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The contribution of starch granules to the baking properties of frozen dough bread has been investigated using reconstituted dough method. The baking and aging characteristics of frozen dough bread were studied by texture analyzer, colorimeter, DSC, FTIR and LF-NMR. Results showed that starch had more impact on bread than gluten in specific volume of frozen dough bread, while gluten contributed more in color and cell density of frozen dough bread crumb during 8-weeks frozen storage. The changes of hardness mainly contributed to starch deterioration in first 4 weeks, then it was dominated by gluten in the later 4–8 weeks. A-Type granules have more effect on texture properties, number of cells and enthalpy of frozen dough bread during storage. B-Type granules contributed more on the size of cells in bread. The main aging change of wheat starch in profiles of bread was provided by A-Type granules during frozen storage. [Display omitted] • Wheat starch affect more on specific volume while gluten controls cell density of bread. • The hardness of frozen dough bread is determined by starch in early stage then by gluten. • A-Type granules affect the number of cells in bread, B-Type granule affect the size in them. • ●The main staling change of wheat starch in bread was provided by A-Type granules. [ABSTRACT FROM AUTHOR]

Effect of yolk plasma and granules on the properties of dough and bread was investigated by using the control bread without shortening. The separate addition of shortening, yolk, plasma all improved the height and cell density of bread, and the yolk gave the maximum elevation. Any samples did not affect the gassing power of dough. For dough properties, the addition of yolk and plasma resulted in larger final dough expansion volume, longer rupture time, larger resistance, elastic modulus, and yield stress. Shortening increased the dough extension and decreased the elastic modulus and yield stress. The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis indicated that some apoproteins in low-density lipoproteins from plasma were bound to glutenin to fortify the strength of gluten network in dough. Thus, yolk, especially apolipoprotein from plasma fraction, could improve the bread quality-height and hardness. Image 1 • Yolk and its plasma fraction elevated height of bread and softened initial crumb as a replacer of shortening. • Yolk and plasma improved cell density and mean cell area of crumb. • Yolk and plasma increased dough resistance, elasticity and gas retention capacity. • Apoprotein in low-density lipoprotein from plasma was bound to glutenin in dough. [ABSTRACT FROM AUTHOR]

Effect of pigskin-originated gelatin on dough properties and bread characteristics, especially on bread staling was investigated in terms of starch retrogradation and water migration in the present study. Results showed that gelatin significantly improved bread qualities during storage. Compared with the control, 7-day staling rate of bread containing 0.5% and 1.0% gelatin decreased by 6.56% and 20.83% respectively, indicating gelatin retarded the staling process of bread. This retardation effect was related to starch retrogradation and water migration. The relative crystallinity decreased from 15.12%, 11.60% to 10.75%, which demonstrated the alleviation effect of amylopectin crystallization. Bread samples containing 1.0% gelatin had the lowest retrogradation enthalpy of 2.93 ± 0.24 J/g followed by 0.5% gelatin bread and the control group, further indicating that gelatin may induce less water available to form crystal lattice and restrict the migration of starch molecules. The 5-day moisture loss rate for the control group was highest with the values of 12.39%, which was 1.43% and 1.83% higher than that of bread with 0.5% gelatin and 1.0% gelatin, respectively. Water activity and T 2 relaxation results provided the information that gelatin inhibited water migration upon storage and gelatin interacted with bread components. However, the effect of gelatin on improving bread quality and retarding staling could not be reflected by the dough properties measured through farinograph, extensograph and rheometer. This study suggested gelatin from pigskin had great potential to be served as an effective bread improver. Image 1 • Gelatin enhanced the bread qualities significantly, especially retarding the staling process. • Gelatin hindered the chain reassociation of starch molecules during storage. • Gelatin interacted with bread components and restricted water transfer. • Dough properties showed gelatin might to some extent weaken the gluten network. [ABSTRACT FROM AUTHOR]

Highlights • The acidified bread showed higher volume, lower moisture content and lower hardness. • Gluten network weakened and yeast activity enhanced in chemical acidified doughs. • Proteins and starches in acidified doughs showed varying degrees of hydrolysis. • Hydrolysis of proteins and starches mainly occurred after dough mixing. • Proteolysis and amylolysis basically depended on types of organic acids. Abstract This study aimed to improve the bread quality by adding acetic acid, lactic acid, malic acid, fumaric acid and citric acid to its ingredients. The underlying mechanism was explored through the changes in the yeast activity, proteolysis and amylolysis. All organic acids gave bread a higher specific volume, a lower moisture content, a lower pH value and a decreased hardness. Moreover, the yeast activity was enhanced, whereas the gas retention capability decreased in acidified doughs. Organic acids also reduced the molecular weight of proteins and starches, which led to the increase of NH 2 , free SH and reducing sugar contents. These changes were the most significant in the dough with 0.3% fumaric acid. Proteolysis and amylolysis mainly occurred after dough mixing and depended on the types of acids present in the mixture. Nevertheless, the cleavage of disulfide bonds in gluten might rest with the H+ concentration in the dough system. [ABSTRACT FROM AUTHOR]

Hen egg is commonly used in some cereal-based food, including cakes and bread. Ovalbumin, one of the major components of egg white protein, can affect the performance of the food product. The interaction between ovalbumin and gluten protein and its effect on property of dough and quality of Chinese steamed bread was investigated in this study. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) patterns indicated that ovalbumin was surprisingly not incorporated in glutenins by covalent bond, whereas size-exclusion high-performance liquid chromatography showed that glutenin macropolymer content in glutenins increased slightly. Furthermore, dynamic rheology experiments indicated ovalbumin led to a decrease in G ′ and G″ of dough. Based on molecular dynamic simulation and SDS-PAGE results, it was inferred that ovalbumin was not hydrolyzed by endopeptidases during dough fermentation and crosslinked to gluten proteins during steaming. Finally, ovalbumin improved maximum dough height (Hm) during dough development and specific volume of Chinese steamed bread. [ABSTRACT FROM AUTHOR]

The magnetic field is an emerging physical method used for food preservation, characterized by its high penetrability in food materials. The effect of a static magnetic field (MF, 2 mT) on frozen dough upon freeze-thaw treatments (3, 7, and 10 cycles) was investigated, with conventional freeze-thaw (CF) treatments being used as control. Results showed that the magnetic field ensured the baked bread made from dough a 17.59% larger specific volume and a 30.87% smaller crumb hardness. It accelerated the time for the dough to pass through the maximum ice crystal formation zone by 7 min and reduced the ice melting enthalpy from 63.55 J/g to 56.67 J/g after 10 freeze-thaw cycles. Nuclear magnetic resonance analysis suggested that the conversion of bound water to immobilized water and free water was inhibited. The yeast viability and activity were also better maintained, precisely as the observed increase of 18.18% and 42.23% in its survival and gassing power. After 10 freeze-thaw cycles, the free disulfide (SH) content was determined to be 1.642 μmol/g for CF doughs and 1.624 μmol/g for MF ones, respectively. A reduction of 24.26% in glutenin macropolymer depolymerization was achieved, indicated a more stable gluten structure under the magnetic field. [Display omitted] • Magnetic field improved the quality of frozen dough bread. • Lower depolymerization degree was detected in gluten using magnetic field. • Yeast survival and gassing power were better preserved under magnetic field. • Magnetic field inhibited water migrations and status change. [ABSTRACT FROM AUTHOR]

Reduced glutathione (GSH), released from lysed yeast cells, is well-known for weakening dough structure. However, its influence on bread texture and staling has not yet been completely elucidated. Herein, this study aims at assessing the effects of GSH on dough properties and bread quality, especially bread staling, using Rheofermentometer analysis, texture profile analysis (TPA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and low-field nuclear magnetic resonance (LF-NMR). The results revealed that GSH substantially decreased the dough height and gas-retention capacity during fermentation. The weakened dough structure was attributed to GSH-induced disulfide bond cleavage in gluten proteins and the depolymerization of glutenin polymers. The addition of 0.005%–0.01% GSH resulted in acceptable bread quality. However, bread supplemented with 0.015%–0.03% of GSH exhibited a coarser and more open crumb microstructure, as well as high level of hardness and low resilience during aging. GSH promoted crumb water loss and drove the water shift from the immobilized to the bound state. The DSC and XRD analyses further confirmed that GSH promoted starch retrogradation and recrystallization. These results suggest that apart from the gluten structure, GSH also altered gluten−starch interactions and water redistribution, ultimately decreasing bread quality and accelerating bread staling. Image 1 • Glutathione depolymerized protein and weakened gas retention capacity. • Glutathione decreased loaf volume and bread resilience, and increased hardness. • Moisture content decreased and water became less mobile with glutathione. • A coarser porous bread crumb was obtained in the presence of glutathione. • Bread staling rate was significantly increased in the presence of glutathione. [ABSTRACT FROM AUTHOR]