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1.
Bread was prepared from wheat flour and wheat flour fortified with either 3, 5, and 7% legume hulls or insoluble cotyledon fibers, or with 1, 3, and 5% soluble cotyledon fibers isolated from pea, lentil, and chickpea flours. Incorporation of hulls or insoluble fibers resulted in increases in dough water absorption by 2–16% and increases in mixing time of dough by 22–147 sec. Addition of soluble fiber resulted in decreases in water absorption as the substitution rate increased and similar mixing times to the control dough. Loaf weights of breads containing hulls or insoluble fibers were generally higher than that of control bread at 149.4–166.5 g. However, the loaf volume of breads fortified with legume hulls and fibers (685–1,010 mL) was lower than that of the control bread (1,021 mL). Breads containing soluble fibers were more attractive in terms of crumb uniformity and color than breads containing either hulls or insoluble fibers. Breads fortified with legume hulls and fibers were higher in moisture content than control bread regardless of the type, source, or fortification rate. Bread fortified with up to 7% hulls or insoluble cotyledon fibers or up to 3% soluble cotyledon fibers, with the exception of 7% insoluble pea fiber, exhibited similar firmness after seven days of storage compared with the control bread, despite their smaller loaf volume. Breads containing hull fibers exhibited the lowest starch transition enthalpies as determined by DSC after seven days of storage, while the starch transition enthalpies of breads containing added soluble or insoluble fiber were not significantly different from the control bread.  相似文献   

2.
A method for the determination of vitamins D2 + D3 in fortified milk is described. Vitamins D2 and D3 are extracted from the saponified sample and converted to isotachysterols with antimony trichloride. The isotachysterols are quantitated using liquid chromatography with ultraviolet detection at 301 nm, which is the absorption maximum. At this wavelength other materials present in the sample do not interfere with the analysis of isotachysterols and therefore a cleanup step is avoided. Recoveries of vitamin D added to skim milk were 98.1% (SD 5.3), 96.7% (SD 3.3), and 96.0% (SD 5.1) for samples fortified with 200, 400, and 600 IU/quart, respectively. For whole milk, recoveries were 102.0% (SD 6.5) and 97.1% (SD 3.5) in samples fortified with vitamin D equivalent to 200 and 400 IU/quart, respectively. The detection limit for vitamin D is 40 IU/quart.  相似文献   

3.
The assay of dehydro-l -ascorbic acid (DHAA) in dough and bread was done by reduction of DHAA to l -ascorbic acid (AA) in aqueous dithiothreitol (DTT) at pH 6–7 followed by quantitation of the AA using HPLC with electrochemical detection. At room temperature and pH 6.6, with 4.0 equivalents of DTT, the conversion of DHAA to AA was stoichiometric after 5 min. In mixograms on flour-water doughs, DHAA added in dimeric form at 200 ppm had no effect on absorption but increased mixing time by 9–19% with the same effects occurring in full-formula doughs. AA added to doughs did not affect mixing peak time or absorption. Mixing bread doughs with an initial level of 25–200 ppm of AA based on flour (14% mb) produced DHAA in the freshly mixed doughs at concentrations of 20–51 ppm, or from 80 to 26% of AA added. During ≈120 min of fermentation and proofing, the levels of AA in the doughs increased by 4–10 ppm. Mixing bread doughs with an initial level of 25–200 ppm of DHAA produced no AA in the freshly mixed doughs, but the proofed doughs and fresh breads contained 4–10 ppm and 7–49 ppm of AA, respectively. Fresh bread made from dough with 200 ppm of AA retained 66% total vitamin C (110 ppm of AA + 21 ppm of DHAA), whereas bread made with 200 ppm of DHAA retained 9.5% total vitamin C (13 ppm of AA + 6 ppm of DHAA). DHAA was 2–4 times more effective in improving loaf volume than an equal weight of AA in no-time dough, and 1.5–2 times more effective in straight-dough. In straight-dough bread made with a commercial bread flour, increasing concentrations of DHAA markedly improved bread up to ≈20 ppm, beyond which overoxidation occurred rapidly. In contrast, increasing concentrations of AA improved bread up to ≈150 ppm with a broad tolerance up to 200 ppm. The improving action of DHAA was independent of the concentration of air in the mixing bowl, and DHAA was much more heat-labile than AA.  相似文献   

4.
We compared the effects of spontaneous fermentation of the bran fraction and fermentation with added yeast or added yeast and lactic acid bacteria (Lactobacillus brevis) on the quality of wheat bread supplemented with bran. Prefermentation of wheat bran with yeast or with yeast and lactic acid bacteria improved the loaf volume, crumb structure, and shelf life of bread supplemented with bran. The bread also had added flavor and good and homogenous crumb structure. Elasticity of the crumb was excellent. Spontaneous fermentation of the bran fraction did not have the same positive effects on bread quality. The microstructure of the breads was characterized by light microscopy. The positive effect of fermentation of bran on bread quality was evident when comparing the well‐developed protein network structure of the breads baked with fermented bran with the control bread. Prefermentation of the bran with yeast and lactic acid bacteria had the greatest effect on the structure of starch. The starch granules were more swollen and gelatinized in the breads made with prefermented bran. The pretreatments of the bran fraction had no detectable effect on the microstructure of the cell wall particles in the test breads.  相似文献   

5.
Hydroxypropyl methylcellulose (HPMC) is a substituted cellulose that reduces serum cholesterol at modest intake levels. HPMC has also been used for decades in gluten-free breads at a level to optimize loaf volume. Because consumers resist the consumption of whole wheat breads, the sensory and physical properties of all oat and barley breads incorporating HPMC were evaluated. Oat and barley also contain β-glucan, a glucose polymer similar to HPMC that also lowers cholesterol. The textural and sensory properties of the breads were determined by instrumental and chemical methods and sensory panels. HPMC increased the loaf volume of the breads by up to 2 times and decreased hardness immediately after baking and after up to 3 days of storage. Barley bread with HPMC was rated the highest in overall acceptability by sensory panelists compared to oat and wheat breads with or without HPMC.  相似文献   

6.
White bread was fortified individually with fat-coated l -ascorbic acid (AsA), cold-water-dispersible (CWD) β-carotene, and CWD all-rac-α-tocopheryl acetate (ToAc) at levels of 64, 5, and 100 mg, respectively, of active ingredient per 100 g of flour (14% mb). The freshly baked puploaves retained 76, 67, and 96% of added antioxidant, respectively. To extract ToAc quantitatively from bread or dough, dimethyl sulfoxide (DMSO) gave better results than hexane, which indicated that ToAc was in a partially bound state. “Protein-encased” (PE) β-carotene did not impart a yellow color to bread crumb and had one-fourth higher retention in fresh bread when compared to CWD β-carotene. In loaves stored at 25°C for one to seven days, AsA disappeared rapidly and PE β-carotene disappeared slowly; CWD β-carotene and ToAc were stable. In spite of storage loss, bread fortified with PE β-carotene retained significantly higher levels of β-carotene when compared to CWD β-carotene. One serving size (one slice, 28 g) of three-day-old bread fortified with one of the three antioxidants was calculated to provide 7, 120–150, and 13–16%, respectively, of the adult recommended daily allowances (RDA) for vitamins C, E, and A. When bread was fortified with both fat-coated AsA and CWD β-carotene and stored for five days, no protecting effect on the retention of the antioxidants was found.  相似文献   

7.
Lipids, especially polar lipids, can improve loaf volume, grain and texture, and delay staling in bread. Oats (Avena sativa L.) are rich in total and polar lipids. We have investigated the effect of oat lipids in a bread formulation on loaf volume, appearance, and bread staling. Oat oil was fractionated into polar and nonpolar fractions by water‐degumming. Crude oat oil and shortening (at 3%) increased loaf volume by ≈11% over the zero lipid formulation. The polar lipid fraction increased loaf volume by nearly the same amount when added at only a 0.5% level. The addition of 3% crude oat oil or 0.7% oat oil polar fraction significantly delayed bread firming and starch retrogradation; the difference between oat lipids and shortening was more evident at the end of a four‐day storage period. Oat lipids had a stronger relative effect on bread from a weak flour (10% protein) than from a strong flour (14% protein). The effects of oat oil in the bread formulation could be related to the amphipathic character of polar lipids in oats that enables them to interact with starch, proteins, and other bread components.  相似文献   

8.
High‐amylose wheat flour was used to substitute for normal wheat flour in breadmaking and formation of resistant starch (RS) in bread during storage was determined. Substitution with high‐amylose wheat flour (HAF) decreased peak and final viscosities, breakdown, and setback. Doughs with HAF substitutions were weaker and less elastic, and absorbed more water than those of the normal wheat flour. After baking, RS contents in breads with 10, 30, and 50% HAF substitutions were 1.6, 2.6, and 3.0% (db), respectively, higher than that of the control (0.9%, db). The levels of RS increased gradually during storage for one, three, and five days. With substitutions of 30 and 50% HAF, the total levels of dietary fiber (DF) and RS in bread after five days of storage were 15.5 and 16.8% (db), respectively, as compared to 13.0% (db) in bread from the normal wheat flour. The loaf volumes and appearances of bread crumbs made from HAF substitutions of 10 and 30% were not significantly different from those of the control, whereas the substitution with 50% HAF decreased loaf volume and resulted in inferior appearance of breadcrumbs. The firmness of breadcrumbs increased along with increase in the level of HAF substitutions after baking. During storage, the firmness of breadcrumb with 10% HAF substitutions was higher than that of the control, whereas breads with 30 and 50% HAF substitutions had similar firmness to the control. As a result, HAF might be used to substitute for up to 50% normal wheat flour to make bread with acceptable bread quality and significantly high amount of RS.  相似文献   

9.
A 7:3 (w/w) mixture of wheat fiber (WF) and psyllium husk fiber (PHF) was substituted for 10wt% of flour on a 14% mb, and the protein in the blend was restored to 10.3% by incorporating vital wheat gluten. After adding 0.5% sodium stearoyl 2-lactylate, the blend (100 g) was fortified with a combination of fat-coated ascorbic acid (AsA), proteinencased (PE) β-carotene, and cold-water-dispersible (CWD) all-rac-α-tocopheryl acetate (ToAc) at levels of 72, 5.6, and 115 mg, respectively, of active material. Adding the fiber ingredients to the pup loaf formula increased water absorption 25% and mixing time 50% and imparted stickiness to the dough. The fiber and antioxidant bread showed a 10% reduction in loaf volume and a somewhat inferior crumb grain with an off-color caused by small, black specks on a dark gray background. The crumb of the fiber and antioxidant bread remained much softer than control bread during one to seven days of storage at room temperature. Caramel coloring masked the off-color. AsA was lost significantly faster in the fiber and antioxidant bread than in antioxidant bread; the losses of AsA were 97 and 86%, respectively, after three days at 25°C. Approximately 25% of β-carotene was lost from the fiber and antioxidant bread after three days, and 33% after seven days, but the loss of ToAc was <10%. One serving size (one slice, 28 g) of fiber and antioxidant bread was calculated to provide 2.1 g of dietary fiber, or ~8% of daily value, of which ~30% was soluble. The three-day-old slice also contained vitamin E and vitamin A (as β-carotene) at 120–150% and 12–15%, respectively, of the adult recommended daily allowances, but with 16% fewer calories than white pan bread.  相似文献   

10.
Zinc and aluminum ions as chloride or sulfate salts at 50–500 ppm metal ion (flour basis) had no detrimental effect on fermentation of yeastleavened dough. Increased mixing times (≈10–50%) due to addition of aqueous solutions of zinc (250–500 ppm) or aluminum (150–250 ppm) ions to a bread formula was overcome by withholding salt until the final mixing stage. Breads made from commercial flours (12.5% protein) containing zinc (250–500 ppm) or aluminum (150–250 ppm) ions and no oxidant had improved loaf volume and crumb grain when compared with control bread, and no off-taste. Additionally, breads with added zinc or aluminum had better crumb grains and slower firming rates when compared with breads containing optimum l -ascorbic acid (50 ppm) or potassium bromate (20 ppm). Breads made from commercial flours (11.1% protein) and three laboratory flours (11.4–13.6% protein) containing zinc (250 ppm) or aluminum (150 ppm) ions also had improved loaf volumes and crumb grains. Zinc or aluminum ions in combination with l -ascorbic acid, but not potassium bromate, had a detrimental effect on bread quality. Scanning electron microscopy of freeze-dried bread doughs revealed that zinc and aluminum ions enhanced the film-coating property of gluten. One serving (one slice, 28 g) of bread made with 250 ppm zinc ion would provide 25% of the adult recommended dietary allowance of zinc.  相似文献   

11.
Addition of raw ground almond has been shown to improve loaf quality (e.g., loaf specific volume) of soy bread. To better understand the effects of almond addition to soy bread and to follow these through storage, nuclear magnetic resonance spectroscopy relaxation times and cross-relaxation experiments were performed. Spin-spin relaxation times of water protons were similar for the two soy breads, and therefore changes of water interactions with the other components of the soy breads (with and without almond) were not considered to be major contributors to the differences in loaf quality observed between these breads. Additionally, T2 values of water protons were found to have a similar decreasing trend during storage, especially up to day 3, for all of the products studied. On the other hand, during storage, lipid proton relaxation times exhibited only small changes in wheat and regular soy bread, whereas the soy-almond bread showed a major decrease of lipid proton mobility in particular after day 3 and up to day 10. These findings may indicate that, after a few days of storage, the lipid fraction contributes to better plasticization of the soy bread with almond, which can affect acceptability and storage stability of the final product. Thus, the higher amount of lipids introduced in the almond-enriched soy bread is likely to be responsible for the improved loaf quality and may significantly affect shelf stability of the soy-containing product.  相似文献   

12.
Vitamin A (vitamin A palmitate) and vitamin E (alpha-tocopheryl acetate) levels were determined in 77 samples of fortified infant formulas manufactured by 4 firms in the United States from 1981 to 1983 and were compared by formulation base (soy, milk) and manufacturing firm. For vitamin A and vitamin E, the mean values (IU/100 kcal) were 454 +/- 95 (range 248-614) and 2.0 +/- 0.7 (range 1.1-5.0), respectively. No significant differences (alpha = 0.05) were found in levels (IU/100 kcal) of vitamin A and vitamin E between milk- and soy-based formulas. When the mean vitamin A and vitamin E levels of formulas produced by the various firms were compared on an IU/100 kcal or percent of label declaration basis, significant differences (alpha = 0.05) were found among firms. Mean vitamin A levels for the various products compared to label declarations ranged from 126% of declared for the ready-to-use formulas to 139% of declared for the powders. Mean vitamin E levels ranged from 97% of declared for ready-to-use formulas to 118% of declared for concentrates. Except for one sample that contained 248 IU vitamin A/100 kcal, the formulas met the requirements of the 1980 Infant Formula Act.  相似文献   

13.
Samples of commercially prepared white, whole wheat, flax, and multigrain breads were analyzed by a rapid RP-HPLC method for the presence of the lignan secoisolariciresinol diglucoside (SDG). SDG was detected only in products containing flax, with concentrations ranging from 0.06 to 1.98 microM/g of DW (19-602 microM/loaf). Full-fat flax meal, powdered aqueous alcohol extracts of flax seed, and SDG were added to a white bread mix and baked into loaves in a domestic bread maker. Quantitative recovery of SDG from the test breads was observed when SDG was added; however, when flax meal or aqueous alcohol extracts were added, only 73-75% of the theoretical yield of SDG was recovered. SDG was also detected in commercially prepared flax cookies, bagels, and muffins with concentrations ranging from 0.26 to 2.93 microM/g of DW. The extent of grinding of the flax seed was also shown to have a significant effect on the recovery of SDG from both flax meal breads and baked goods, with extraction of SDG from finely ground samples greater than that from course material.  相似文献   

14.
In situ enrichment of bread with arabinoxylan‐oligosaccharides (AXOS) through enzymic degradation of wheat flour arabinoxylan (AX) by the hyperthermophilic xylanase B from Thermotoga maritima (rXTMB) was studied. The xylanolytic activity of rXTMB during breadmaking was essentially restricted to the baking phase. This prevented problems with dough processability and bread quality that generally are associated with thorough hydrolysis of the flour AX during dough mixing and fermentation. rXTMB action did not affect loaf volume. Bread with a dry matter AXOS content of 1.5% was obtained. Further increase in bread AXOS levels was achieved by combining rXTMB with xylanases from Pseudoalteromonas haloplanktis or Bacillus subtilis. Remarkably, such a combination synergistically increased the specific bread loaf volume. Assuming an average daily consumption of 180 g of fresh bread, the bread AXOS levels suffice to provide a substantial part of the AXOS intake leading to desired physiological effects in humans.  相似文献   

15.
Pup‐loaf bread was made with 10, 30, and 50% substitution of flour with wheat starch phosphate, a cross‐linked resistant starch (XL‐RS4), while maintaining flour protein level at 11.0% (14% mb) by adding vital wheat gluten. Bread with 30% replacement of flour with laboratory‐prepared XL‐RS4 gave a specific volume of 5.9 cm3/g compared with 6.3 g/cm3 for negative control bread (no added wheat starch), and its crumb was 53% more firm than the control bread after 1 day at 25°C, but 13% more firm after 7 days. Total dietary fiber (TDF) in one‐day‐old bread made with commercial XL‐RS4 at 30% flour substitution increased 3–4% (db) in the control to 19.2% (db) in the test bread, while the sum of slowly digestible starch (SDS) plus resistant starch (RS), determined by a modified Englyst method, increased from 24.3 to 41.8% (db). The reference amount (50 g, as‐is) of that test bread would provide 5.5 g of dietary fiber with 10% fewer calories than control bread. Sugar‐snap cookies were made at 30 and 50% flour replacement with laboratory‐prepared XL‐RS4, potato starch, high‐amylose (70%) corn starch, and commercial heat‐moisture‐treated high‐amylose (70%) corn starch. The shape of cookies was affected by the added starches except for XL‐RS4. The reference amount (30 g, as‐is) of cookies made with commercial XL‐RS4 at 30% flour replacement contained 4.3 g (db) TDF and 3.4 g (db) RS, whereas the negative control contained 0.4 g TDF and 0.6 g RS. The retention of TDF in the baked foods containing added XL‐RS4 was calculated to be >80% for bread and 100% for cookies, while the retention of RS was 35–54% for bread and 106–113% for cookies.  相似文献   

16.
White pan breads were prepared with flour highly fortified with calcium (Ca), using Ca carbonate (Ca, 38.8%) or a high Ca whey powder (Ca, 5.6%) as the Ca source; bread was also prepared using Ca carbonate plus lactose. Ca was added to flour at 924 mg/100 g of flour, a level 4.4 times higher than specified under the U.S. enrichment standards. Breads were dried and finely ground to prepare test diets (Ca, 0.5%) which were then fed to growing rats for four weeks (growth phase) or eight weeks (approaching maturity). At either interval, femur ash content, femur Ca content, femur strength, or Ca absorption values did not differ significantly among groups fed breads fortified either with Ca carbonate, Ca carbonate + lactose, or whey. Thus, breads can be highly fortified with Ca carbonate to be labeled as “high” in Ca, and this Ca may be as well absorbed and utilized as dairy Ca.  相似文献   

17.
All forms of baking and processing cause a loss of nutrients, including vitamin E, but little is known about these occurrences or if they could be avoided. The objective of this research was to study the incorporation of palm oil and the stability of vitamin E in palm oil during breadmaking. Wheat meal and rye breads were baked with and without the addition of 0, 2, 5, or 8% palm oil. The eight E group vitamers (tocopherols and tocotrienols) were extracted by using accelerated solvent extraction, freeze dried, and then analyzed with normal‐phase HPLC. Compared with the controls, the inclusion of palm oil was found to increase the quantity of all forms of vitamin E in the final baked products. It is concluded that palm oil is effective in increasing the vitamin E content of whole grain bread.  相似文献   

18.
Yeast bread is a major contributor of sodium in the American diet. Because of its functional impact on dough rheology and the quality of the final baked product, simply reducing the level of sodium chloride (salt) in the formula or replacing it with salt substitutes has found minimal success. The objective of this study was to determine the effect of sea salt containing 57 or 64% less sodium than common sea salt on the breadmaking properties and consumer acceptability of bread. The sodium content of the salt had no effect on dough strength, mixing time, gas production, loaf volume, or crumb grain. The flavor and overall liking of breads containing sea salt with 57 and 64% less sodium content were scored only slightly lower than bread containing the control salt by an untrained panel of 118 consumers. No difference in texture and no unacceptable flavor notes in the bread made with reduced‐sodium salts were reported. Thus, it appears that use of reduced‐sodium sea salt is a satisfactory alternative to reduce the sodium content of bread.  相似文献   

19.
The effect of baking method on folates of rye and wheat breads, as well as the effect of sourdough fermentation of rye, were examined. Sourdough fermentations were performed both with and without added yeast, and samples were taken throughout the baking process. Samples were analyzed microbiologically for their total folate content after trienzyme extraction. Individual folate vitamers were determined by HPLC after affinity chromatographic purification. The lowest folate contents for both rye and wheat breads were found from breads baked without added yeast. Total folate content increased considerably during sourdough fermentation due to increased amounts of 10‐HCO‐H2folate, 5‐CH3‐H4folate, and 5‐HCO‐H4folate. Baker's yeast contributed markedly to the final folate content of bread by synthesizing folates during fermentation. Proofing did not influence total folate content but changes in vitamer distribution were observed. Folate losses in baking were ≈25%. The variety of sourdoughs and baking processes obviously lead to great variation in folate content of rye breads. The possibilities to enhance natural folate content of rye bread by improving folate retention in technological processes and by screening and combining suitable yeasts and lactic acid bacteria should be further investigated.  相似文献   

20.
Flours obtained by a specific polishing process were used to prepare sourdough and bread. Three fractions designated C‐1 (100–90%), C‐5 (60–50%), and C‐8 (30–0%) were studied. The pH, total titratable acidity levels, and buffering capacity of sourdoughs made from polished flours were significantly different from those of the control sourdough with No. 1 Canada Western Red Spring (CW), and they provided sourdough breads with better qualities than that of CW. The growth of lactic acid bacteria and yeast in polished flour sourdoughs were significantly accelerated during fermentation over that in CW sourdough. Higher maturation of polished flour sourdoughs softened the hardness of mixed dough. The intricate network of honeycomb structure gluten and uneven surface of starch granules were distinctly observed in SEM images. Substitutions of C‐5 or C‐8 sourdoughs for CW significantly increased the loaf volume and softened breadcrumbs more than CW sourdough. Flour qualities of polished flours such as suitable acidity and good buffering capacity caused by the bran fraction were effective for better growth and longer life of yeast in the dough during fermentation. Therefore, application of polished flours in sourdough bread would improve rheological properties of dough and bread as compared with CW sourdough.  相似文献   

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