Thermomechanical behaviors and protein polymerization in bread dough modified by bran components and transglutaminase

Alleviative effects of Dendrobium officinale polysaccharide on the quality deterioration of frozen dough and corresponding bread

Dendrobium officinale polysaccharide (DOP), a natural hydrocolloid derived from polysaccharides, holds significant promise for enhancing the quality of frozen dough-based products. This research systematically examined the effects of DOP on the quality attributes of both frozen dough and the resulting bread throughout the period of frozen storage. Findings demonstrated that DOP enhanced thermal stability and slowed starch retrogradation. Dough containing 1.2 % DOP showed increased water absorption (68.63 ± 0.21 %), extended development time (8.63 ± 0.25 min), and decreased stability time (9.33 ± 0.06 min), along with diminished gluten strength and gelatinization viscosity. Moreover, higher concentrations of DOP markedly inhibited water migration, curtailed the rise in freezable water content, and reduced moisture loss during frozen storage (p < 0.05). The hydrophilic groups in DOP bound to free water, forming hydrogen bonds, which prevented the formation and growth of large ice crystals, thereby reducing deterioration of the microstructure and rheological properties of the frozen dough. Bread produced from DOP-enriched frozen dough exhibited improved baking performance, including enhanced textural properties, specific volume, slice structure, and color, particularly with higher concentrations of DOP. Consequently, DOP can serve as a natural enhancer to prevent the degradation of frozen dough quality.

The characterization of sensory properties, aroma profile and antioxidant capacity of noodles incorporated with asparagus tea ultra-micro powder

Asparagus tea enhances the taste and flavor of processed foods when used as an ingredient during preparation. In this study, asparagus tea ultra-micro powder was incorporated into wheat flour during the mixing process before noodle formation at levels of 5 %, 10 % and 20 %. Flavor analysis using electric nose (E-nose) and gas chromatography-mass spectrometry (GC-MS) revealed clear distinctions among 100 % wheat flour noodle, green asparagus tea ultra-micro powder noodles (GATUPNs) and white asparagus tea ultra-micro powder noodles (WATUPNs). Based on principal component analysis (PCA) of the volatiles using GC-MS, with a threshold of VIP > 1 and P < 0.05, the key flavor components of GATUPNs were 1-octen-3-ol, hexanal, (E)-2-octenal, pyrazine and 3,5-diethyl-2-methyl-(8Cl, 9Cl). In contrast, the key flavor components of WATUPNs were hexanal and (+)-dipentene. The antioxidant capacity of the noodles exhibited a dose-dependent relationship with the ATUP content, with GATUPNs showing the highest antioxidant activity.

Effect of transglutaminase on the structure, properties and oil absorption of wheat flour

The structure, properties, as well as the oil absorption characteristics of wheat flour (WF) treated with varying concentrations of transglutaminase (TG) (0 U/g ∼ 50 U/g) were characterized. The content of free amino groups in WF modified by TG (TG-WF) decreased and protein aggregated. The isopeptide bonds and disulfide bonds played important roles in protein crosslinking. The thermal stability, the peak viscosity after gelatinization and protein secondary structure stability of TG-WF were improved. In addition, the oil absorption and surface oil content of TG-WF after frying were reduced. TG enhanced the protein-protein interactions in WF, so that protein played barrier roles in the process of high-temperature frying, protecting the starch particles covered by them from the infiltration of oil, thus reducing the oil absorption of TG-WF during frying. Among them, the oil content of TG-WF-30 U/g after frying was the lowest, which decreased by 10.73 % compared with the control group.

Cereal dietary fiber regulates the quality of whole grain products: Interaction between composition, modification and processing adaptability

The coarse texture and difficulty in processing dietary fiber (DF) in cereal bran have become limiting factors for the development of the whole cereal grain (WCG) food industry. To promote the development of the WCG industry, this review comprehensively summarizes the various forms and structures of cereal DF, including key features such as molecular weight, chain structure, and substitution groups. Different modification methods for changing the chemical structure of DF and their effects on the modification methods on physicochemical properties and biological activities of DF are discussed systematically. Furthermore, the review focusses on exploring the interactions between DF and dough components and discusses the effects on the gluten network structure, starch gelatinization and retrogradation, fermentation, glass transition, gelation, and rheological and crystalline characteristics of dough. Additionally, opportunities and challenges regarding the further development of DF for the flour products are also reviewed. The objective of this review is to establish a comprehensive foundation for the precise modification of cereal DF, particularly focusing on its application in dough-related products, and to advance the development and production of WCG products.

Cereal-Derived Water-Unextractable Arabinoxylans: Structure Feature, Effects on Baking Products and Human Health

Arabinoxylans (AXs) are non-starch polysaccharides with complex structures naturally occurring in grains (i.e., barley, corn, and others), providing many health benefits, especially as prebiotics. AXs can be classified as water-extractable (WEAX) and water-unextractable (WUAX) based on their solubility, with properties influenced by grain sources and extraction methods. Numerous studies show that AXs exert an important health impact, including glucose and lipid metabolism regulation and immune system enhancement, which is induced by the interactions between AXs and the gut microbiota. Recent research underscores the dependence of AX physiological effects on structure, advocating for a deeper understanding of structure-activity relationships. While systematic studies on WEAX are prevalent, knowledge gaps persist regarding WUAX, despite its higher grain abundance. Thus, this review reports recent data on WUAX structural properties (chemical structure, branching, and MW) in cereals under different treatments. It discusses WUAX applications in baking and the benefits deriving from gut fermentation.

Feruloylation and Hydrolysis of Arabinoxylan Extracted from Wheat Bran: Effect on Dough Rheology and Microstructure

Feruloylated arabinoxylan (AX) is a potential health-promoting fiber ingredient that can enhance nutritional properties of bread but is also known to affect dough rheology. To determine the role of feruloylation and hydrolysis of wheat bran AX on dough quality and microstructure, hydrolyzed and unhydrolyzed AX fractions with low and high ferulic acid content were produced, and their chemical composition and properties were evaluated. These fractions were then incorporated into wheat dough, and farinograph measurements, large and small deformation measurements and dough microstructure were assessed. AX was found to greatly affect both fraction properties and dough quality, and this effect was modulated by hydrolysis of AX. These results demonstrated how especially unhydrolyzed fiber fractions produced stiff doughs with poor extensibility due to weak gluten network, while hydrolyzed fractions maintained a dough quality closer to control. This suggests that hydrolysis can further improve the baking properties of feruloylated wheat bran AX. However, no clear effects from AX feruloylation on dough properties or microstructure could be detected. Based on this study, feruloylation does not appear to affect dough rheology or microstructure, and feruloylated wheat bran arabinoxylan can be used as a bakery ingredient to potentially enhance the nutritional quality of bread.

Wheat gluten deamidation: structure, allergenicity and its application in hypoallergenic noodles

BACKGROUND

Wheat gluten (WG) containing gliadin and glutenin are considered the main allergens in wheat allergy as a result of their glutamine-rich peptides. Deamidation is a viable and efficient approach for protein modifications converting glutamine into glutamic acid, which may have the potential for allergenicity reduction of WG.

RESULTS

Deamidation by citric acid was performed to investigate the effects on structure, allergenicity and noodle textural properties of wheat gluten (WG). WG was heated at 100 °C in 1 m citric acid to yield deamidated WG with degrees of deamidation (DD) ranging from DWG-25 (25% DD) to DWG-70 (70% DD). Fourier-transform infrared and intrinsic fluorescence spectroscopy results suggested the unfolding of WG structure during deamidation, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed molecular weight shifts at the 35-63 kDa region, suggesting that the deamidation mainly occurred on low molecular weight glutenin subunits and γ- gliadin of the WG. An enzyme-linked immunosorbent assay of deamidated WG revealed a decrease in absorbance and immunoblotting indicated that the intensities of protein bands at 35-63 kDa decreased, which suggested that deamidation of WG might have caused a greater loss of epitopes than the generation of new epitopes caused by unfolding of WG, and thereby reduction of the immunodominant immunoglobulin E binding capacity, ultimately leading to the decrease in allergenicity. DWG-25 was used in the preparation of recombinant hypoallergenic noodles, and the hardness, elasticity, chewiness and gumminess were improved significantly by the addition of azodicarbonamide.

CONCLUSION

The present shows the potential for deamidation of the WG products used in novel hypoallergenic food development. © 2023 Society of Chemical Industry.

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.

Effect of soy protein hydrolysates incorporation on dough rheology, protein characteristic, noodle quality, and their correlations

Soy protein hydrolysates (SPHs) have bioactive and nutritional functions that can be used as fortifier of noodles. The objective of this study is to explore the effect of SPHs on dough rheology and noodle quality. Two kinds of SPHs, with a hydrolysis degree of 4.43% (SPH4) and 7.47% (SPH7), were added to wheat flour at a ratio of 5:95 to make dough and noodles. The addition of SPHs decreased the gluten yield, gluten index, peak viscosity, final viscosity, and setback of flour paste. Dough stability decreased, but the extensibility increased because of the addition of SPHs. SPHs decreased the high molecular weight glutenin subunits and SDS-unextractable polymeric protein proportion, and the results of scanning electron microscopy and atomic force microscopy also showed that the gluten network in SPH7 dough was more discontinuous than that in SPH4, suggesting a stronger negative effect of SPH7 on the formation of the gluten network compared to that of SPH4. The incorporation of SPHs decreased the hardness and springiness of cooked noodles but increased their cooking loss, protein loss, and water absorption. The correlation analysis showed that high molecular weight subunits and SDS-unextractable polymeric protein in SPH-fortified dough were positively correlated with the hardness, adhesiveness, springiness, cohesiveness, chewiness, resilience, force, and distance at break of noodles, and these texture properties of noodles were positively correlated with pasting, gluten, and farinographical properties of SPH-fortified flour. These results suggested that SPHs could improve some qualities of noodles, such as smoothness and cooking yield, and resist pasted starch aging. PRACTICAL APPLICATION: Soy protein hydrolysates have many bioactive functions. This study demonstrated the feasibility of incorporating soy protein hydrolysates into wheat flour to prepare noodles. The addition of soy protein hydrolysates gives noodles smoother mouthfeel and increases the cooking yield. The addition of soy protein hydrolysates decreases the setback value of flour paste, suggesting that soy protein hydrolysates may help to resist starch aging, which is favorable for starch-containing foods such as precooked noodles. Thus, soy protein hydrolysates possess potential applications in noodle products.