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1.
Commercial hard red spring, hard red winter, soft white and durum wheat brans were used to evaluate the particle size effect of wheat bran on bread baking performance and bread sensory quality. Three different particle size bran samples were obtained from each bran by grinding, not by sifting, the bran samples. The bran samples were similar in chemical composition, but different in particle sizes. Results of baking experiments showed that breads containing fine bran had lower specific loaf volume and darker crumb colour than breads containing coarse or medium size bran. Sensory test panellists found that fine bran contributed smoother crust appearance and less gritty mouthfeel than the coarse bran. The sensory panel also indicated that breads containing soft white wheat bran had significantly better flavour and mouthfeel than breads containing hard red spring wheat bran. © 1999 Society of Chemical Industry  相似文献   

2.
BACKGROUND: Alkylresorcinols (AR) are amphiphilic phenolic compounds found in high amounts in wheat, durum wheat and rye, with different homologue composition for each cereal. The effect of different amounts of added AR from these cereals on bread volume, height, porosity and microstructure was studied. Breads with added rye bran (with high levels of AR) or acetone‐extracted rye bran (with low levels of AR) were also baked, as well as breads with finely milled forms of each of these brans. RESULTS: Breads with high amounts of added AR, irrespective of AR homologue composition, had a lower volume, a more compact structure and an adverse microstructure compared with breads with no or low levels of added AR. AR were also shown to inhibit the activity of baker's yeast. There was no difference in bread volume and porosity between bread baked with rye bran and acetone‐extracted rye bran or with brans of different particle size. CONCLUSION: Irrespective of homologue composition, AR had a negative effect on wheat bread properties when added in high amounts as purified extracts from wheat, durum wheat and rye. Natural levels of AR in rye bran, however, did not affect the volume and porosity of yeast‐leavened wheat breads. Copyright © 2010 Society of Chemical Industry  相似文献   

3.
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.  相似文献   

4.
In order to assess the effect of genotype, location and their interaction on total phenolic content (TPC) of chemical extracts, the whole grains of durum and soft wheat, oat, barley and triticale were evaluated. Data showed differences in phenolic content of chemical extracts among cereal species and the analysis of variance confirmed the key role of location. Besides TPC and trolox equivalent antioxidant capacity (TEAC) values assessed by chemical extraction were compared with those obtained with an in vitro digestive enzymatic extraction. Differences were found between methanolic and enzymatic extracts, and data confirmed that enzymatic technique enhanced extraction of antioxidants but pointed out lesser differences among cereal types. The breads obtained by flours enriched with different levels of bran were also evaluated. Chemical extracts highlighted the increasing levels of antioxidants according to bran enrichments, without pointing out changes caused by baking. The enzymatic extraction instead did not show differences regarding to bran enrichments, but documented a loss in antioxidant properties of breads in respect to corresponding flours. On the other hand the scarce differences between flours and corresponding breads did not allow asserting that baking modified the TPC and TEAC, independently of the extraction methods used. Indeed, during baking process, also the observed phenolic acids profile variations did not vary the antioxidant properties of breads.  相似文献   

5.
Autoclaving process applied to wheat and rice bran samples to decrease the phytic acid content and to enhance the functional and nutritional properties (dietary fiber and phenolic content, antioxidant activity) of bran samples. All hydrothermal treatments caused significant decreases in phytic acid contents of both wheat (95.2%) and rice bran (95.6%) samples. The most effective process conditions on enhancing the total dietary fiber content for both bran samples were pH 4.0 level and 1.5 h holding time. Autoclaving treatment resulted in a decrease in total phenolic contents after holding for 90 min and at 121 °C at their native pH levels. Autoclaving for 90 min caused the greatest degree of increment in the total antioxidant activity of wheat (12%, pH 4.0) and rice bran samples (2%, pH 3.5). Autoclaving treatment was found as quite effective method for both dephytinization and enrichment of wheat and rice brans as a functional food ingredient.Industrial relevanceAuthors believe that the study presents important new information in terms of both enhancing functional properties of wheat and rice brans by hydrothermally dephytinization treatment and revealing the correlation between hydrothermal treatment and functional ingredients of brans. In this way, proposed method transforms inexpensive and easily accessible sources into important food ingredients and gives them added value. Hydrothermal treatment also enables food industry to use cereal brans as functional ingredients in the applications of both designing and enriching new and healthy food formulations.  相似文献   

6.
We completed a series of studies to assess the acceptability of zinc-fortified, cereal-based complementary foods and zinc-fortified wheat breads. Young children and their caregivers completed acceptability tests with complementary foods fortified with iron only (60 mg iron as ferrous fumarate per kilogram cereal flour), or the same level of iron and zinc (240 mg zinc as zinc oxide per kilogram cereal flour), and the caregivers completed triangle taste tests to compare the same products. A separate group of adult participants completed acceptability tests with wheat breads fortified with iron and folic acid (15 mg iron as ferrous fumarate per kilogram flour and 1.5 mg folic acid per kilogram flour) or the same levels of iron-folic acid and 2 levels of zinc (63 mg zinc or 126 mg zinc as zinc oxide per kilogram flour). Finally, a threshold test was administered to another group of adult participants to compare nonfortified wheat bread to breads fortified with zinc in 80 mg increments ranging from 80 to 400 mg zinc as zinc oxide per kilogram flour. All products were acceptable when compared to non-zinc-fortified equivalents, and were well liked by the respective participants. For the triangle tests, caregivers were not able to detect significant differences between products. For threshold tests, adult participants detected differences in breads prepared from fortified wheat flour at 80 mg, 160 mg, and 320 mg zinc per kilogram flour, but not at 240 mg and 400 mg zinc per kilogram flour, respectively, when compared to nonfortified bread equivalents. Zinc fortification of cereal flours in the ranges of fortification that were tested does not adversely affect the acceptability of complementary foods and breads prepared from these flours. Practical Application: Fortification of staple food products is a low-cost approach to deliver additional micronutrients (including zinc) to large segments of a population. Determining the acceptability of products fortified with zinc is an important step in the development of zinc fortification programs.  相似文献   

7.
Bread is a major staple food consumed daily in all parts of the world. A significant part of the human population cannot tolerate gluten, a storage protein found in wheat, rye and barley, and therefore, products made from alternative cereals are required. During this study, the bread-making potential of seven gluten-free flours, wheat and wholemeal wheat flour was compared. Fermentation potential of the different flours was determined, showing that dough development height of gluten-free and wholemeal wheat samples was lower than for wheat and oat flour. Apart from standard bread quality parameters such as loaf-specific volume and physical crumb texture, also water activity and shelf life have been determined. The shelf life of gluten-free breads was reduced compared to wheat bread. Aroma profiles were evaluated by a trained panel. Wheat, oat and wholemeal wheat breads were liked moderately, while the remaining samples had lower liking scores. Crumb grain characteristics were investigated using image analysis, and microstructure was observed by scanning electron microscopy. Overall, only breads produced from oat flour were of similar quality to wheat bread, and the utilization of buckwheat, rice, maize, quinoa, sorghum and teff flours resulted in breads of inferior quality.  相似文献   

8.
The objective of this investigation was to compare total phenolic content and antioxidant activities of various types of cereal brans enriched snack as affected by storage conditions. Extruded snacks were prepared by the addition of cereal brans (wheat, oat and rice) singly and in combination (w:r:o::2:1.5:1.5) to rice flour at 10, 20 and 30 % bran supplementation. The content of total phenolics in the extracts (conventional and microwave assisted extraction) was determined spectrometrically according to the Folin–Ciocalteu procedure and calculated as gallic acid equivalents. Radical scavenging capacity measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) methods was studied. The effect of the storage on antioxidant content and capacity showed that total phenolic content and antioxidant activities of bran enriched snacks decreased during storage at ambient temperature. However, a little increase in moisture content, water activity and free fatty acid was observed in six of month’s storage period.  相似文献   

9.
《Food chemistry》2002,77(4):479-488
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.  相似文献   

10.
D. Sabanis 《LWT》2009,42(8):1380-1389
The enrichment of gluten-free baked products with dietary fibre seems to be necessary since it has been reported that coeliac patients have generally a low intake of fibre due to their gluten-free diet. In the present study different cereal fibres (wheat, maize, oat and barley) were added at 3, 6 and 9 g/100 g level into a gluten-free bread formulation based on corn starch, rice flour and hydroxypropyl methyl cellulose (HPMC). Doughs were evaluated based on consistency, viscosity and thermal properties. Results showed that maize and oat fibre can be added to gluten-free bread with positive impact on bread nutritional and sensory properties. All breads with 9 g/100 g fibre increased the fibre content of control by 218%, but they were rated lower than those with 3 and 6 g/100 g fibre due to their powdery taste. The formulation containing barley fibre produced loaves that had more intense color and volume comparable to the control. During storage of breads a reduction in crumb moisture content and an increase in firmness were observed. The micrographs of the crumb showed the continuous matrix between starch and maize and/or oat fibre obtaining a more aerated structure.  相似文献   

11.
Selected physicochemical properties of composite [wheat/germinated brown rice (GBRF)/germinated glutinous brown rice (GGNBRF)] flours at 100:0:0 (control), 70:30:0, 60:30:10, 60:40:0 and 50:40:10 (%) were evaluated. Germination (steeping at pH 3 for 24 h at 35 °C) increased free gamma‐aminobutyric acid from 2.11 to 32.7 and 2.41 to 30.69 mg per 100 g flour for GBRF and GGNBRF, respectively. The 60:30:10 and 50:40:10 composite flours exhibited the lower peak viscosity (70.42 and 68.54 RVU, respectively). The setback viscosity of composite flours containing GGNBR was significantly lower than other flours. The presence of GBRF and GGNBRF significantly lowered specific volume and expansion ratio of breads. However, all sensory liking scores, except for appearance, were not significantly different among composite flour breads. Overall liking scores of all breads ranged from 6.8 to 7.2 (like moderately). This study demonstrated feasibility of incorporating GBRF and GGNBRF up to 50% by weight in bread formulations without compromising sensory liking.  相似文献   

12.
Commercial hard red spring, hard red winter, soft white and durum wheat brans were used to investigate the effect of wheat bran particle size on the rheological properties of doughs. Wheat brans were first coarsely ground and passed through a bran finisher to remove additional endosperm and aleurone layers. These processes increased total dietary fibre content and decreased starch content of the wheat bran samples. Three particle size distributions, for each wheat bran class, were obtained by further grinding (not by sifting) of the bran samples by different experimental mills. Coarse bran can retain significantly more water than medium or fine bran as measured by a centrifuge method, but bran particle size had no significant effect on dough water absorption. Addition of wheat bran into bread dough systems increased dough water absorption rate, reduced mixing time and decreased dough mixing tolerance as measured by farinograph. Fine particle size wheat bran decreased dough mixing tolerance and reduced mixing time compared to coarse bran. Dough containing fine particle size bran exhibited more strength than dough containing coarse bran after a 180-min rest period as measured by the extensigraph. © 1997 SCI.  相似文献   

13.
采用马克斯克鲁维酵母发酵麦麸制得富含天然酶的功能配料,分析麦麸发酵过程中纤维素酶活力变化,比较制作的麦麸面包(B1)、发酵麦麸面包(B2)、木聚糖酶麦麸面包(B3)和复合麦麸面包(B4)的膳食纤维组成及烘焙特性的差异。结果表明:马克斯克鲁维酵母具有较强的胞外β-葡萄糖苷酶生产能力,其酶活为6.98 U/g;在48 h麦麸发酵过程中,外切葡聚糖酶和β-葡萄糖苷酶的酶活不断提高,其酶活分别增加至6.06和21.70 U/g,不溶性膳食纤维(IDF)也持续降解至38.30 g/100 g。面团搅拌、醒发过程中,还原糖含量不断增加,且添加发酵麦麸的面包效果最明显。相比未发酵麦麸面包,添加发酵麦麸的面包体积、弹性及持水力都显著提升(p<0.05),气孔结构更加细腻。制作的4种面包中总膳食纤维(TDF)和阿拉伯木聚糖(AX)含量没有显著差异,而添加发酵麦麸及木聚糖酶都能促进面包中IDF和AX溶解。  相似文献   

14.
Germinated and untreated ancient (Einkorn and Emmer) and modern (Esperia) wheat flours (0, 5, 10, 15 and 20%) were used in bread dough to improve functional and nutritional properties of bread according to (3 × 2 × 5) x 2 factorial design. Utilization of wheat varieties in the germinated form increased the ash, total dietary fiber (TDF), total yellow pigment (TYP), total phenolic content (TPC), antioxidant activities, Ca, Fe and Mg content of bread, and also the most increments in those values (except TYP) were observed in Emmer flour usage. Germinated wheat flour decreased the mean phytic acid contents of bread samples from 313.32 mg/100 g to 291.81 mg/100 g compared to untreated wheat flour. The use of ancient wheat flour (einkorn and emmer) gave lower bread volume compared to modern bread wheat flour. The use of germinated wheat flour decreased the crust and crumb L* values of the breads but increased the a* and b* values. As a result, increasing ratios of germinated ancient wheat flour increased the functional component and nutritional value of the bread, and at the same time, its usage at low ratio contributed positively to the technological quality of the bread.  相似文献   

15.
选取具有代表性的裸燕麦品种,分析燕麦麸皮和胚乳所占的比例和微观结构特征;同时分析β-葡聚糖和酚酸在燕麦麸皮(果皮、种皮+糊粉层)和胚乳中的分布,并验证了现有燕麦米和燕麦粉主流加工方式的适宜程度。结果表明,在所选裸燕麦品种中,β-葡聚糖均富集在麸皮中,质量分数达8.57%,约是胚乳中含量的4.5?倍;麸皮中p-香豆酸和阿魏酸的含量分别达0.099?mg/g和1.00?mg/g,分别是胚乳中相应含量的24?倍和48?倍;在麸皮中,果皮中p-香豆酸和阿魏酸含量分别约为种皮+糊粉层中的13?倍和2.7?倍。研磨制燕麦米所得第2道麸皮中,β-葡聚糖质量分数平均为1.7%,远小于麸皮中的平均含量,加工程度适宜;而燕麦制粉所得第4道和第5道麸皮,β-葡聚糖质量分数达6.73%和7.80%,接近糊粉层中β-葡聚糖含量,加工过度。综上可知,利用分析燕麦加工所得麸皮中葡聚糖和酚酸含量,可初步判定燕麦米和燕麦粉的加工程度,为其加工提供技术支撑。  相似文献   

16.
Abstract: Selected physicochemical properties and consumer acceptance of bread prepared from composite flour (wheat:germinated brown rice:germinated glutinous brown rice flours at 60:30:10 ratio) were evaluated during storage for 0, 3, and 5 d, and compared with wheat bread (0 d, control). During storage, color profiles and water activity (from 0.947 to 0.932) of crumbs of composite flour breads slightly changed, but moisture content drastically decreased along with increasing crumb hardness (from 4.16 N to 10.37 N). Higher retrogradation in bread crumb was observed particularly for 5-d stored bread (ΔH = 2.24 J/g) compared to that of the fresh composite bread and the control (ΔH = 0.70 and 0.51 J/g, respectively). Mean (n = 116) overall liking score of the fresh composite flour bread (0 d) was slightly lower than that of the control (7.1 compared with 7.6 based on a 9-point hedonic scale). At least 76% of consumers would purchase the fresh composite flour bread if commercially available. Breads were differentiated by textural (moistness, smoothness, and softness) acceptability with canonical correlation of 0.84 to 0.87. The signal-to-noise ratio values of the 5-d stored breads were lower than the control, due mainly to the non-JAR (not-enough) intensity responses for moistness, smoothness, and softness; the mean drop of liking scores for these attributes ranged from 2.42 to 2.98. Flavor acceptability and overall liking were factors influencing consumers’ purchase intent of composite flour breads based on logistic regression analysis. This study demonstrated feasibility of incorporating up to 40% germinated brown rice flour in a wheat bread formulation. Practical Application: Our previous study revealed that flours from germinated brown rice have better nutritional properties, particularly gamma-aminobutyric acid (GABA), than the nongerminated one. This study demonstrated feasibility of incorporating up to 40% germinated brown rice flour in a wheat bread formulation. In the current U.S. market, this type of bread may be sold as frozen bread that would have a longer shelf life, or may be supplied as a food-service product that would be made-to-order or made fresh daily as currently practiced in some major grocery stores.  相似文献   

17.
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...  相似文献   

18.
对小麦进行适度脱皮,既能去除粗纤维和表面污染物,还能较好的保留微量营养素.以高筋、中筋和低筋小麦为原料,研究4%脱皮率对不同筋力小麦粉及其馒头品质的影响.结果表明,高筋和低筋小麦脱皮后糊化参数均有所提高,而中筋小麦有所下降;脱皮后,高筋、中筋和低筋小麦粉破损淀粉质量分数分别增加了6.0%、2.6%和4.2%;高筋和低筋...  相似文献   

19.
《Food chemistry》2001,74(4):493-498
Over the past two decades selenium (Se) intakes have fallen in the UK and elsewhere in Europe, as a result of reduced imports of Se-rich, high protein wheat for bread-making flour from North America and Canada. However, no analyses of the Se content of Irish flours/breads or other foods have been published, thus making it difficult to estimate the daily dietary Se intakes in Ireland. In the present study, the Se content of selected Irish foods, especially breads and flours, was determined by hydride generation atomic absorption spectrometry after acid digestion. Less refined Irish wheat flours (wheatmeal, course wholemeal, wheatbran) had higher Se levels (7.7–9.9 μg/100 g) than the more refined flours (plain, self-raising, baker's, strong; 6.0–6.9 μg/100 g). Irish brown breads had higher Se levels (8.6–12.9 μg/100 g) than those of white bread (6.6 μg/100 g). In conclusion, it appears that Irish flours and breads do not contain as much Se as North American or Canadian flours/breads and contain only slightly more Se compared with those currently used in the UK.  相似文献   

20.
Zusammenfassung Kommerzielle Weizenkleien des Handels (9 Muster) enthielten zwischen 32 and 46 mg/g TS Phytinsäure, das entspricht einer 3- bis 5 fachen Anreicherung gegenüber Ganzkornweizen, bei Ballaststoffgehalten von 32 bis 47% FS. Weizenkeime des Handels (4 Muster) besaßen 15 bis 18 mg/g TS Phytinsäure bei Ballaststoffgehalten von 9–10% FS. Der Phytinsäuregehalt ließ sich auf unter 1% des Ausgangswertes reduzieren, wenn Weizenkleien und -keime mit Natriumcitratpuffer pH 5,25 1/2 h bei 40 °C extrahiert und mit Wasser nachgewaschen wurden. Der dabei entstehende erhebliche Substanzverlust von 34–47% bei Weizenkleien and 60–73% bei Weizenkeimen ging mit einer Erhöhung der Ballaststoffmenge (phytatfreie Weizenkleie: 55–65% FS, phytatfreie Weizenkeime: 18–26%) einher. Mit dieser sehr einfachen, schnellen Extraktion lassen sich also Weizenkleien praktisch phytinfrei herstellen, so daß mögliche negative ernährungsphysiologische Effekte bei zusätzlicher Anreicherung von Ballaststoffen ausgeschaltet werden können.
Phytic acid in wheat bran and germ products. How to remove phytic acid from these products
Summary Commercial wheat bran (nine samples) and germ products (four samples) purchased from local shops were analysed for phytic acid, dietary fibre and ash contents. Phytic acid in wheat brans ranged over 32 to 46 mg/g dry mass and in wheat germ products over 15 to 18 mg/g dry mass, the dietary fibre contents ranged over 32 to 47% and 9 to 10%, respectively. The phytic acid level can be reduced to less than 1 % of the original content by extraction with sodium citrate buffer pH 5.25 for 0.5 h at 40 °C, followed by washing with water. As a consequence, 34–47% and 60–73% of the soluble material was lost from bran and germ products, respectively; coincidently the dietary fibre content increased to 55–65% in wheat brans and 18 to 26% in wheat germ products. Such a simple and fast method enables wheat brans to be produced practically free of phytic acid, resulting in the removal of possible detrimental effects of reduced mineral availibility by increasing dietary fibre levels.


Veroffentl.-Nr. 5732 der Bundesforschungsanstalt für Getreideund Kartoffelverarbeitung, Detmold  相似文献   

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