Low-sodium salt mediated aggregation behavior of gluten in wheat dough

Mechanism underlying the effect of soluble oat β-glucan and tea polyphenols on wheat gluten aggregation characteristics

The mechanism of how the coexistence of oat β-glucan (OβG) and tea polyphenols (TP) impacts gluten aggregation properties was investigated. The OβG might form interchain hydrogen bondings and compete for water with gluten, which could increase gluten aggregation and the gluten network's expansion, leading to its increasing average particle size (by 17.23 %) with 5%OβG. The physicochemical characteristics of TP and OβG + TP groups showed similar changing trends, indicating the predominant effect of TP; however, the effect was, to some extent, enhanced with the presence of OβG. This might be because OβG induced a more expanded network of gluten, favoring the access and attack of TP to unfold or disrupt the gluten structure by breaking disulfide bonds, as confirmed by the red-shifts in fluorogram, increasing content of free sulfhydryl by 250 % (without OβG) and 312 % (with OβG), and decreasing particle size of gluten by 10.43 % (without OβG) and 21.08 % (with OβG) when the addition of TP was 2 %. Moreover, with the increasing of TP, the tremendous unfolding or disrupting gluten structure exposed more amino acids whereas decreased the intermolecular contacts and extended chains of gluten, consequently leading to the increasing hydrogen bonds and hydrophobic interactions while reducing the content of β-sheets, respectively.

Effects of interaction between wheat bran dietary fiber and gluten protein on gluten protein aggregation behavior

Effects of wheat bran dietary fiber (WBDF) as a nutritional additive on flour products quality mainly depends on the interaction between WBDF and gluten protein. In this study, the effects and mechanisms of WBDF with different particle sizes and additive amounts on gluten protein aggregation behavior were investigated. The results showed that the addition of WBDF led to a decrease in free sulfhydryl content, particle size, molecular weight and gluten macromer (GMP) content, an increase in zeta potential and SDS-extractable protein content, and a deterioration in the gluten network morphology compared to the control group, suggesting that the aggregation behavior of gluten protein was inhibited. When WBDF was added at 3 % and 6 %, dilution effect, mechanical shear, steric hindrance, and non-covalent binding were the main mechanisms leading to depolymerization. Further addition of WBDF (9 %, 12 %) inhibited the depolymerization of gluten protein due to competitive hydration and non-covalent binding. However, when WBDF was added at 15 %, the dilution effect, mechanical shear and steric hindrance of WBDF (88 μm < particle size<150 μm) dominated, and their inhibitory of aggregation induced the formation of a loose gluten network structure. In contrast, the weaker mechanical shear and steric hindrance effects of WBDF (particle size<88 μm) mitigated the degradation of gluten network structures by WBDF.

Effects of apple fiber on the physicochemical properties and baking quality of frozen dough during frozen storage

The effects of apple fiber on gluten structure and corresponding frozen dough quality during frozen storage were studied. The addition of 0.50% and 0.75% apple fiber effectively preserved gluten structure by inhibiting the breakage of disulfide bonds and promoting the formation of hydrogen bonds. Notably, the presence of 0.75% apple fiber increased the β-turn of gluten from 29.60% to 33.84%. Fiber-enriched frozen dough exhibited a smoother and more compact microstructure, but excessive fiber addition (more than 1.00%) had adverse effects. The freezable water content of frozen dough decreased as fiber addition increased. Correspondingly, the addition of 1.50% apple fiber resulted in a 56.08% increase in storage modulus, indicating improved viscoelasticity of the dough. Consequently, the addition of 0.50% and 0.75% apple fiber alleviated the quality deterioration of frozen dough bread in terms of larger specific volume, softer and more uniform crumb.

Potassium Chloride as an Effective Alternative to Sodium Chloride in Delaying the Thermal Aggregation of Liquid Whole Egg

The potential of potassium chloride (KCl) to be used as a substitute for sodium chloride (NaCl) was studied by monitoring the effects of salt treatment on thermal behavior, aggregation kinetics, rheological properties, and protein conformational changes. The results show that the addition of KCl can improve solubility, reduce turbidity and particle size, and positively influence rheological parameters such as apparent viscosity, consistency coefficient (K value), and fluidity index (n). These changes indicate delayed thermal denaturation. In addition, KCl decreased the content of β-sheet and random coil structures and increased the content of α-helix and β-turn structures. The optimal results were obtained with 2% KCl addition, leading to an increase in Tp up to 85.09 °C. The correlation results showed that Tp was positively correlated with solubility, α-helix and β-turn but negatively correlated with ΔH, turbidity, β-sheet and random coil. Overall, compared to NaCl, 2% KCl is more effective in delaying the thermal aggregation of LWE, and these findings lay a solid theoretical foundation for the study of sodium substitutes in heat-resistant liquid egg products.

Influence of magnetic field on gluten aggregation behavior and quality characteristics of dough enriched with potato pulp

This study investigated the effect of varying magnetic field intensities (ranging from 0 to 10 mT) on the quality characteristics of dough with 40 % potato pulp substitution (DPP). The results indicated that the DPP fermented with a 4 mT magnetic field exhibited a significant enhancement in the combination of water and substrate, thereby elevating the viscoelastic properties of DPP through reinforcing the stability of gluten network. Meanwhile, DPP treated with a 4 mT magnetic field exhibited the highest amount of disulfide bonds (11.64 μmol SS/g sample). This is accompanied by a prominent cross-linkage structure, as evidenced by SDS-PAGE and CLSM. Notably, the application of a magnetic field substantially augments the dough's capacity to retain gas during fermentation. In addition, the application of magnetic field significantly increased the wet gluten content (20.85 %, P < 0.05) in DPP, which improved tensile properties and an acceptable color profile. The introduction of a magnetic field induces gluten aggregation, which in turn results in heightened particle size distribution and ζ-potential values. In conclusion, this study emphasize the potential of magnetic field technology as a viable method to enhance the overall quality attributes of dough enriched with potato pulp substitution.

Effect of Thermal Treatment on the Self-Assembly of Wheat Gluten Polypeptide

Self-assembled fibrillation of wheat gluten is a common phenomenon in the daily production and processing of wheat flour products. The driving forces for its formation and the factors that influence the morphology of fibrils have not been thoroughly investigated. In this study, the effect of three bonding changes (breaking hydrogen bonds, strengthening hydrophobic interactions, and SH-SS exchange reactions) on gluten polypeptide (GP) fibrillation was simulated by adjusting the heating temperature (room temperature (RT), 45 °C, 65 °C, and 95 °C). The results showed that the breakage of hydrogen bonds could induce conformational transitions in GPs and help to excite fibrillation in GPs. Strengthened hydrophobic interactions significantly contributed to the fibrillation of GPs. Covalent crosslinks generated by SH-SS exchange reactions might also promote the fibrillation of GPs. GPs with different degrees of hydrolysis (4.0%, 6.0%, and 10.0%, represented by DH 4, DH 6, and DH 10, respectively) presented different extents of fibrillation, with DH 10 GPs having a higher propensity to fibrillation than DH 4 and DH 6 GPs. The results of Fourier's transform infrared spectroscopy indicated that hydrophobic interactions drive the transition from a random coil and α-helix to a β-sheet. In addition, hydrophobic interactions also drive the intermolecular polymerization of GPs, resulting in larger molecular weight aggregates. The morphology presented by transmission electron microscopy showed that the greater the DH, the stronger the tendency for the worm-like aggregation of GPs.