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Summary: The effects of reduced glutathione (GSH) on dough rheology, water state and distribution, gluten conformation, and protein molecular weight distribution were investigated. Addition of GSH (0.02−0.04%) resulted in a more viscous and less elastic dough with decreased G′ and increased tanδ values, which suggested decreased cross‐links in gluten network and a weakened dough structure. The molecular weight of proteins was reduced by the GSH‐induced cleavage of intermolecular disulphide bonds. Fourier transform infrared spectroscopy showed a high fraction of β‐sheet formation at the expense of α‐helix and β‐turns, indicating a destabilised secondary structure and protein depolymerisation. GSH increased water release from the gluten network in dough resulting in an increase in freezable water content and caused water redistributed from bound water to weakly bound water. This study provided insights into correlation between wheat dough rheological properties and gluten structure influenced by GSH. [ABSTRACT FROM AUTHOR]

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]

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]

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]

This study was to investigate the protective effect of magnetic field (MF) on frozen dough processing quality. The texture, microstructure, rheological and physicochemical properties of wheat dough treated by freezing-thawing cycles under different magnetic flux densities (0, 2, 4, 6, 8, and 10 mT) were analyzed. Compared with conventional frozen dough, MF-treated frozen dough had lower hardness and higher elasticity. Scanning electron microscope exhibited that MF treatment minimized the freezing-induced damages on morphology of starch and gluten, which was consistent with the decreased tan δ in rheological analysis. Application of MF facilitated high relative crystallinity and gelatinization enthalpy in starch granules while the depolymerization of gluten macropolymer was inhibited as manifest with more ordered secondary structure and decreased free sulfhydryl groups. The integrated structure in MF-treated frozen dough resulted in lower free water content as shown by low field nuclear magnetic resonance. The results provided valuable knowledge for the MF-assisted freezing technology and made it possible to improve the freezing-induced deteriorations on wheat-based food. • Wheat dough was frozen/thawed with different magnetic field(MF) intensities. • Freezing-induced damages on starch granule and gluten were repaired by MF. • MF resulted in high starch crystallinity and lower gluten depolymerization. • MF caused a softer hardness and higher elasticity compared with frozen dough. [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]

Flavourzyme is a commercial peptidase, mainly with exopeptidase activity. In this study, effects of Flavourzyme addition (0–0.16 g/100 g) on properties of wheat dough and bread were systematically studied. Bread with a low concentration (0.01–0.08 g/100 g) of Flavourzyme addition had a large specific volume and soft texture with a uniform cell structure. The optimal Flavourzyme content was 0.04 g/100 g and the specific volume increased from 3.9 mL/g to 4.4 mL/g, the hardness decreased from 21.7 N to 13.3 N. The gas production capacity of yeast increased with low concentrations of Flavourzyme addition, promoting dough expansion. Flavourzyme had a clear hydrolysis effect on wheat gluten in dough and caused the depolymerization and unfolding of gluten structure, thus decreasing the strength and viscoelasticity of dough. Confocal laser scanning microscopy and scanning electron microscopy results further revealed that a low concentration of Flavourzyme had a slight effect on gluten. However, the gluten structure became discontinuous and open, which made the dough easily collapsed during fermentation, resulting in poor bread quality with high Flavourzyme content. The positive effects of appropriate amount of Flavourzyme addition on dough and bread properties indicated the potential of Flavourzyme as a bread improver by substituting chemical additives. • Moderate amount of Flavourzyme addition improved the quality of bread significantly. • The optimal addition of Flavourzyme is 0.04 g/100 g (based on wheat flour). • Dough expansion was enhanced with moderate Flavourzyme addition. • Moderate Flavourzyme addition did not cause obvious damage to gluten network. [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]

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]