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White breads with Yudane dough (Yudane bread) were made from commercial hard flour by the no first fermentation method. Yudane dough was prepared by mixing boiling water and flour at a ratio of 1:1. The dough at 20 and 40% (w/w, flour base) was added to the total bread dough. In the Yudane bread making method, an extended final proof, lower dough gas retention and gassing power, as well as specific loaf volume were observed compared to conventional bread making (control) without Yudane dough. Also, the moisture content of the Yudane breads increased with increasing water absorption for bread making. The total and reducing saccharide and maltose contents in the water-soluble fraction of Yudane bread also increased with the volume of added Yudane dough. The Yudane breads were very soft just after baking, and the staling (temporal changes in hardness) and starch retrogradation of the breads were somewhat reduced compared to the control. Further, the breads showed generally larger cohesiveness, i.e., the index of bread elasticity. Kinetic analysis indicated reduced bread staling and starch retrogradation rates compared to control. The data showed that the slow staling and unique texture of the Yudane breads were mainly due to the high moisture content, saccharide contents, and flour amylases-modification of swollen and gelatinized starch in the breads, which was related to the higher water absorption and starch swelling and gelatinization levels of the added Yudane dough.
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... As such, it can add value and reduce waste. However, when crust is used for bread making, it inhibits gluten network formation at the dough developing stage because of the large amounts of gelatinized and damaged starches (GS and DS) present, so the bread making qualities (BMQs) of the dough deteriorate noticeably (Santiago et al., 2015b;Yamauchi et al., 2014). Therefore, using crust for bread making is not very common. ...
... It is believed that an increase in SLV of bread promotes water loss from dough at the baking stage due to the increase in the bread surface area. These results also corresponded to reports that breads with a smaller SLV or made from high water absorbing dough will produce bread with high moisture content (Santiago et al., 2015b;Tsai et al., 2012;Yamauchi et al., 2014). ...
... In addition, all saccharide contents of breads with CG were basically high and, in particular, total saccharide, reducing saccharide and maltose were significantly higher compared with the Control. These results basically agreed with what has been reported in previous papers concerning Yudane bread produced with gelatinized and swollen flour paste and bread made by adding gelatinized sweet potato powder (Santiago et al., 2015b;Yamada et al., 2004;Yamauchi et al., 2014). These studies also reported that when materials containing gelatinized, swollen starch and various other polysaccharides, such as Yudane dough and gelatinized sweet potato powder, are added to dough, they produce more total and reducing saccharides and maltose in the dough compared to the Control without these materials. ...
A large amount of bread crust is generated in the production of sandwiches and other bread products which, is not sufficiently used as food. If this crust can be reused effectively in the bread making process, it can add value, reduce waste, and improve the flavor and texture of bread. However, an excess amount of gelatinized starch (GS) in crust inhibits gluten network formation in bread dough and greatly decreases bread making qualities (BMQs). In this study, we investigated the optimal amount of two bakery enzymes, α-amylase (AM) and hemicellulase (HC), that can be added to improve the BMQs of crust-added dough. The optimal amounts of the enzymes were determined using response surface methodology and Solver, an Excel add-in software. The results showed that BMQs, specific loaf volume (SLV), gas retention of dough (GRD) and staling of dough and bread with added crust gel (CG) and optimal amounts of AM and HC were drastically improved compared to those without additional enzymes. It was concluded that response surface methodology and Solver are effective methods to easily determine the optimal amounts of the two enzymes to add to CG-supplemented dough to obtain high SLV and desirable texture, flavor and taste. The only negative aspect is poor bread color.
... The main reason is that when MP is added to bread dough, the gluten network of the dough deteriorates due to GS and DFs, especially insoluble DFs, remarkably decreasing the bread making properties. On the other hand, the use of raw materials containing a large amount of gelatinized or swollen starch, such as MP, for bread making results in positive effects, such as a slightly sweet taste, low staling, and sticky texture, as reported by Murayama et al., 2015 andYamauchi et al., 2014. In addition, potato starch in various starches has been found to have a very high swelling power and viscosity when heated in water, and its GS retains a large amount of water (Hossen et al., 2011;Li and Yeh, 2001). ...
... This seems to be related to the fact that the SLV of MP bread is significantly lower than the others, and that the bread's surface area is small and the moisture evaporation during storage is suppressed. These results also correspond to reports that breads with a smaller SLV or with gelatinized starch have less moisture evaporation during baking and storage (Santiago et al., 2015b;Tsai et al., 2012;Yamauchi et al., 2014). ...
... All saccharide contents in MP+E bread, except for glucose and fructose, were significantly higher than those of the others. The reducing sugar, glucose, fructose, and especially maltose of MP and MP+E breads also showed significantly high values (Santiago et al., 2015b;Yamada et al., 2004;Yamauchi et al., 2014). They also reported that when the materials containing gelatinized, swollen starch, and various other polysaccharides, such as Yudane dough and gelatinized sweet potato powder, etc., are added to the dough, obviously greater total and reducing saccharides, and maltose were produced in the dough compared to the Control without these materials. ...
Bread substituted with mashed potato (MP) instead of wheat flour has been attracting attention because of added components, such as gelatinized starch (GS), dietary fibers (DFs), vitamins, and minerals, etc., that have a beneficial effect on the nutritional value, texture, flavor, and taste of the bread. On the other hand, excess amounts of GS and DFs in MP inhibits gluten network formation in dough and greatly deteriorates the bread making quality (BMQ). In this study, we investigated the optimal addition of two types of bakery enzymes, α-amylase (AM) and hemicellulase (HC), to improve the BMQ of MP-added dough. Optimal amounts of added enzymes were determined using the response surface methodology (RSM) and optimization technique (OT). As the results, BMQ, such as specific loaf volume (SLV), gas retention of dough, and bread staling, of MP dough and bread with optimal concentrations of AM and HC were remarkably improved compared to those without enzymes. These results showed that RSM and OT were effective methods to reasonably and easily derive the optimal concentrations of multiple enzymes, resulting in a good quality MP-supplemented bread with high SLV, desirable texture, flavor, and taste, but not crust color.
... Yudane bread is characteristically moist, very soft, and sticky with a texture like cooked rice. It also has a desirable flavor, slightly sweet taste, good crust color, and slow staling as evaluated mainly by hardening (hardening) compared to conventional bread (control) (Shibata and Kato, 2001;Fukazawa and Kainuma, 2004;Yamada et al., 2004, Yamauchi et al., 2014. Thus, new items produced using the Yudane dough bread making method (Yudane method) are continuously being developed, and these breads have a market worth of more than a hundred billion yen in Japan. ...
... On the other hand, kinetic analysis of Yudane bread showed that its hardening rate constant (HRC) and retrogradation rate constant of starch gel in the bread were lower than those of the control. The main factors responsible for these phenomena in Yudane bread are the high moisture and sugar contents (Yamada et al., 2004;Yamauchi et al., 2014). ...
... Study of the hardening behavior of Yudane bread during storage has been conducted at room temperature (20℃), whereas hardening analysis at various storage temperatures has not yet been explored (Yamada et al., 2004;Yamauchi et al., 2014). Moreover, it is very important to predict the hardening behavior of actual bread products during distribution from the point of manufacture to the store shelf, a condition characterized by random temperature changes in a non-steady-state. ...
Pullman type white breads with or without Yudane dough at 10 and 20% (w/w, flour base) were made by the no first fermentation method. Yudane dough was prepared by mixing boiling water and flour at a 1:1 ratio. The breads were stored at various temperature conditions and then subjected to analyses of bread hardening (temporal changes in hardness), hardening rate constant of bread (HRC), and simulation of hardening behavior using a hardening model. The results were as follows: The hardening of all breads slowed with the increase in storage temperature. The hardening of breads made with Yudane dough (Yudane breads) was slower than that without Yudane dough (Control) at any storage temperature. The HRC of all breads sharply decreased with the increase in storage temperature. By using the hardening model, the hardening behavior of all breads stored at various temperature conditions was simulated with considerable accuracy.
... The "Yukone", "Yudane" or "Tangzhong" (water roux) method is a Japanese breadmaking technique that produces bread with a soft and sticky texture, and a high tolerance to staling (Kim et al., 2017;Naito et al., 2005;Yamauchi et al., 2014). A part of the wheat flour (usually 5-10% of the total flour mass) is mixed with water at > 60°C to trigger starch pre-gelatinization; the mixture is cooled to room temperature, and added to the other ingredients to obtain the dough (Naito et al., 2005). ...
... A part of the wheat flour (usually 5-10% of the total flour mass) is mixed with water at > 60°C to trigger starch pre-gelatinization; the mixture is cooled to room temperature, and added to the other ingredients to obtain the dough (Naito et al., 2005). The literature suggests that the slow staling, low hardness and high cohesiveness of Yudane breads is mainly due to an increase in swollen starch which, in turn, has been related to doughs with both higher water absorption and amylase enzymatic phenomena (Yamauchi et al., 2014). ...
... These results are consistent with literature (Kim et al., 2017;Yamauchi et al., 2014;Zettel et al., 2014). Kim et al. (2017) reported a decrease in hardness in rice bread samples prepared with GBF. ...
Although brown wheat flours are healthier than refined ones, baking quality is poor. To improve the workability and quality of brown wheat flour, we tested the addition of gelatinized flour during the production of salt-free bread. Dough rheology and bread quality were investigated in two trials. The first tested the addition of three levels of water and two levels of gelatinized brown flour. Brown flour gel addition significantly affected dough rheology and bread quality. Doughs made with gel required more water. Furthermore, significant interactions between gelatinized brown flour and water content were found for bread volume and crumb hardness. The second trial tested effects of gelatinized brown flour addition in doughs prepared with optimal water content (gelatinized flour samples required more water to reach optimum levels). Dough rheology was improved with the use of gelatinized brown flour; bread samples had significantly higher volume and lower hardness and chewiness. The addition of gelatinized brown flour may represent a good strategy to improve the baking performance of brown wheat flours, notably dough rheology and bread quality. The technique does not require the addition of new ingredients and preserves the high nutritional value of brown flour.
... This observation is related to the moisture content, which showed an increasing trend as more water roux starter was added to the bread (r 5 0.999 and P < 0.001). Gelatinized starch and gluten in the water roux starter played a key role for moisture content by holding more water than the regular starch (Sajilata et al. 2006;Yamauchi et al. 2014). Highly gelatinized dough in bread baking exhibits increased volume by keeping more gas and vapor on the pore walls (Therdthai et al. 2002;Tsai et al. 2012). ...
... Conversely, baking loss (r 5 0.940, P < 0.017) and moisture content (r 5 0.938, P 5 0.019) were negatively associated with the hardness of the samples. Moisture in the bread dough seemed to be less evaporated during baking because of the improved sustainability of the pore walls against gas pressure (Naito et al. 2005;Yamauchi et al. 2014). Gumminess and chewiness also showed similar decreasing patterns with significant differences across the samples (P < 0.05) as more water roux starter was used in the bread (Table 3). ...
The physicochemical characteristics, texture profiles and consumer acceptance of rice pan bread with various levels of water roux starter (Tangzhong) were investigated. Water roux starter (1.5–6.0%, flour base) was added to the bread dough. The bread samples containing water roux starter had significantly higher moisture contents and specific volumes (P < 0.05). Water roux starter results in the bread having lower hardness, gumminess and chewiness, but there was no significant difference in cohesiveness and springiness. The results of the consumer acceptance test showed that the subjects were split into two groups; one consumer group (52.3%) preferred the bread with 4.5% and 6.0% (flour base) of water roux starter, and the other group (47.7%) preferred the control sample. Adding water roux starter decreased hardness of the bread so that it met the more than 50% of consumers who preferred soft texture. The textural change by adding water roux starter showed positive consumer acceptance in the rice pan bread.
Texture of pan bread is one of key factor for bread quality. Additional ingredients such as glyceryl monostearate, various gums and/or methyl cellulose to make pan bread soft and glutinous are not necessary when water roux starter was applied in rice pan bread. Water roux starter can be applied to other bread making for baking soft and glutinous bread without any additional additives. In addition, water roux starter in the bread was effective in making same volume of bread with few amounts of ingredient, which is beneficial to bakery industry.
... Yamauchi et al. (2014) related the higher moisture and saccharide content of Yudane bread as a reflection of increased water absorption and decomposition of starch, resulting in a softer texture and slower staling.Dough and bread crumb structure The large and small starch granules detected in all dough treatments just after mixing and proofing were also observed byBlaszczak et al. (2004) in the microstructure of wheat dough. The interaction of gelatinized starch with the gluten network observed in Figs. ...
Sweet potato a nutritious and abundantly available food crop in many developing countries has been explored for baking to increase its use in food processing. Though it often results in lower quality bread it can be improved with enzyme treatments. Thus, this study evaluated the effect of purple sweet potato powder (PSPP) supplementation, and α-amylase (AM) and hemicellulase (HC) treatments on the texture and retrogradation during storage, and structure of bread. Results showed that PSPP supplementation gave rise to bread with higher firming rate related with greater starch-gluten interaction. On the other hand, AM and HC treatment resulted in lower firming rate, amylose content, enthalpy of retrogradation, rupture properties, and moisture loss during storage of PSPP supplemented bread. These improvements in texture properties and structure indicate more acceptable bread that may lead in increased utilization of purple sweet potato.
... The gelatinization temperature of rice flour with high damaged starch content is low (Naganuma 2003). In wheat flour bread, the starch gelatinization properties are related to specific loaf volumes in breads (Sandstedt 1961), and the gelatinized starch gel in bread dough lowers the breadmaking quality (Naito et al. 2005, Yamauchi et al. 2014. Therefore, it is speculated that the damaged starch in bread dough with rice flour creates a gel-like gelatinized starch that degrades the gluten network of bread dough with the rice flour. ...
The production of various rice flour-based food products such as bread, noodles, and cakes is expected to increase the consumption of rice and the utilization of rice paddies in Japan. This paper reviews studies conducted on the characteristics of rice flour and the rice cultivars suitable for the production of rice flour bread containing gluten. The challenges of reducing the cost of producing rice bread are also reviewed. The production of rice flour bread containing gluten of a highly specific loaf volume requires the use of rice flour with a low damaged starch content that can be produced by jet milling wet rice after water or enzyme treatment. The amylose content of rice flour affects the quality of bread, including its shape and hardness. Rice flour with an amylose content of 16% to 20% forms a chewy and moderately soft bread. When rice flour with a low damaged starch content (less than 5%) and a desirable amylose content (16% to 20%) is used, the production of rice flour bread containing gluten is easy without being different from how wheat flour bread is made. In order to reduce the cost of producing rice flour, high-yielding cultivars or a pin milling system using floury rice cultivars should be employed; high-yielding cultivars are now being used for the production of rice flour. With the pin milling system, rice flour belonging to the floury rice cultivar has a low damaged starch content. However, there is a need to develop a high-yield floury rice with reduced weight loss during polishing, as well as new polishing processes. Furthermore, the production of brown rice flour contributes to reducing the cost of producing rice flour because no polishing process is required. Brown rice flour with a low damaged starch content can be produced using a jet mill after soaking for more than 12 h. And given its favorable high nutritional properties, bread made from brown rice flour will prove appealing to consumers. Despite expectations of increasing of the consumption of rice through the use of rice flour as in the production of rice flour bread, the cost reduction of rice flour production and the development of delicious rice flour bread desired by consumers are still insufficient. By understanding the requirements of bread-making companies and obtaining a deeper knowledge about the quality characteristics of rice flour, such as amylose content and protein composition, the production of rice flour bread appealing to consumers can be expected.
... Post-thermal processing contamination is also possible (Chavan and Chavan, 2011). OFSP puree based bread also undergoes spoilage by staling which is the commonest spoilage in bread (Hiroaki et al., 2014). Bread staling involves modifications of the product matrix, both the macroscopic and the molecular structures. ...
Orange fleshed sweet potato (OFSP) puree has been promoted as a functional ingredient in bread with the overall aim of alleviating vitamin A deficiency (VAD). OFSP puree bread has been commercialized in many sub-Saharan Africa countries with over-reliance on the cold storage in its supply. However, this has resulted into higher costs to producers as it requires additional capital and lacks stability in the supply of the puree for production. The current study was designed with the overall objective of evaluating the use of shelf-storable OFSP puree as an alternative to the fresh OFSP puree in bread production. The study employed an experimental study design with factorial arrangement where two factors including different treatments of shelf-storable OFSP puree and periods of storage. OFSP puree sample was dosed with different combinations of chemical preservatives: treatment 1 with 0.5% potassium sorbate + 0.5% sodium benzoate + 1% citric acid and treatment 2 with 0.2% potassium sorbate + 0.2% sodium benzoate + 1% citric acid. Each of the treated puree was stored at ambient conditions for a period of four months. The OFSP purees were sampled monthly for analysis and incorporation into bread at 30% and 40%. Bread in which fresh OFSP puree incorporated at similar levels and wheat breads acted as controls. The nutritional composition of puree and bread, physical attributes and microbial stability of the breads were determined.
The results showed 45.6% and 57.3% reduction in β-carotene content in both treatment 1 and 2 of shelf-storable OFSP purees respectively by the fourth month (p<0.05). Bread samples made by incorporating 40% shelf-storable OFSP puree provided significant (p<0.05) levels of β-carotene to consumers up to three months of storage; treatment 2 shelf-storable OFSP bread provided up to 121.30 ±8.05 RAE. The crude ash and moisture contents of shelf-storable OFSP puree bread were significantly (p<0.05) higher than that of the control wheat bread. The proximate composition of bread made by incorporating puree sampled at different months did not differ significantly (p>0.05). The loaf weight, volume and specific volume of bread from shelf-storable and fresh OFSP purees as well as wheat bread were not significantly different (p>0.05).
The most acceptable breads was one in which 40% fresh OFSP puree was incorporated (p<0.05). The two treatments did not differ significantly (p>0.05) in acceptability of the breads when compared to wheat bread. The saltiness, smoothness, crumb colour and crust colour of shelf-storable OFSP puree bread was significantly higher (p<0.0.5) than the wheat bread but similar (p>0.05) to fresh puree bread. Microbial tests revealed that incorporation of OFSP puree, whether fresh or shelf-storable, into bread resulted into lower yeast and mold counts (p<0.05). Aerobic counts in shelf-storable OFSP puree bread increased with the period of storage of the OFSP puree (p<0.05). Shelf-storable OFSP puree bread could be stored for seven days with no visible yeast and mould spoilage. The current study found that shelf-storable OFSP puree, notwithstanding the level of preservatives, can be an alternative to fresh puree in the substitution of wheat flour with OFSP puree in bread production. Shelf-storable OFSP puree can therefore be promoted as an alternative to fresh OFSP puree in bread production.
... OFSP puree based bread also undergoes spoilage by staling which, is the commonest spoilage in bread 69 . Bread staling involves modifications of the product matrix, both the macroscopic and the molecular structures. ...
Bread though an exotic food product in sub-Saharan Africa, has been an important cereal product consumed by most individuals among the vast Sub-Saharan African population. Bread formulations in both the local and industrial production have evolved. The latest and emerging technology in bread formulation involve the incorporation of orange-fleshed sweetpotato (OFSP) puree. OFSP puree-based bread is commercially available across sub-Saharan Africa (SSA) and is being promoted due to the potential nutritional benefits that it possesses. Together with OFSP flour based bread, OFSP puree based bread serves as a good food vehicle for β-carotene; this serves to alleviate vitamin A deficiency (VAD) especially among the vulnerable population in SSA. The production of OFSP puree based bread has so far been relying on fresh OFSP puree or cold-chain stored OFSP puree. However, this has presented economic challenges and problems to the sustainability and expansion in OFSP puree bread production. Cold chain stored OFSP puree is capital intensive and has inconsistent supply. With the development of shelf-storable preservative treated OFSP puree, most of these challenges will be overcome without undoing the currently harnessed benefits. The use of OFSP puree in bread baking can then be expanded easily at minimal production costs and maximum retention of nutritional quality. Therefore, the use of the shelf-storable OFSP puree in bread baking needs to be evaluated further to present a substantiated case for its use. The current review has been developed with focus on the scientific advances in the production of OFSP puree based bread from both historical and a forecast perspective. The scientific progress and breakthroughs in the use of OFSP puree in bread are critically reviewed.
... The higher DS content of dough without the enzymes can be associated with the amounts of DS generated due to the physical damages during the milling process. Excess amount of DS cause undesirable effects on BMQ (Santiago et al. 2015a;Yamauchi et al. 2014). WWF ? ...
The functional ingredients in whole wheat flour, such as dietary fiber, vitamins, and minerals, have beneficial health effects. However, the excessive amount of dietary fiber in whole wheat flour inhibits gluten network formation and diminishes bread making qualities (BMQ). Adding appropriate amounts of enzymes, α-amylase (AM) and hemicellulase (HC), could be a solution to these problems. In this study, response surface methodology (RSM) created a response surface model and Solver (Excel add-in software) calculated the optimal amounts of the enzymes. Adding optimum concentrations of AM and HC drastically improved BMQ (gas retention of dough, specific loaf volume, and bread staling) of whole wheat flour dough and bread compared to whole wheat flour dough and bread without the enzymes. These results showed that combining RSM and Solver was an effective and reasonably easy method that determines optimal concentrations of enzymes to obtain the highest quality bread using whole wheat flour.
... The protein and ash contents were 12.2 and 0.39 % (w/w, 13.5 % moisture base), respectively. These contents were measured according to the methods reported by Yamauchi et al. (2014). Special grade reagents, L (+) -ascorbic acid (ASA) and reduced glutathione (GSH), were purchased from FUJIFILM Wako Pure Chemical Corporation (Tokyo, Japan) and used as oxidizing and reducing reagents of dough, respectively. ...
The physical properties of dough (PPD), instantaneous elasticity, regularity coefficient of viscosity, and relaxation time (τ0), of various white bread doughs without yeast addition were measured by the creep method based on a Maxwell-2-element model (Maxwell model). It was assumed that PPD do not change during fermentation and thus the stress of various doughs in the proofing process could be obtained using Euler's method. Simulation results revealed that dough with large elastic characteristics, a large τ0, and fermented quickly had a high stress peak during the expansion process and that the final stress (σend) also had a high value compared to other doughs. Meanwhile, dough characterized by a small τ0 and slow fermentation showed the opposite tendency. Additionally, the calculated σend was significantly correlated with the gas retention of dough and specific loaf volume (SLV). These results demonstrated that SLV of various white bread doughs could be estimated using PPD and fermentation speed.
... The obtained grain samples to which water was added so as to make their moisture content 16% were milled with a Bühler test mill (Bühler Inc., Uzwil, Switzerland) and flours of 60% extraction rate (flours) were obtained. The protein and ash contents (w/w, 13.5% moisture base) were respectively measured using a near-infrared reflectance instrument (Inframatic 8120, PerCon Co., Hamburg, Germany) and the method of the American Association of Cereal Chemists (AACC) as reported by Yamauchi et al. (2014). ...
The physical properties of various white bread doughs made from the flours of ‘Harunoakebono’ and 10 genotypes of its near-isogenic lines with different compositions of high molecular weight glutenin subunit (HMWGs) were measured with the Creep method based on a Maxwell–2–element model. The expansion stress in the proofing process of various doughs was obtained by a numerical calculation method. The results indicated that doughs with high elastic characteristics, namely large relaxation time (τ0) and regularity coefficient of viscosity (ηN), have high dough stress throughout the proofing process and high stress at the proofing end (σend) and conversely, the low elastic dough with the small τ0 and ηN has the completely opposite tendency. This study also showed that there are significantly high correlations between the calculated σend and bread-making quality (BMQ) such as gas retention of dough and specific loaf volume (SLV). These results showed that BMQ, represented by SLV, of various white bread doughs were greatly influenced by the dough’s physical properties, especially τ0 and ηN, which change with differences in the compositions of the HMWGs.
The objective of this study was to find the possibility of hydrostatic pressure treatment (50 MPa, 30°C), and carbon dioxide treatment (1.0 MPa, 40°C). Yudane method uses a dough made by mixing boiling water and flour in addition to those by water. Advantages of this method are unique texture and sugar sweetness generated by endogenous enzymes. On the other hand, by endogenous enzymatic reaction under bacteriostatic pressure, it will be possible to improve the taste as well as Yudane method. By the pressure treatments the increases of reducing sugar, glutamic acid and water-soluble protein were observed and the decreases of gliadin and glutenin were characterized. From the increases of total sugars and amino acids, improvement of taste, fragrant bread crust and promotion of yeast activity can be expected.
This study aimed to reveal the bolus characteristics of high-moisture content bread made by adding a starch paste, consisting of pregelatinized wheat starch and water. The addition of starch paste increased the crumb moisture, thereby reducing hardness and increasing cohesiveness. In the sensory evaluation, 60% starch paste-added bread (52.6% moisture) was judged to be easier to swallow than the control bread (42.7% moisture). The hardness and adhesiveness of a simulated bolus made with crushed crumb and artificial saliva were reduced with the addition of increasing amounts of starch paste, a trend which became more prominent when α-amylase was added to the artificial saliva. The degree of gelatinization of starch paste-added bread was also higher than that of control bread. These results revealed that high-moisture content bread with a starch paste ratio of 60% or higher was easy to swallow, since the highly gelatinized bolus was easily hydrolyzed by α-amylase during chewing.
This study aimed to investigate the effect of heated gluten on the bread-making qualities of Yudane dough. Yudane is a type of bread dough made by mixing boiling water with flour. Various bread-making tests were performed using non-heated wheat starch and heated freeze-dried gluten, which was used to imitate Yudane dough. The imitation Yudane dough was prepared by mixing heated gluten (prepared by heating a mixture of freeze-dried gluten and water from 55 to 80 degrees C in increments of 5 degrees C) with non-heated wheat starch. The imitation Yudane dough was then added to flour dough at 20% (w/w, flour base). Compared with the control dough (without heated gluten), the dough mixed with imitation Yudane dough (with heated gluten) had longer dough development time, and higher gas retention and specific loaf volume. These improvements in bread-making quality were mainly related to the partially denatured gluten present in the imitation Yudane dough. In addition, the bread made with imitation Yudane dough (including denatured gluten) showed a slow staling rate, attributable to the increased molecular weight of the heated gluten compared to the native gluten.
A method for investigating the mechanical properties of bread crumb has been established in previous studies. However, there are few reports describing the effects of using whole wheat flour and the addition of enzymes (α-amylase and hemicellulase) on the mechanical properties of bread crumb during storage. Therefore, in this study, we investigated the effects of storage on the properties of the following bread crumbs: 1) made from white wheat flour as a control (C), 2) white flour combined with whole wheat flour (W) at a final ratio of 3:2 white to whole wheat flour (C＋W), and 3) C＋W with enzymes (E) added at optimal concentrations (C＋W＋E) using pullman scale bread making. Rupture force, rupture deformation and rupture energy were decreased using W, as the higher amount of insoluble dietary fiber in whole wheat flour disturbs the fine gluten network formation in dough, resulting in a weakened bread crumb structure. In comparison, C＋W＋E had a lower rupture force, a higher rupture deformation and lower viscoelastic values compared with both C and C＋W, since α-amylase and hemicellulase digest damaged starch, insoluble dietary fibers and gelatinized starch, which decrease bread making quality, during bread making, resulting in improved bread crumb texture. This study elucidated the effects of using W and the addition of E on the mechanical properties of bread crumb during storage. The addition of E made it possible to obtain high quality pullman bread using W.
This study aimed to investigate the effects of gelatinized starch on the bread-making qualities of Yudane dough. Yudane is a type of bread dough made by mixing boiling water with flour. Various bread-making tests were performed using freeze-dried gluten and heated and gelatinized wheat starch, which was used to imitate Yudane dough. The imitation Yudane dough was prepared by mixing gelatinized starch, prepared by heating a mixture of wheat starch and water from 55 to 80°C in increments of 5°C, with freeze-dried gluten. The heat treatments partially or completely gelatinized the wheat starch in the imitation Yudane dough. The imitation Yudane dough was then added to flour dough at 20% (w/w, flour base). Compared with the control dough (without Yudane), the dough mixed with Yudane dough had lower gassing power, gas retention, and specific loaf volume. These significant reductions in bread-making quality were mainly related to the inhibition of gluten network formation during dough mixing by the gelatinized wheat starch present in the imitation Yudane dough. In addition, the bread made with imitation Yudane dough (gelatinized wheat starch) showed dark-brown crust, caving, a slow staling rate, as well as the major features of bread made by the normal Yudane bread-making method.
The effect on bread-making quality of the addition of sourdough fermented by Leuconostoc citreum YMC08 strain (YMC08) was evaluated. Two kinds of sourdough were prepared by mixing flour, sterilized water and YMC08 with or without sucrose. The addition of sourdough to bread dough increased not only the specific volume and softness of the bread, but also the amount of organic acids and total free amino acids compared to without sourdough addition. These increases were more pronounced in breads containing sourdough prepared by adding sucrose (LCS) than in those containing sourdough prepared without adding sucrose (LC). The difference between LC and LCS may depend on the increase of gassing power of dough and/or dextran production by YMC08. In addition, the contents of saccharides and acetic acid in LCS significantly decreased and increased, respectively, compared with those in LC. These were caused by sucrose addition at the time of sourdough preparation, which might affect the metabolism of saccharides and organic acids by lactic acid bacteria.
Thermal properties of wheat proteins were studied by differential scanning calorimetry (DSC). In order to assess the endothermic peaks, protein samples were heated with different water contents. At very low water content it was possible to register the protein endotherms at 50C for albumins and globulins, and 58C for gliadins, whereas two endothermic peaks at 64 and 84C were assigned to glutenins. The enthalpies of the protein transitions were very small for albumins, globulins, and gliadins, but high enthalpies (11.47 and 14.43J/g) were obtained in the case of glutenins, suggesting a more ordered structure of these proteins. Reversibility of the glutenin denaturation was demonstrated by DSC; the successive heating-cooling cycles showed a shift in the endotherm peaks to higher temperatures and also higher enthalpies were required after each cycle.
We developed a modified expansion test under low pressure for simple estimation of breadmaking quality (specific loaf volume). The expansion volume was highly correlated with specific loaf volume (r=0.849). This correlation coefficient was significantly higher than those derived from protein content and SDS sedimentation volume at the one side 1% level. Our new testing method will be useful to evaluate the exact breadmaking quality of breeding lines at early breeding stage.
The effects of adding gelatinized starches to a kneading dough (a process known as yukone in Japanese) on the crumb grain of baked white breads were studied using magnetic resonance imaging (MRI) and using scanning electron microscopy (SEM) with and without distilled-water soaking of the samples. MRI revealed that pores became larger and rounder in yukone breads compared to control breads using the sponge dough method, while the number of pores decreased in yukone breads. SEM revealed many starch granules on the surface of pore walls in the control breads, whereas the yukone breads contained starch gels cemented between starch granules. Gluten nets were found to be uniform and oriented in the control breads and became thicker and coarser in the yukone breads. Comparing the SEM images of two commercial white breads made by the yukone method, the fine gluten nets under the starch walls were found to be considerably different.
The bread-making quality of flour made from two new Japanese bread wheat varieties, Haruyokoi and
Kitanokaori, was evaluated, and the staling and texture of bread made from these flour types were
compared with those of flour made from representative bread wheat classes, No.+ Canada western red
spring (+CW) and Hard red winter (HRW). There was not a large di#erence in the bread-making quality of
the above four flour types, except that the water absorption of the Kitanokaori flour was high, and the
gassing power of the dough was low. Bread made from the two above-mentioned Japanese flour types (two
new bread varieties) were quite soft after baking, and the degree of staling (changes in hardness) were
somewhat lower than those made with +CW and HRW. The cohesiveness of the two new bread varieties, i.
e., the index of bread elasticity, showed higher values than those of others up to + day of storage. From the
analysis of bread staling and the retrogradation of starch in bread, it was proven that the staling rate and
starch retrogradation rate constants of the two new bread varieties were approximately the same as those
of bread made from +CW and HRW but the starch retrogradation of the new bread varieties was somewhat
slower than that of the others up to , days of storage. The analysis of hardness and cohesiveness of the
flour and starch gel from the above four flour types indicated that the softness and high cohesiveness of the
two new bread varieties after baking were, to a great extent, the result of the soft texture of starch gel in
these varieties. These results showed that the somewhat slow staling, especially staling in the early stage,
and the extreme softness after baking of the two new bread varieties were attributed to the soft texture and
low retrogradation of starch gel in the bread, which was related to the lower amylose content of these new
A Japanese domestic middle-soft flour (Hokusin) was mixed with an extra strong (ES) flour (Wildcat) and examined to evaluate its quality for bread-making. The results were as follows: (1) The properties of the dough of the mixed flour such as the mixing, physical and gas retention properties were similar to the commercial foreign hard flour called Camellia. (2) The baking quality, mainly the specific loaf volume and crumb grain, of the bread from Hokushin-Wildcat blend was similar or superior to Camellia except for the color of the crumb and the staling of the bread. (3) The bread from the 50% Wildcat blend staled a little faster, and the specific loaf volume and crumb grain was better than Camellia. The slightly rapid staling of this bread was attributed to the retrogradation rate of the starch, which was somewhat higher than that in Camellia. (4) The retrogradation of starch in the bread from the 50% Wildcat blend was a little faster than Camellia because of the lower water content of the bread due to the slightly less absorbed water of this flour.
The bread-making quality of rice flour was evaluated by conducting baking tests using strong wheat flours blended with various quantities of rice flour containing 15% gluten (rice flour). The dough properties and bread qualities obtained from these blends were analyzed. The characteristics of dough and bread changed according to the increase in the blended percentage of rice flour used. The water absorption of blends increased rapidly and the Farinograph characteristics were similar to those of weak flour in that the dough became less pliable and more fragile. The gas retention properties of the dough evaluated using the vacuum expansion method and gassing power after 2 h of fermentation decreased greatly. The appearance and crumb grain of the bread became rough, and the specific loaf volume (SLV) decreased. The upper crust was slightly reddish white, and the crumb grain was somewhat dusty. The sugar and amino acid contents in the bread decreased and the amount of maltose, glutamate, glycine, alanine, and phenylalanine decreased drastically. The texture of the bread was very soft at first, however, the bread rapidly hardened when stored. During the storage, the bread had high cohesiveness and showed high recovery when compressed.
Cereal Chem. 72(3):320-325 The change of the moisture profile within a bread loaf and bread texture ena involved in the process. To evaluate bread staling, the stress-strain during storage up to 300 hr at 250 C were investigated. Three different behavior of bread during aging was investigated. By considering the types of bread were considered: 1) bread from straight dough using conven- moisture profile within the bread loaf, a correlation between local moisture tional baker's yeast fermentation; 2) one-stage sour-dough bread from content and texture of stale bread was found. The experimental results starter culture of Lactobacillus brevis; and 3) bread from straight dough proved that, to prevent staling, it is more important to slow down the acidified with lactic acid. An attempt to correlate bread-staling kinetics dehydration phenomena rather than it is to increase the initial moisture to water migration was made by considering the mass transport phenom- content in the bread.
Recent reports suggest that dextrins produced by anti-stalingalpha-amylases are directly involved in retarding the staling process. We report experiments that test this hypothesis using a new method of dextrin extraction at 90° C in the presence of papain. Various dextrins were added to standard bread and extracted under a variety of conditions. No change in staling rate was observed, but, in most cases, there was little difference between the level of dextrins extracted from baked loaves and that from the control loaves, confirming that added dextrins are hydrolysed by native flour amylases. Adding a bacterialalpha-amylase of intermediate temperature stability (Novamyl) or a fungal glucoamylase of intermediate temperature stability (GA300N) oralpha-amylase plus glucoamylase to the dough, produced loaves with different dextrin profiles. Measured staling rates did not relate to the presence of dextrins in a specific size class. It appears that dextrins present in an amylase-treated loaf are symptomatic of a modification to the starch that retards staling, but are not the direct cause of the anti-staling effect.
The quantitative relationships between loaf specific volume and the rate and extent of staling in bread as measured by changes in crumb elastic modulus have been examined. The results show that loaf specific volume is a major factor in determining both the rate and extent of staling, both of which decrease in a linear manner, over the range studied, as loaf volume increases. Only two factors have been found that have a significant influence on these curves, the basic breadmaking process and the storage temperature. The influence of changes in loaf specific volume on staling characteristics is greater in bread prepared by bulk fermentation than in bread prepared by the Chorleywood Bread Process. Bread made by the Chorleywood Bread Process stales less rapidly than bread made by the conventional bulk fermentation process. The effect of loaf specific volume on the rate of staling is more marked as the storage temperature is lowered.
!-Amylases, usually added to bread recipes as anti-firming agents, are known to produce low molecular weight dextrins by starch hydrolysis. The influence of these compounds on the gelatinization and retrogradation of starch was studied by differential scanning calorimetry. Adding oligosaccharides to starch caused a delay in gelatinization, although its extent was not quantified. However, oligosaccharides of degrees of polymerization (DP) 3-5 reduced the enthalpy of the retrogradation endotherm, shown as the staling endotherm. The addition of gluten to starch and starch/oligosaccharide mixtures had no effect on the gelatinization and retrogradation of starch. The retrogradation of starch in dough samples was also analysed, after 'baking' in the calorimeter, to obtain additional information about starch retrogradation during storage. Oligosaccharides of DP 3-5 also reduced the enthalpy of the retrogradation endotherm. This work provides evidence that oligosaccharides influence starch changes during the baking and storage of bread. These effects could be considered as the mechanism by which the bacterial !-amylase reduces starch retrogradation and acts as an anti-firming agent.
Bread crumb X-ray patterns were analysed by different methods, the objective being to provide more in-depth knowledge of the relationships among starch crystallinity, amylopectin retrogradation and bread firming. Both crumb-firming and amylopectin retrogradation increased with storage time. However, total mass crystallinity grade and relative crystallinity increased only in the first 24h. The determination of starch crystallinity requires the separation of the crystalline and amorphous intensities, which is sometimes arbitrary, so it would be useful to improve this methodology. Different methods used to determine total crystallinity grade only show the differences existing between fresh and stored bread. B-type crystal structure—corresponding to the amylopectin retrogradation—increased during bread storage, showing a high correlation with bread-firming and storage time. This fact emphasized the above results and suggested that amylopectin retrogradation is an important component to the elucidation of bread staling.
Potato starches with various contents of amylose from the Eniwa, Benimaru, and Norin No. 1 cultivars were blended with wheat flour at 10 to 50% potato starch (on a weight basis), and differential scanning calorimetry (DSC) studies were then conducted to determine if there were any traces of starch at 30% wt suspension. The amylose content of Eniwa potato starch was higher than those of the Benimaru and Norin No. 1 potato starches. Eniwa potato starch also exhibited significantly higher DSC traces than the Benimaru and Norin No. 1 potato starches. The DSC traces of the gelatinization peak temperature (TP) of the Eniwa potato starch–wheat flour mixture remained almost identical up to 30% and then showed a tendency to decrease from 40% potato starch in the mixtures due to significant dilution of wheat flour by potato starches at 40 and 50%. However, the TP values of the Eniwa potato starch–wheat flour mixture were significantly higher than those of the Benimaru potato starch–wheat flour and Norin No. 1 potato starch–wheat flour mixtures, and exhibited a trailing shoulder up to 40% Eniwa potato starch. On the other hand, no trailing shoulder was evident at 50% Eniwa potato starch in the mixture or in the Benimaru and Norin No. 1 potato starch–wheat flour mixtures. Such phenomena occurred due to the smaller differences in the TP of the control wheat flour, Benimaru and Norin No. 1 potato starches. The TP of the mixtures was slightly higher than that of the control samples due to the influences of the wheat gluten in the mixtures.
Six kinds of dextrins (DE, dextrose equivalent; 3–40) were substituted for wheat flour up to 20%, and physicochemical properties of dough and quality of bread were examined. At 2.5% substitution, gelatinization and viscoelastic properties of dough did not significantly differ between the control (100% wheat flour) and the substituted samples. Likewise, firmness of crumbs baked with dextrin at 2.5% did not have significant difference during storage. Breads baked with dextrins (DE 19–40) showed less staling endothermic enthalpy than those with DE 8 or 11 at 2.5% of substitution. A large amount of substitution, such as 15% or 20%, could not form suitable dough properties and bread quality. Δaw of crumbs baked with various lengths of dextrin did not significantly differ at 2.5% of substitution. As a result, lower molecular dextrins (DE 19, 25 and 40) at 2.5% of substitution retarded retrogradation of starch in crumbs during storage than higher dextrins (DE 3 and 8). However, this retrogradation was not accompanied by the softness of crumb.
The crystallinity of starch in crispy bread crust was quantified using several different techniques. Confocal scanning laser microscopy (CSLM) demonstrated the presence of granular starch in the crust and remnants of granules when moving towards the crumb. Differential scanning calorimetry (DSC) showed an endothermic transition at 70 °C associated with the melting of crystalline amylopectin. The relative starch crystallinity, as determined by X-ray and DSC, from different types of breads was found to lie between 36% and 41% (X-ray) and between 32% and 43% (DSC) for fresh bread crust. Storage of breads in a closed box (22 °C) for up to 20 days showed an increase in crust crystallinity due to amylopectin retrogradation both by X-ray and DSC. However, DSC thermograms of 1-day old bread crust showed no amylopectin retrogradation and after 2 days storage, amylopectin retrogradation in the crust was hardly detectable. 13C CP MAS NMR was used to characterize the physical state of starch in flour and bread crumb and crust. The intensity of the peaks showed a dependence on the degree of starch gelatinization.Comparison of the results for two different types of bread showed that the baking process influenced the extent of starch crystallinity in the bread crust. Amylopectin retrogradation, which is the main process responsible for the staling of bread crumb, cannot be responsible for crispness deterioration of the crust as amylopectin retrogradation upon storage of breads could only be measured in the crust after 2 days storage. Under the same conditions loss of bread crust crispness proceeds over shorter times.
Simple sugars, oligosaccharides, polysaccharides, and their derivatives, including the methyl ethers with free or potentially free reducing groups, give an orange-yellow color when treated with phenol and concentrated sulfuric acid. The reaction is sensitive and the color is stable. By use of this phenol-sulfuric acid reaction, a method has been developed to determine submicro amounts of sugars and related substances. In conjunction with paper partition chromatography the method is useful for the determination of the composition of polysaccharides and their methyl derivatives.
The glass-transition behaviour of four hydrated wheat gluten proteins (alpha-gliadin, gamma-gliadin, omega-gliadin and high-molecular-weight (HMW) subunits of glutenin) was studied using differential scanning calorimetry (DSC). By fitting the data to the Gordon-Taylor equation, which has previously been used to describe the plasticization of polymers by diluents, the glass-transition temperatures (Tg) for the dry proteins were found by extrapolation. The values for Tg were within the range 397-418 K. Values for the heat capacity increment delta Cp at Tg for the plasticized proteins were also determined and ranged from 0.29-0.47 J g-1 K-1 with no dependence on water content. The differences in glass-transition behaviour of the proteins are discussed in relation to their secondary structure.
The glass transition temperature (T(g)) of hydrophobized and native wheat gluten and its protein fractions, with water mass fraction from 0 to 0.2, was studied using modulated differential scanning calorimetry. The T(g) values of unplasticized products were approximately 175 degrees C whatever the treatment (hydrophobization) or the fraction tested, except for the gliadin-rich fraction (162 degrees C). Experimental change in heat capacity at the glass transition (DeltaC(p)) ranged from 0.32 to 0. 50 J/g/ degrees C depending on the gluten fractions. The Gordon-Taylor fit of T(g) evolution as a function of water content showed that glutenin-rich fractions were more sensitive to water plasticization than the gliadin-rich fraction. The Kwei equation gave better fit to experimental data and demonstrated that the water plasticization of gluten and its fractions is influenced by secondary interactions. However, the application of the Couchman-Karasz equation without fitting predicts satisfactorily the plasticization of gluten proteins by water.
The influence of enzyme mixtures containing amylase and lipase activities on straight dough bread staling was studied. Amylopectin retrogradation, crumb firming, amylose-lipid complexes, and dextrin production were analyzed in bread samples supplemented with two enzyme mixtures. The addition of enzyme mixtures to bread formula causes a beneficial effect on bread keeping properties and the formation of a more thermostable amylose-lipid complex than the one found in control bread. Amylopectin retrogradation was inhibited by the use of the enzyme; the effect was accompanied by reduced crumb-firming rates. The enzymatically generated water-soluble dextrins (maltose and DP3, DP4, DP5, and DP6 dextrins) are the most effective in preserving crumb softness during bread storage.
The firming and carbohydrate fractions of concentrated starch gels supplemented with four alpha-amylases from different sources were evaluated. Correlations were found between the firmness data and results for the carbohydrate fractions extracted from the gels. The thermostable (TBA) and intermediate temperature stability (ISBA) bacterial alpha-amylases were most effective in decreasing the rate of firming. The cereal alpha-amylase at the high level (CAH) was also effective. The CAH produced the largest quantity of dextrins at storage time zero and the thermostable bacterial alpha-amylase at the high level (TBAH) after storage for 5 days. None of the maltooligosaccharides appeared to be responsible for the decreased rate of firming of the gels. The results indicated that the TBA and ISBA most effectively inhibited firming because they degraded the external branches and the intercluster regions of amylopectin during storage. Consideration of previously reported differential scanning calorimetry and X-ray crystallography results leads to the conclusion that the antifirming action of the TBA and ISBA is due to their ability to degrade the amylopectin and amorphous regions of the gels during storage, which inhibits the formation of double helices and decreases the strength of the starch gel matrix. Gels supplemented with the TBA and ISBA were most crystalline but firmed to a lesser extent. These results are similar to those previously reported by other researchers for bread and strongly suggest that starch retrogradation plays a primary role in bread staling.
Concentrated starch gels were supplemented with four alpha-amylases from different sources. The retrogradation and recrystallization of the gels were evaluated using differential scanning calorimetry (DSC) and X-ray crystallography. Correlations between the retrogradation data and the carbohydrate fractions extracted from these gels were determined. The thermostable (TBA) and intermediate temperature stability (ISBA) bacterial alpha-amylases were most effective in decreasing the rate of retrogradation of the starch in the gels. The cereal alpha-amylase at the high level (CAH) was also effective. Supplementation with the alpha-amylases increased the crystallinity of the gels. Gels supplemented with TBA or ISBA were most crystalline and retrograded to a lesser extent. The results indicated that DSC gives not only a measure of recrystallized amylopectin but also a measure of total order (recrystallized amylopectin and double-helical content). The maltooligosaccharides produced by the enzymes did not appear to be responsible for the reduced rates of retrogradation, but they appeared to be an expression of the degree of starch modification that was responsible for the inhibition of retrogradation. The crystallinity and retrogradation data were similar to results reported for bread and strongly suggest that bread staling is caused by the retrogradation of starch. The results also indicate that alpha-amylases decrease the rate and extent of retrogradation of starch gels by inhibiting the formation of double helices.
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