Impact of xanthan gum on gluten microstructure and bread quality during the freeze-thaw storage

Effects of dextran molecular weight on starch retrogradation and technological properties of Chinese steamed bread: Based on the rubber/glass transition

From the perspective of rubber/glass transition, this study clarified that the impact of dextran on retarding hardening behavior and slowing starch retrogradation of Chinese Steamed Bread (CSB) depended on its molecular weight and concentration level. Guggenheim-Anderson-de Boer (GAB) model was fitted to explore critical behavior changes in rubber/glass transition of CSB. Incorporation of high molecular weight dextran enhanced the elasticity of dough and porosity of CSB, reduced the aging and hardening degree of CSB at appropriate addition levels. CSB hardness showed a growing tendency during storage, while macromolecular dextran reduced the hardness and retrogradation degree by 22.87 % and 67.53 %. Dextran with high molecular weights lowered the glass transition temperature (Tg) and improved the moisture sorption and molecular mobility of CSB under various relative humidity (RHs) conditions by providing hydrophilic sites or intermolecular space to bind water molecules. Meanwhile, it reinforced the binding between denatured gluten and gelatinized starch. Both of them devoted to starch retrogradation inhibition and stable quality maintenance of CSB. CSB is suggested to maintain stable quality at room temperature with RHs ≤33 % to prevent rubber/glass transition. This work provided theoretical guidance for fractionation application of dextran to regulate the quality and extend the shelf-life of flour products.

Monitoring the Dough Properties, Quality Characteristics and Volatile Compounds of Whole Wheat Bread Made by Different Sourdough Types during Frozen Storage

There is a need to increase the consumption of whole wheat bread (WWB) due to its health benefits by overcoming its poor technological quality and improving its sensory characteristics. In this study, sourdough bread-making and frozen dough technology were combined to provide fresh WWB at any time with better quality. Also, it was aimed to investigate the effects of three types of sourdough (type I, II, and IV) on the final quality of WWB during frozen storage (-30 °C, 14 and 28 days). The tan δ of WWB with type I sourdough was highest at the end of the frozen storage. Freezable water content was lower on day 0 for WWB with type II and IV sourdough than other bread types. No significant effect of frozen storage was observed in bread types in terms of an α helix structure, except for WWB with type I sourdough. A lower hardness increment was shown in WWB with baker's yeast and WWB with type II sourdough over 14 days of frozen storage when compared to other bread types. WWB with type I sourdough and WWB with type IV sourdough were differentiated from other bread samples in volatile compound (VC) analysis on frozen storage days 28 and 0, respectively. The frozen storage of WWB with baker's yeast and WWB with type II sourdough caused no notable changes in the VCs profile. These results suggest that a less detrimental effect of frozen storage was observed in WWB with type II sourdough, indicating a more favorable choice for producing WWB with sourdough.

Quality attributes and functional properties of whole wheat bread baked from frozen dough with the addition of enzymes and hydrocolloids

BACKGROUND

The increased demand for healthy and standardized bread has led to a demand for an efficient and promising dough improver, of natural origin, to reduce the deterioration of whole wheat bread baked from frozen dough caused by the high levels of dietary fiber and by freezing treatment. In this study, the combined effects of xylanase (XYL), lipase (LIP), and xanthan gum (XAN) on the quality attributes and functional properties of whole wheat bread baked from frozen dough were evaluated.

RESULTS

The optimal combination, which contained XYL (0.12 g kg-1 ), LIP (0.25 g kg-1 ), and XAN (3.1 g kg-1 ), was obtained using response surface methodology (RSM). The addition of the optimal combination endowed frozen dough bread with a higher specific volume, softer texture, better brown crumb color, and greater overall acceptability. The optimal combination had no adverse impact on the volatile organic compounds (VOCs) of frozen dough bread. In terms of the functional properties of bread, the water-holding capacity (WHC), oil-holding capacity (OHC), and swelling capacity (SWC) of dietary fiber in frozen dough bread decreased in the presence of the optimal combination, whereas the glucose adsorption capacity (GAC) did not affect them. Correspondingly, the in vitro digestive glucose release was not significantly different between the control group and the optimal combination group after frozen storage.

CONCLUSION

The optimal combination could improve the quality attributes and functional properties of whole wheat bread baked from frozen dough effectively, thereby increasing consumption. © 2023 Society of Chemical Industry.

Adequately increasing the wheat B-starch ratio can improve the structure-properties of dough during freeze-thaw cycles: Mechanisms and conformational relations

To reveal the influence of wheat starch particle size distribution on frozen dough quality, this study reconstituted A/B starch according to 100:0, 75:25, 50:50, 25:75 and 0:100 and prepared reconstituted dough by compounding with gluten proteins. Further, the freeze-thaw cycle of 1, 3, and 9 times for reconstituted dough was performed to investigate its ratio-regulatory role of A- and B-starch. The results showed that the freeze-thaw cycle induced gluten network breakage and starch granule exposure in doughs mainly by disrupting disulfide and hydrogen bonds between gluten protein molecules and upsetting their secondary structures, leading to a reduction in GMP and polymer protein content and an increase in freezing water content. Moreover, a moderate increase (25-50 %) in the B-starch proportion can minimize gluten protein deterioration by freeze-thaw cycles. However, excessive B-starch amounts (75-100 %) can also adversely affect gluten structure. The prepared dumpling wrappers under the 50A-50B ratio showed optimal steaming loss rate, hardness, and chewiness during the freeze-thaw cycle. Correlation analysis indicated that the B-starch ratio and its filling pattern improved dough freeze-thaw deterioration primarily by affecting dough-free sulfhydryl content, protein molecular weight distribution, secondary structure, and ΔH. The results may provide insights and guidelines for product development and storage for frozen pasta.

Effects of Xanthan gum and Potassium carbonate on the quality and flavor properties of frozen Jiuniang doughs

Chinese Jiuniang (CJ) is a flavorful and nutritious food, but underutilized in frozen dough (FD) production. In addition, frozen storage can harm FD's gluten structure and degrade quality and flavor. Therefore, the impacts of two excellent protective agents (XG-Xanthan Gum; PC-Potassium Carbonate) on frozen Jiuniang dough (F-JD) quality and flavor during dynamic freezing were investigated. The results suggested that adding XG conferred F-JD with good processing stability, maintained the bound water levels, stabilized rheological properties, diminished ice crystal damage to the protein structure, and inhibited the increase in frozen water content during the freezing process. In contrast, although PC reduced free water production during freezing, it increased dough hardness and offered less protein protection than XG. Additionally, GC-QTOF/MS analysis showed that adding XG during freezing increased the relative content of pleasant flavor compounds like Phenylethyl Alcohol and decreased undesirable ones like Hexanal. Moreover, PC lowered the relative content of undesirable flavor substances (Formic acid) but reduced the relative content of beneficial flavor compounds (1-Hexanol). Importantly, the study confirmed that XG maintained the new F-JD product's storage quality during dynamic freezing. In conclusion, this study broadens CJ's application possibilities and provides new insights into mechanisms for preserving F-JD's quality and flavor.

Insight into curdlan alleviating quality deterioration of frozen dough during storage: Fermentation properties, water state and gluten structure

Curdlan was effective in alleviating quality deterioration of frozen dough during storage. This research explored the mechanisms from perspectives of fermentation properties, water state and gluten structure of frozen dough during storage, and the performance of corresponding steamed bread. Results showed that curdlan addition improved the gas-releasing capability and gas-holding capability of frozen dough, meanwhile enhanced the specific volume and textural properties of corresponding steamed bread. The melting enthalpy and NMR results demonstrated that curdlan restricted the conversation of bound water into freezable water, and inhibited the moisture migration in frozen dough. Frozen dough with 0.5% curdlan had significantly lower gluten macropolymers (GMP) depolymerization degree and free sulfhydryl (SH) content than the control, indicating that curdlan alleviated the depolymerization of GMP. Microstructure results proved that the deterioration of the structure was retarded by curdlan. This study contributes to understanding the theories for curdlan alleviating the deterioration of frozen dough during storage.

The innovative technology of dough preparation for bread by the accelerated ion-ozone cavitation method

Due to the fact that bakery, pasta and flour confectionery products are produced mainly from premium or first-grade flour, which is poor in the content of nutrients and fiber, the issue of developing technology for new types of flour products based on whole-ground flour of different fineness is very relevant and in demand. In the production of wholemeal flour, all parts of the whole grain are used-germ, grain shells, and endosperm. Also, recently the shortage of quality wheat has been growing. Therefore, the use of whole-milled flour from low-class wheat varieties will solve the problem of meeting the needs of the population. Using ion-ozone technology for preparing bread, high-quality bakery products from third-class flour with high nutritional and biological value were obtained. Using the obtained system of equations and constraints, the optimal modes of ion-ozone cavitation processing of dough were determined by a nonlinear programming method, which, subject to all the constraints (limitations) on the dough quality, provided the maximum dough strength of y2 = 181.0% and the dough parameter values of C × 10-4 = 25 units/mg, P = 1 atm, and τ = 5 min, which, in compliance with all constraints (restrictions) on the bread quality, provided a maximum volume of z11 = 232.1 cm3. A new innovative technology was created to increase productivity, efficiency and shorten the preparation time of bread. The method of making bread with the effect of ion-ozone cavitation of dough is very important for the bread industry, which affects the effectiveness of whole wheat flour obtained from the lower class of wheat, increases the quality of bread, shortens the technological processes of production, and increases labor productivity indicators. This method increases the economic efficiency of bread-making industries and the productivity of bread.

The Effect of Freeze-Thaw Cycles on the Microscopic Properties of Dumpling Wrappers

Dumplings are a traditional Chinese food welcomed by Chinese people. Research has indicated that process of quick-frozen wheat cultivars and their gliadins are all related to the quality and shelf-life of dumplings. Therefore, the effect of freeze-thaw cycles on the textural properties and microscopic characteristics of two types of quick-frozen dumpling wrappers (Zhaomai and Wenmai 19) and conformation of their gliadins were investigated. Scanning electron microscopy showed that Wenmai 19 dumpling wrappers had apparent damage after the first cycle, but Zhaomai wrappers did not reveal significant changes until the fourth cycle. The particle size distribution in the starch granules of Wenmai 19 wrappers varied in terms of mechanical damage, but Zhaomai delayed or avoided such effects. FT-IR found a loose protein structure of the gliadins. Differential scanning calorimetry showed that gliadins of Wenmai 19 degenerated more than those of Zhaomai. The crosslinking of gliadin and glutenin maintained a high-quality gluten network, thus protecting the gliadin stability from ice crystals. In turn, the gliadin maintained the strength of the gluten network. Therefore, raw flours with high-quality protein networks are more suitable for frozen dumplings. Freeze-thaw cycles dramatically decreased the textural characteristics of dumpling wrappers and the microscopic characteristics of their gliadin proteins. Concerning wheat cultivars with weak gluten, flours with high-quality protein networks are more suitable as raw materials for frozen dumplings.

Classification, gelation mechanism and applications of polysaccharide-based hydrocolloids in pasta products: A review

Polysaccharide-based hydrocolloids (PBHs) are a group of water-soluble polysaccharides with high molecular weight hydrophilic long-chain molecules, which are widely employed in food industry as thickeners, emulsifiers, gelling agents, and stabilizers. Pasta products are considered to be an important source of nutrition for humans, and PBHs show great potential in improving their quality and nutritional value. The hydration of PBHs to form viscous solutions or sols under specific processing conditions is a prerequisite for improving the stability of food systems. In this review, PBHs are classified in a novel way according to food processing conditions, and their gelation mechanisms are summarized. The application of PBHs in pasta products prepared under different processing methods (baking, steaming/cooking, frying, freezing) are reviewed, and the potential mechanism of PBHs in regulating pasta products quality is revealed from the interaction between PBHs and the main components of pasta products (protein, starch, and water). Finally, the safety of PBHs is critically explored, along with future perspectives. This review provides a scientific foundation for the development and specific application of PBHs in pasta products, and provides theoretical support for improving pasta product quality.

Structural, rheological and functional properties of ultrasonic treated xanthan gums

Xanthan gum can improve the freeze-thaw stability of frozen foods. However, the high viscosity and long hydration time of xanthan gum limits its application. In this study, ultrasound was employed to reduce the viscosity of xanthan gum, and the effect of ultrasound on its physicochemical, structural, and rheological properties was investigated using High-performance size-exclusion chromatography (HPSEC), ion chromatograph, methylation analysis, 1H NMR, rheometer, etc.. The application of ultrasonic-treated xanthan gum was evaluated in frozen dough bread. Results showed that the molecular weight of xanthan gum was reduced significantly by ultrasonication (from 3.0 × 107 Da to 1.4 × 106 Da), and the monosaccharide compositions and linkage patterns of sugar residues were altered. Results revealed that ultrasonication treatment mainly broke the molecular backbone at a lower intensity, then mainly broke the side chains with increasing intensity, which significantly reduced the apparent viscosity and viscoelastic properties of xanthan gum. The results of specific volume and hardness showed that the bread containing low molecular weight xanthan gum was of better quality. Overall, this work offers a theoretical foundation for broadening the application of xanthan gum and improving its performance in frozen dough.

Effect of hydrocolloids on gluten proteins, dough, and flour products: A review

Hydrocolloids are among the most common components in the food industry, which are used for thickening, gel formation, emulsification, and stabilization. Previous studies have also found that hydrocolloids can affect the structures and properties of gluten proteins, dough, and flour products. In this review, hydrocolloids were separated into three categories: anionic, nonionic, and other hydrocolloids, and reviewed the effects of common hydrocolloids on gluten proteins, dough, and flour products. Hydrocolloids can affect the structures and properties of gluten proteins through gluten-hydrocolloids interaction, secondary structures, disulfide bonds, environment of aromatic amino acids, and chemical bonds. The properties of dough are affected by rheological, fermentation, and thermomechanical properties. Hydrocolloids are widely used in bread, Chinese steamed bread, noodles, yellow layer cake, and so on, which mainly affect their appearance, texture, and aging speed. This comprehensive review provides a scientific guide for the development and utilization of hydrocolloids and their applications in flour products, and provides a theoretical basis for improving the processing characteristics of products.

Research of the influence of xanthan gum on rheological properties of dough and quality of bread made from sprouted wheat grain

The effect of microbial polysaccharide xanthan in the amount of 0.1-0.4% on the rheological characteristics of the dough from sprouted wheat grain and quality indicators of bread was studied. It was found that when xanthan gum is added, the dough's spreading and adhesion strength decreases, and the dough's resilience-elastic and plastic-viscous characteristics improve. Bread made from sprouted wheat grains with the addition of experimental dosages of xanthan has better structural-mechanical and physicochemical properties, as evidenced by higher indicators of crumb compressibility, specific volume, and moisture compared to the control sample. To obtain bread with the best quality indicators, it is recommended to use 0.3% xanthan.