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Zein exhibited viscoelastic properties similar to those of wheat dough under appropriate conditions. To improve the characteristics of zein in wheat dough, wheat doughs with added zein (3%) were prepared under redox, salt, and acidic conditions. The incorporation of glutathione (GSH) into the zein-added dough (MGFZ) resulted in reduced viscoelasticity and increased creep strain, corresponding to a more relaxed water distribution, similar to what has been reported in wheat dough. In contrast, the salt-added dough exhibited the opposite trend, with a recovery rate reaching 70.11%. Azodicarbonamide (ADA) and acidic conditions showed a tendency to increase the viscoelasticity of MGFZ. Size exclusion high-performance liquid chromatography (SE-HPLC) demonstrated that ADA and salt induced protein aggregation. Moreover, ADA and salt induced a 2.37% and 7.47% decrease in weight loss, respectively, as detected by thermogravimetric analysis (TGA) when compared with MGFZ. The study provided insights into the effects of redox agents, salt, and acidic environments on zein-enriched wheat dough, potentially enhancing the applicability of zein in wheat-based products. • GSH, ADA, salt, and an acidic environment can impact the polymerization of zein and gluten. • Salt and ADA strengthened structures of zein-containing dough. • Acid condition given the zein added dough a uniform protein network structure. • Covalent& non-covalent interactions impact the properties of zein-wheat dough. [ABSTRACT FROM AUTHOR]

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]

Effects of kneading time (3–11 min) on properties of dough and quality and volatile compounds of Chinese steamed bread (CSB) were investigated. Rheological analysis showed that increasing kneading time induced less elastic and more viscous dough. CSB-7 min (dough kneaded for 7 min) exhibited the largest specific volume and cell porosity. Kneading induced the development of aroma-active compounds i.e. 2-pentylfuran and short-chain aldehydes. These aroma-active compounds were probably arisen from lipid oxidation with a combination of the hydroperoxides decomposition and the degradation of long-chain aldehydes (octanal, nonanal, decanal and (E)-2-nonenal). Sensory analysis indicted that CSB-9 min got the highest score for its aroma. Results indicated that the optimal kneading time to obtain CSB with highest texture quality was inconsistent to that with best aroma. Further efforts should be paid to deal with the problem. The current study was beneficial for understanding the critical role of dough kneading on CSB quality and volatile compounds. • Effects of kneading time on dough and CSB aroma and quality were investigated. • Long chain aldehydes rapidly decreased with the increasing kneading time. • Short chain aldehydes increased during dough kneading. • High lipoxygenase activity caused lipid oxidation. • Nonanal, (E)-2-nonenal and decanal were related with the raw-flour aroma. [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]

The utilization of frozen dough technology presents a compelling solution for prolonging the shelf life of flour products and enhancing production efficiency. This technology has been widely applied and continuously studied. However, the intricate production process of frozen dough introduces a persistent challenge—freezing damage—that impacts different components of frozen dough like starch, gluten protein, yeast, and lipid. This damage leads to a decline in dough quality. This review offers a comprehensive summary of changes occurring in different components in frozen dough from a multiscale perspective, specifically starch, gluten protein, lipid, and yeast. The process improvement methods involving from the main materials to the end products in the actual production process of frozen dough have been discussed. These encompass the selection and optimization of main materials, improvement of yeast freeze tolerance, additives, frozen processes (freezing, storage, and thawing), and dough-making processes. The selection of wheat flour with high gluten strength and the use of composite flour with high dietary fiber can improve the freezing resistance of gluten–starch matrix. The freeze tolerance of yeast can be improved through hybridization, genetic engineering, pretreatment with polycationic peptide (ε-poly- l -lysine), microencapsulation technology, and the addition of anti-freeze agents. In addition to improving the use-effect of different additives, effective methods of obtaining additives and synergistic combinations of multiple additives are in focus. Different frozen doughs need to choose an appropriate freezing rate. The novel physical field-assisted freezing technology has a positive effect on reducing freezing damage. For frozen storage, the subfreezing temperature (−12 °C) is more environmentally friendly and the lower storage temperature is more stable. The innovative microwave thawing has a poor application effect for frozen dough presently. Innovative dough-making processes such as vacuum mixing, heat treatment before dough freezing (part-baked, par-steamed, and preheated dough), and edible coatings are worth exploring. • The quality deterioration mechanism of frozen dough is elucidated with the changes of gluten–starch matrix and other components. • The improvement of the flour and yeast freezing tolerance can improve the quality of frozen dough. • Synergistic combinations of multiple additives can improve the effect of additives. • There is still plenty of room for innovation in frozen dough production such as freezing, storing, thawing and making dough. [ABSTRACT FROM AUTHOR]

Depolymerization of glutenin macropolymers (GMP) widely exists in the frozen dough with little effort in elucidating its effects on steamed bread quality. To clarify this, GMP was fractionated from wheat flour and reconstituted to yeast and chemical leavened dough (YLD/CLD). Results showed that with supplementary GMP fraction, depolymerization degree was alleviated in frozen dough. The bread quality loss from freezing was partially counteracted along with better preserved GMP content. Both of dough elasticity and gas retention capability were enhanced in GMP-enriched frozen dough. Gassing power in frozen YLD decreased while remained constant in CLD. Addition of GMP did not affect the gassing power, which allowed interpreting the improved bread qualities from the enhanced dough elasticity and gas retention capability. Based on the improved facts of frozen steamed bread dough quality with additional GMP fractions, this study revealed the pivotal role of GMP depolymerization on the frozen steamed bread dough quality. [ABSTRACT FROM AUTHOR]

Background Gluten proteins are considered as quality determinants in cereal-based food product by forming the backbone structure of dough. Freezing technique has largely expanded the dough shelf life and brought revolutionary development to the bakery industry. However, deterioration of gluten network in frozen dough is one of the major factors leading to the quality loss of bakery products. During the manufacturing process of frozen dough, hydration with optimum mixing is the first and critical step to manage the control dough quality, followed by the freezing and frozen storage to achieve the long time storage of dough, which determines the final dough quality. Scope and approach Series of physicochemical alterations in gluten proteins occur upon the dough formation and frozen storage. Understanding these fundamental changes is important for the research community to propose more rational implementation of specific improvement principals for frozen dough. In this review, the physicochemical alterations of wheat gluten proteins are investigated from the perspectives of gluten and its component glutenin and gliadin. Key findings and conclusions A more structure-ordered, homogeneous and elastic gluten network is formed at the optimum mixing stage as a consequence of glutenin and gliadin interactions. Comparative studies in different model systems demonstrate that further frozen storage exerts detrimental effects on gluten proteins in diverse ways from both gluten proteins-water interactions and structure-functionality perspectives. [ABSTRACT FROM AUTHOR]

The effects of starch and gluten on the physicochemical properties of frozen dough were studied using reconstituted flour. The profiles of frozen dough were studied by Mixolab, rheometer, scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Results revealed that starch, rather than gluten, played a decisive role in mixing properties. The breakdown and aggregation of the gluten network structure as well as the formation of β-turns and β-sheets in the frozen dough would be aggravated by the freezing of wheat starch. Smaller wheat starch granules (B-Type granules) affected the secondary structure of gluten network more than larger granules (A-Type granules), resulting in greater rheological property changes. The viscoelastic properties and freezable water content of frozen dough were more influenced by the freezing of gluten. [Display omitted] • Starch had more impact on mixing characteristics than gluten in frozen dough. • Frozen wheat starch would aggravate the disintegration and aggregation of gluten. • B-Type granules affected the secondary structure of gluten more than A-Type granules. • Gluten played a more important role in the viscoelastic properties of frozen 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 present study comparatively evaluated the evolution of yeast and chemical leavened steamed bread dough (YLD/CLD) quality during freeze/thaw (FT) cycles. The steamed bread quality of CLD was more freeze-stable than that of the YLD after 3 FT cycles. Decreased yeast viability contributed to the loss of gassing power in YLD while no significant differences were observed for CLD during FT cycles. However, faster gas release rate in frozen CLD indicated gas retention loss due to the distortion of gluten network. Glutenin macropolymers (GMP) depolymerization via breakage of inter-chain disulfide (SS) bonds and conversions of α-helix and β-turn to β-sheet structures were the main indicators of gluten deterioration. Gluten network was more vulnerable in frozen YLD, resulting in detectable loss of viscoelasticity. The results suggested that supplement of chemical leavener contributed to a more freeze-tolerant gluten network besides its stable gassing power. [ABSTRACT FROM AUTHOR]

Effect of pigskin gelatin and its hydrolysates on overall changes that frozen dough underwent during storage was investigated. The results showed that gelatin from pigskin could fortified the frozen dough bread quality, embodying in larger bread volume, softer and more uniform bread crumb. Impact of pigskin gelatin on changes in the structure of gluten network in frozen dough was evaluated by different techniques. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) showed gelatin may inhibit the crosslinking of HMW macromolecules and entangle with SDS-soluble LMW proteins. The increased SDS-soluble proteins suggested a lower aggregation extent of glutenin macropolymer (GMP) caused by pigskin gelatin. However, the significant reduction in GMP depolymerization degree and thiol groups (-SH) content after 60-day frozen storage in presence of gelatin indicated the formation of a more resistant gluten structure against the distortion of ice crystals. There were no significant differences in the alteration of secondary structure and high-temperature stability between gelatin-depleted and gelatin-fortified groups. Nevertheless, the effect of pigskin gelatin on qualities of frozen dough was independent on its hydrolysis degree. Image 1 • Gelatin from pigskin fortified the frozen dough bread quality. • Effect of pigskin gelatin on qualities of frozen dough was independent on its hydrolysis degree. • Pigskin gelatin resulted in a lower aggregation extent of glutenin macropolymer. • Gelatin inhibited the crosslinking of HMW macromolecules and entangle with SDS-soluble LMW proteins. [ABSTRACT FROM AUTHOR]

• B-Type granules were more sensitive to freezing than A-Type granules. • The properties of whole wheat starch were close to those of its A-Type granules. • A-Type granule gradually play a leading role in whole wheat starch with frozen time. • The deterioration of B-Type granule had little influence in whole wheat starch. The physicochemical properties of whole wheat starch and its A-Type and B-Type granules isolated from frozen dough at 0, 4 and 8 weeks of storage were investigated. Results showed that profiles of A-Type granules were more or less constant while significant differences of B-Type granules involving in irregular edges, increased relative crystallinities and decreased Viscosities were observed after 8 weeks of storage, suggesting that B-Type granules were more sensitive to freezing. These were mainly attributed to the release of leaching materials from starches, resulting in the ratio of amylose to amylopectin, protein and lipid content decreased by 25.93%, 12.05% and 31.65%, respectively. Whole wheat starch remained essentially unchanged during freezing. It seemed that B-Type granules, as a small part of whole wheat starch, had less influence on whole wheat starch than A-type granules in spite of their significant deterioration upon storage. [ABSTRACT FROM AUTHOR]