digests were measured by high pressure liquid chromatography. The breads made with amaranth showed significant increase of soluble phytates levels (up to 1.20 μmol/g in dry matter for the 40% of substitution) in comparison with controls, which have not detectable values. A negative correlation among phytate and Fe availability was found when increased levels of amaranth. Ferritin concentration was found 2.7- and 2.0-fold higher (P < 0.05) in cultures exposed to 20% and 40% of amaranth formulated bread samples, respectively, compared to control bread. The soluble phytate/Fe molar ratio explained the whole amaranth flour-mediated inhibitory effect associated to the limitation of available Fe; however, the use up to 20% of amaranth in bread formulation appears as a promising strategy to improve the nutritional value of bread, as indicated by the ferritin concentrations quantified in cell cultures. Higher proportion of amaranth flour increased Fe concentration although there was not detected any increase in Fe uptake.  相似文献   

4.
The purpose of this study was to determine the chemical composition and antioxidant capacity of blue maize (BM) (Zea mays L.) flour and to investigate the effects of polyphenol-containing extracts and BM wholegrain flour on starch digestion under uncooked and cooked conditions; commercial white maize flour was used as control. Total phenolic content in BM flour (BMF) (164 ± 14 mg gallic acid/g of dry matter) was higher than white maize (127 ± 7 mg gallic acid/g of dry matter), and the presence of anthocyanins (2.0 ± 0.5 mg cyanidin 3-glucoside/100 g) was detected. Also, an important scavenging activity against ABTS (2,2’-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and ferric reducing power (FRAP) was determined. Extracts of BMF reduced amylase activity (>90% of inhibition). BMF showed higher slowly digestible and resistant starch contents, thus exhibiting lower predicted glycemic index than white maize. Total anthocyanins (r = −0.89 and r = −0.79, p<0.05), antioxidant capacity (r = −0.86 and r = −0.96, p<0.05), total starch (r = 0.99 and 0.92, p<0.05) and resistant starch content (r = −0.99 and r = −0.92, p<0.05) were correlated with pGI for uncooked and cooked flours, respectively. These results indicate the potential use of BMF and its phenolic-rich extract as functional ingredients to develop antioxidant and indigestible carbohydrate-rich foods with potential health benefits.  相似文献   

5.
Increases in the proportion of amylose in the starch of wheat grains result in higher levels of resistant starch, a fermentable dietary fiber associated with human health benefits. The objective of this study was to assess the effect of combined mutations in five STARCH BRANCHING ENZYME II (SBEII) genes on starch composition, grain yield and bread-making quality in two hexaploid wheat varieties. Significantly higher amylose (∼60%) and resistant starch content (10-fold) was detected in the SBEII mutants than in the wild-type controls. Mutant lines showed a significant decrease in total starch (6%), kernel weight (3%) and total grain yield (6%). Effects of the mutations in bread-making quality included increases in grain hardness, starch damage, water absorption and flour protein content; and reductions in flour extraction, farinograph development and stability times, starch viscosity, and loaf volume. Several traits showed significant interactions between genotypes, varieties, and environments, suggesting that some of the negative impacts of the combined SBEII mutations can be ameliorated by adequate selection of genetic background and growing location. The deployment of wheat varieties with increased resistant starch will likely require economic incentives to compensate growers and millers for the significant reductions detected in grain and flour yields.  相似文献   

6.
This work aimed to study the in vitro colonic fermentation profile of unavailable carbohydrates of two different kinds of unripe banana flour and to evaluate their postprandial glycemic responses. The unripe banana mass (UBM), obtained from the cooked pulp of unripe bananas (Musa acuminata, Nanicão variety), and the unripe banana starch (UBS), obtained from isolated starch of unripe banana, plantain type (Musa paradisiaca) in natura, were studied. The fermentability of the flours was evaluated by different parameters, using rat inoculum, as well as the glycemic response produced after the ingestion by healthy volunteers. The flours presented high concentration of unavailable carbohydrates, which varied in the content of resistant starch, dietary fiber and indigestible fraction (IF). The in vitro colonic fermentation of the flours was high, 98% for the UBS and 75% for the UBM when expressed by the total amount of SCFA such as acetate, butyrate and propionate in relation to lactulose. The increase in the area under the glycemic curve after ingestion of the flours was 90% lower for the UBS and 40% lower for the UBM than the increase produced after bread intake. These characteristics highlight the potential of UBM and UBS as functional ingredients. However, in vivo studies are necessary in order to evaluate the possible benefic effects of the fermentation on intestinal health.  相似文献   

7.
Protein isolate from green gram (Phaseolus aureus) was prepared and the chemical composition was determined. It contained 64.04% protein, 1.8% total lipids, 27.64% total carbohydrates, 1.68% crude fibre and 4.84% ash. Iron, calcium, magnesium, copper, zinc, potassium and sodium were determined. The limiting amino acid in the protein isolate was lysine. In vitro digestibility pepsin followed the pancretion was the highest and the lowest was the digestion by pepsin alone. Water absorption, oil absorption, emulsion capacity and nitrogen solubility index (NSI) of the protein isolate were 2.26g/g, 1.24g/g, 31.4g/g and 6.8g/g, respectively. For comparison the same functional properties were determined for the flour of green gram. Replacing 5 and 10% of the wheat flour with green gram flour improved the mixing properties of dough and produced good acceptable bread. However, the addition of 15% green gram flour weakened the dough and lowered the quality of bread. Replacing 2.5, 5 and 7.5% of wheat flour with protein concentrate also weakened the mixing properties of the wheat dough and decreased the bread quality.  相似文献   

8.
The possible improvement of the nutritional properties of starch in barley flour-based bread by using barley genotypes varying in amylose content (3–44%) was evaluated. Breads were made from 70% whole-meal barley flour and 30% white wheat flour. Test breads were baked from waxy barley (WB), ordinary barley (OB), ordinary Glacier barley (OGB) and high-amylose barley (HAB). Each bread was baked either at conventional baking conditions (45 min, 200 °C) or at pumpernickel conditions (20 h, 120 °C). A white wheat bread (WWB) was used as reference. The resistant starch (RS) content and rate of starch hydrolysis were measuredin vitro. The glycaemic index (GI) and the insulinaemic index (II) of the high-amylose breads were determined in healthy subjects. The amount of RS (total starch basis) varied from <1% (WB) to approximately 4% (HAB) in conventionally baked bread, and from about 2% to 10% in the corresponding long-time/low-temperature baked products. The long-time/low-temperature baked HAB displayed a significantly lower rate of starch hydrolysisin vitrocompared with WWB and reduced the incremental blood-glucose response in healthy subjects (GI=71). In contrast, the GI of the conventionally baked HAB was similar to that for WWB. It is concluded that a barley flour-based bread of low GI and high RS content can be obtained by choosing high-amylose barley and appropriate baking conditions.  相似文献   

9.
A previously described method for the non-aqueous fractionation of cereal flours by sedimentation in non-aqueous solvents was carried out using flours of three wheat cultivars differing in baking performance, as well as one rye and one barley flour. The method was based on differences in the densities of starch (higher) and protein (lower). Thus, suspending finely milled flour in an inert solvent mixture with a density in between the densities of starch and protein yielded a sedimented starch fraction and a protein-rich fraction at the surface of the solvent. Further purification of this upper fraction provided a protein fraction, a middle fraction, and a lipid fraction. The protein fractions were examined by means of rheological methods such as micro-extension tests and creep-recovery tests. They also were reconstituted to standard flour with a protein content of 13.5%, which was used for micro-scale baking tests. Compared to aqueous isolated gluten, the hydrated protein fractions from wheat were much more extensible and had a lower resistance to extension. The baking performance of the wheat protein fractions was superior to gluten and comparable to the native wheat flours. The protein fraction from rye gave a wheat-like bread crumb, whereas the barley protein was not suited for bread making.  相似文献   

10.
Dextrins were extracted in water from bread made from pre-harvest sprouted wheat or standard flour supplemented with exogenousalpha-amylases. The dextrins were separated by gel permeation chromatography and the dextrin content (% of crumb weight) determined for different degree of polymerisation (DP) size classes; DP 1–2, DP 3–10, DP 11–50, DP 51–200 and DP >200. There were significant correlations between the dextrin content in each size class and crumb stickiness (r=0·84–0·91, 22 df ). The most significant correlation (r=0·96) was between total dextrin content and crumb stickiness. Addition of dextrins of various DP ranges from various sources to standard flour produced bread with sticky crumb. Again, the degree of stickiness was generally related to the amount of total dextrin in the crumb and not to size distribution of dextrins. In this instance, extensive enzymic hydrolysis of starch was not necessary to produce sticky crumb; the dextrins caused crumb stickiness directly. Addition of dextrins to reconstituted gluten–starch flour produced bread with unexpectedly low dextrin levels and correspondingly low stickiness scores. It is concluded that, to produce sticky crumb, high levels of dextrin of any size are necessary in the crumb; a sticky mass is produced when dextrins dissolve in the excess «free» water that is normally «bound» to starch, gluten and other insoluble components of bread crumb.  相似文献   

11.
Using the nine different wheat varieties, sixteen different flours were blended to achieve two protein levels 11 and 13%. Mixing characteristics of the flours were analysed by Farinograph and Mixograph. Thermal properties of flour were measured by differential scanning calorimetry (DSC). Starch gelatinisation, pasting viscosity, and gelation properties were assessed by a Rapid Visco-Analyser (RVA). Hearth bread loaves were produced from the flours using a small-scale baking method. The results from the analyses of flour were related to the properties of hearth bread loaves by multivariate statistical methods. The Partial Least Squares Regression (PLS) model (Model 1) obtained using results from grain and flour analysis (no starch analysis included) as X – matrix explained 70% of the total variance in hearth bread characteristic form ratio. If flour-pasting properties were included in the PLS1 model (Model 2) the explained variance increased to 77%. The model obtained including the DSC parameters of wheat flour explained 76% of the total variance in form ratio (Model 3). This emphasises the importance of starch in wheat flour and that it is possible to find wheat flour starch quality parameters in addition to protein quality that is important for hearth bread quality. No good models were obtained for hearth bread characteristics loaf volume and weight.  相似文献   

12.
To evaluate the effect of genotype, year and location on 1000 kernel weight, falling number, alpha- and beta-amylase activity, pasting properties, β-glucan, fructan, total starch, amylose, resistant starch and dietary fibre contents of wholemeal flour, four einkorns and one control bread wheat were cropped in Italy for two years in four different locations.  相似文献   

13.
A new gluten-free bread formulations composed of quinoa, buckwheat, rice flour and potato starch were developed in the present study. Rheological characteristics of the bread batter with increasing amount of quinoa were determined; storage (G′) and loss modulus (G″) values were also measured for investigation of viscoelastic properties. To evaluate the quality of breads; technological and physical (bake loss %, specific volume, texture, microstructure, color), chemical (protein, moisture, ash) and sensory properties were determined. All batter formulations independent of the quinoa amount exhibited pseudoplastic behavior, and G′ values were found to be higher than G″ values in expressing the solid like characteristics of the batter. Amount of quinoa flour addition did not present significant difference on bake loss%, specific volume and protein content (p>0.05); however, 25% quinoa flour bread displayed better results with its higher sensory scores and softer texture. Quinoa and buckwheat flour mixture therefore will be a good alternative for conventional gluten-free bread formulations.  相似文献   

14.
The development of anin vitroenzymic batch method for pretreatment of cereal samples prior toin vitrofermentation is presented. A statistical experimental design is described and the importance of bile and pepsin for the digestibility of starch was investigated. Day-to-day variation was studied by measuring glucose released and total starch in the digestion residue of rye flour. Four samples, wholemeal rye flour and bread, wholemeal and white wheat breads, were tested to evaluate the performance of the digestion procedure. Pepsin and bile enhanced the hydrolysis of slowly digestible starch. The extent of starch hydrolysis in rye and wheat breads (93–95%) was reproducible and about the same as using thermostablealpha-amylase. More soluble fibres were released from the wholemeal rye bread than from the wholemeal wheat bread. The procedure is an efficient method for the removal of starch and protein under physiological conditions prior toin vitrofermentation. The method can also be used as a tool for studying the solubility of dietary fibre (DF).  相似文献   

15.
In this study, the effect of immature wheat flour (IWF) on the fermentation activity of lactic acid bacteria (LAB) and on the nutritional quality properties of bread were evaluated. IWF was added in the as the ratio of 10g/100g in sourdough fermentation medium, and the fermentation activity (total LAB, pH, titration acidity (TA), and total reducing sugar (TRS)) of LAB cultures was monitored. Additionally, some physical quality characteristics (specific volume, texture profile and colour value), estimated glycaemic index (eGI), rapidly digestible starch (RDS), slowly digestible starch (SDS), and the total dietary fibre content of sourdough bread were determined. According to the statistical test, it was revealed that the IWF addition stimulated LAB growth and increased their fermentation activity. The pH of the fermentation medium decreased from 6.57 to 3.50, and TA raised from 0.13% to 1.2% in 48 h. The highest TRS content was determined in IWF enriched sourdough samples, and as a result of this, the eGI of sourdough bread increased. Compared to the control sample, the SDS and total dietary fibre content were higher in IWF added sourdough bread, and a positive correlation was noted between these two components. IWF utilisation of sourdough bread formulation increased the hardness value by nearly 50%.  相似文献   

16.
Cassava (Manihot esculenta Crantz) native starch was treated with pyroconversion and enzymatic hydrolysis to produce a pyrodextrin and an enzyme-resistant maltodextrin. Some nutritional characteristics were quantified for both compounds. Pyroconversion was done using a 160:1 (p/v) starch:HCl ratio, 90 °C temperature and 3 h reaction time. The resulting pyrodextrin contained 46.21% indigestible starch and 78.86% dietary fiber. Thermostable α-amylase (0.01%) was used to hydrolyze the pyrodextrin at 95 °C for 5 min. The resulting resistant maltodextrin contained 24.45% dextrose equivalents, 56.06% indigestible starch and 86.62% dietary fiber. Compared to the cassava native starch, the pyrodextrin exhibited 56% solubility at room temperature and the resistant maltodextrin 100%. The glycemic index value for the resistant maltodextrin was 59% in healthy persons. Its high indigestible starch and dietary fiber contents, as well as its complete solubility, make the resistant maltodextrin a promising ingredient for raising dietary fiber content in a wide range of foods, especially in drinks, dairy products, creams and soups.  相似文献   

17.
Samh seeds obtained from Al-Jouf area were ground into flour analyzed and used as a replacement for wheat in the ratio of 10, 20 and 30% for bread and 30, 60 100% for cookies. The rheological effect of the Samh flour on Saudi wheat flour was also studied. The bread and cookies obtained were evaluated physically and by sensory evaluation. The results obtained indicated that samh flour has high protein content and could be used as a replacement for wheat flour upto 30% without adversely affecting the bread specific volume much. Samh flour has improved the cookies appearance specially the colour (chocolate colour) and spreading ratio. The results also revealed that it is possible to make cookies from 100% samh flour. Due to the high protein content of the samh seeds the nutritional value of the bread and cookies made with samh flour will be improved. The results of the sensory evaluation of the bread and cookies indicated that the bread made with samh flour upto 30% has similar characters except for the crumb color and the overall acceptability which were rated as significantly inferior. The sensory evaluation of the cookies showed that the cookies made with samh flour upto 100% were significantly superior (p<0.05) to the cookies made with 100% wheat flour (control).  相似文献   

18.

Rising prevalence of hypertension is pushing food industry towards the development of innovative food products with antihypertensive effects. The aim was to study the effect of reduced sodium content and 21 % addition of wholemeal wheat sourdough (produced by Lactobacillus brevis CECT 8183 and protease) on proximate composition, γ-aminobutyric acid (GABA) and peptide content of wheat bread. Angiotensin converting enzyme I (ACE) inhibitory and antioxidant activities were also evaluated. Sodium replacement by potassium salt did not affect chemical composition and biological activities of bread. In contrast, GABA and peptides <3 kDa contents in sourdough bread (SDB) were 7 and 3 times higher, respectively, than the observed in control. ACE inhibitory and antioxidant activities of the peptide fraction?<?3 kDa from SDB was 1.7 and 2.6-3.0 times higher than control. Therefore, the combination of reduced sodium content with enriched concentrations of bioactive compounds in bread making may provide interesting perspectives for development of innovative breads towards blood pressure reduction.

  相似文献   

19.
Pinto beans were milled and then air-classified to obtain a raw high protein fraction (RHPF) followed by extrusion to texturize the protein fraction. The texturized high protein fraction (THPF) was then milled to obtain flour, and combined with wheat flour at 5, 10, and 15 % levels to make bread. The air-classification process produced flour with high concentration of lipids and phytic acid in the protein-rich fraction. However, extrusion significantly reduced hexane extractable lipid and phytic acid. However, the reduction observed may simply indicate a reduction in recovery due to bind with other components. Total protein and lysine contents in composite flours increased significantly as THPF levels increased in composite flour. Bread made with 5 % THPF had 48 % more lysine than the 100 % wheat flour (control). The THPF helped to maintain dough strength by reducing mixing tolerance index (MTI), maintaining dough stability and increasing departure time on Farinograph. Bread loaf volume was significantly reduced above 5 % THPF addition. THPF increased water absorption causing an increase in bread weights by up to 6 %. Overall, loaf quality deteriorated at 10 and 15 % THPF levels while bread with 5 % THPF was not significantly different from the control. These results support the addition of 5 % THPF as a means to enhance lysine content of white pan bread.  相似文献   

20.
The effect on baked muffins of progressively replacing wheat flour with resistant starch (RS) was studied. Muffin volume and height and the number and area of gas cells decreased significantly when the RS level reached about 15% (by weight of total formulation) or higher. Rheological properties of the raw batters were studied: the mechanical spectra of batters at 25 °C, the evolution of the dynamic moduli (G′ and G″) with rising temperatures (from 25 to 85 °C) and the mechanical spectra at 85 °C were obtained from oscillatory rheological tests. The decrease in the viscosity and in the elastic properties of the muffin batter as the flour was increasingly replaced by RS was related to the baking performance of the final baked products.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号