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The volatile profiles of wheat flour during maturation were examined through headspace solid-phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) combined with electronic nose (E-nose) and electronic tongue (E-tongue) analyses. The wheat flour underwent maturation under three distinct conditions for predetermined durations. While GC/MS coupled with E-tongue exhibited discernment capability among wheat flour samples subjected to varying maturation conditions, E-nose analysis solely relying on principal component analysis failed to achieve discrimination. 83 volatile compounds were identified in wheat flour, with the highest abundance observed in samples matured for 50 d at 25 °C. Notably, trans-2-Nonenal, decanal, and nonanal were the main contributors to the characteristic flavor profile of wheat flour. Integration of HS-SPME-GC/MS with E-tongue indicated superior flavor development and practical viability in wheat flour matured for 50 d at 25 °C. This study furnishes a theoretical groundwork for enhancing the flavor profiles of wheat flour and its derivative products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The effect and mechanism of sanxan on the quality of salt-free noodles (SFNs) were investigated from different cooking stages (initial stage, 1 min; optimum cooking time, OCT; overcooked time, OT). The results showed significant changes in the cooking process with the addition of 1.2% sanxan. The OCT for noodles with 1.2% sanxan (experimental group, EG) was extended from 5 to 7 min compared to the non-added noodles (blank group, BG) and 1.5% salt-containing noodles (control group, CG). The hardness and adhesiveness of BG, EG, and CG all decreased significantly during cooking. In contrast, the springiness, maximum tensile strength, and tensile fracture distance trended first to increase and then to decrease. At OCT, EG had the highest hardness (3971.69 ± 94.49 g), adhesiveness (372.26 ± 33.56 g s), and maximum tensile strength (41.51 ± 2.76 g), which remained large even after overcooking. However, those in BG and CG showed a significant reduction (p < 0.05). The proportion of free water increased progressively as cooking progressed, with CG showing the largest increase, from 82.29% to 91.19%, whereas EG showed the smallest increase, from 78.34% to 86.02%. During the cooking process, the addition of sanxan delayed the water migration, whereas salt promoted it. Sensory evaluation showed that EG was smoother in appearance than BG and tasted malty with a slight stickiness. Moreover, EG had the smallest k 1 and C ∞ values. Thus, sanxan is an effective additive to enhance the quality of SFNs and can replace the role of salt in noodles in some properties, which is beneficial for the development of SFNs., (© 2023 Institute of Food Technologists.)

Influence of low-sodium salt on water mobility, chemical interactions, and structural changes in noodles was investigated to explore the underlying mechanisms of noodle quality changes, and the results were in comparison with those of NaCl and KCl. Low-sodium salt increased the cooking loss, hardness, chewiness, maximum tensile strength, and tensile fracture distance of noodles. Low-sodium salt enhanced the interaction of water and non-aqueous components in noodles by reducing water mobility. Besides, chemical interaction test showed that low-sodium salt induced the oxidation of some free SH groups to form SS bonds, and strengthened the hydrophobic interaction and hydrogen bonds of gluten. Fluorescence spectra revealed that low-sodium salt changed the microenvironment of gluten molecules. Scanning electron microscopy (SEM) images showed that low-sodium salt noodles presented a more continuous and compact microstructure. Among the three kinds of salted noodles, some qualities of low-sodium salt noodles were equivalent to or slightly worse than those of NaCl noodles, but higher than those of KCl noodles. Hence, replacing part of NaCl with KCl in noodle products is an effective method to reduce sodium content., (© 2022 Wiley Periodicals LLC.)

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.

The maturation of wheat flour is a transformative process that elevates its processing and culinary attributes to their peak performance levels. Despite extensive research on starch and gluten protein modifications, the impact of lipid changes has been largely unexplored. This study addresses this gap by examining the maturation of freshly milled wheat flour at 15 °C, 25 °C, and 40 °C over 60 days, focusing on enzymatic activities—lipase, lipoxidase, and catalase—and lipid metabolites, including free fatty acids, conjugated trienes, p-anisidine value, and total oxidation value. The results of this study showed that free fatty acids continued to increase at all temperatures, with the most significant increase of 50% at 15 °C. The p-anisidine value followed a pattern of initial increase followed by a decline, while conjugated trienes were markedly higher at 40 °C, suggesting temperature's significant influence on lipid peroxidation. Notably, total oxidation values became erratic post 30 days, indicating a shift in oxidative dynamics. This study underscores the correlation between lipid metabolites and enzymatic activities, revealing the enzymes' pivotal role in lipid oxidation. The interplay of temperature and time offers valuable insights for optimizing wheat flour maturation, ensuring superior quality for various applications. [ABSTRACT FROM AUTHOR]

Solvent retention capacity (SRC) is a test for the solvation of wheat flour. Its functional contribution was predicted according to the swelling behavior of different diagnostic solvents to different polymeric components of wheat. Ten commercial wheat flour varieties were used as raw materials in this study. The flour quality, gluten aggregation and solvent retention capacity, and their correlations were analyzed. The results showed that protein content, wet gluten content, dry gluten content and the swelling index of glutenin were positively correlated with torque maximum (BEM), torque 15 s before maximum torque (AM), torque 15 s after maximum torque (PM) and gluten aggregation energy (AGGEN). Moreover, they were significantly correlated with the solvent retention capacity. BEM, AM, PM and AGGEN were positively correlated with standard solvent water-SRC (WSRC) and lactic acid-SRC (LASRC). For supplemental solvents, ethanol-SRC (EthSRC) was positively correlated with AGGEN. Sodium dodecyl sulphate-SRC (SDSSRC) was highly correlated with peak maximum time (PMT). Metabisulfite-SRC (MBSSRC) and MBS + SDSSRC were also significantly correlated with BEM, AM, PM and AGGEN sodium metabisulfite. There were significant correlations between gluten aggregation characteristic, standard SRC solvent and supplemental solvent. This study provides a theoretical basis for the evaluation of wheat flour quality. [ABSTRACT FROM AUTHOR]

Reducing sodium in foods has attracted the attention of consumers, it is therefore necessary to explore sodium alternatives (i.e., low-sodium salt). However, the mechanism of low-sodium salt on gluten in dough remains unclear. Effect of low-sodium salt on the aggregation behaviors of gluten in dough was investigated and compared with those with NaCl and KCl in this study. The results showed that low-sodium salt enhanced gluten strength and prolonged gluten aggregation time. Low-sodium salt decreased the content of SDS extractable protein under non-reducing conditions. Low-sodium salt changed the spatial conformation of gluten by reducing β-turn structure and increasing β-sheet structure. Confocal laser scanning microscopy images indicated that low-sodium salt promoted the formation of a larger and dense gluten network. In summary, this study showed that low-sodium salt promoted the aggregation of gluten in dough, and the change of gluten structure explained this aggregation mechanism. Its mode of action was similar to NaCl and KCl, which provided a theoretical basis for the study of sodium substitutes in flour products. • Low-sodium salt enhanced gluten strength and prolonged gluten aggregation time. • Low-sodium salt reduced SDS extractable protein content in dough. • Low-sodium salt increased D 32 and D 43 of gluten in dough. • Low-sodium salt changed spatial structure of gluten in dough. • Low-sodium salt promoted the formation of a larger and dense gluten network. [ABSTRACT FROM AUTHOR]

Sweet potato flour (SPF), as a functional substitute for wheat flour (WF), has gained popularity among consumers in the development of nutritious food products. However, the mechanism of SPF on gluten in dough remains unclear. Effects of SPF on the pasting characteristics, gluten aggregation properties, and the quality of dough were investigated. The results showed that SPF-WF exhibited low pasting properties, and pasting temperature increased by 22.35%–26.98%. SPF-WFs were lower in peak viscosity (62.57%–88.17%), trough viscosity (80.32%–96.67%), breakdown viscosity (11.58%–66.37%), final viscosity (70.72%–96.95%), setback viscosity (57.83%–97.33%), and peak time (16.26%–29.30%). Compared with WF dough, SPF-WF dough had higher hardness and lower elasticity. Microstructure images showed that SPF changed the pore size of the gluten network and caused starch to accumulate. SPF could accelerate gluten aggregation, decrease gluten network strength, and reduce aggregation energy, possibly due to the increase of disulfide bonds from 1.12% to 12.52% (P < 0.05). Moreover, SPF mediated medium molecular weight gluten as well as monomer gluten were polymerized into large molecular weights. In summary, SPF might mediate gluten aggregation and 10% substitution of SPF showed a significant level compared to others. • Enhanced nutrient content and bioactive potential by adding SPF. • Polyphenols in SPF induce disulfide bond formation. • SPF can be cross-linked into the gluten network structure. • The 10% substitution of SPF was determined to be the optimal substitution amount. [ABSTRACT FROM AUTHOR]

Trehalose is widely used in the food and cosmetics industry owing to its unique stabilizing properties. In this study, we aimed to further understand the effect of trehalose on the aggregation and structural properties of gluten. We investigated changes in the aggregation and textural properties, molecular weight distribution, disulfide bond contents, secondary structure, and network structure for weak-, middle-, and strong-gluten when supplemented with trehalose. The results showed that the macromolecular aggregation of gluten proteins was impaired. The hardness, gumminess, and chewiness of dough reduced, whereas adhesiveness increased significantly. Moreover, a looser gluten network structure was obtained with increase in trehalose content. High levels of trehalose (<5%) caused a decrease in the disulfide bond content. Secondary structure analysis of gluten indicated that the α-helix content increased for weak-gluten. In strong-gluten wheat, the β-sheet content was converted to random coil. This suggests that trehalose affected the hydration level of gluten. Trehalose likely competes with gluten for the available water by disrupting the hydrogen bonds between gluten and water molecules and breaking the "loop and train" model of gluten. Thus, the decreased disulfide bond content and increased α-helix and random coil contents induced by trehalose inhibited gluten aggregation and interrupted the gluten network. The study findings improve our understanding of trehalose functionality in dough of different gluten strength. Furthermore, these data provide valuable insights into the application of trehalose in wheat flour food products. [Display omitted] • Macromolecular aggregation of gluten proteins was impaired by trehalose. • Trehalose enhanced the adhesiveness of dough for different gluten strength flour. • High levels of trehalose (exceed 5%) adding caused a decrease of S–S content of gluten. • α-helix and random coil contents of gluten increased as trehalose treated. • A discontinuous gluten network was obtained induced by trehalose. [ABSTRACT FROM AUTHOR]

Reducing sodium in cereal products has become a health trend, and low-sodium salt is considered as a promising sodium substitute; however, its technical roles in dough formation have not been well understood. Effects of low-sodium salt on the physicochemical and rheological properties of dough were investigated in the present study compared with that with NaCl and KCl. Addition of low-sodium salt significantly increased stability, development time and extensional area of dough, and reduced water absorption. Wheat gluten extractability and free SH content gradually decreased with low-sodium salt additions increased, indicating that salt affected gluten macromolecular aggregation. Zeta potential measurements indicated that salt promoted the interactions between gluten molecules. Overall, low-sodium salt effectively changed physicochemical and rheological properties of dough in a manner very similar to NaCl and KCl. Therefore, addition of low-sodium salt may be a feasible approach to alleviate high sodium in the process of dough formation. [Display omitted] • Addition of low-sodium salt increase gluten strength and extensional area. • Addition of low-sodium salt decreased free SH group content. • Low-sodium salt may induce the aggregation of gluten in dough. • Low-sodium salt increases salt-gluten interaction, to some extent. [ABSTRACT FROM AUTHOR]

Pectin is a common food additive used for enhancing the health benefits of dietary fibers, and is the most structurally and functionally complex polysaccharide, rich in galacturonic acid. In this study, we investigated changes in the aggregative property of gluten, their rheological properties, and secondary structure, as well as in the gluten network, when supplemented by apple pectin. Adding pectin was shown to enhance the macromolecular aggregation of gluten, and improved the rheological properties of dough by inducing a dense network of gluten. The presence of pectin decreased α-helix content but increased β-sheet and β-turn structure of gluten, suggesting that pectin affected the hydration level of gluten, leading to the formation of aggregated β-structures. This study provides a better understanding of pectin functionality in wheat flour dough, and is valuable for guiding in the application of pectin in wheat flour food products. [Display omitted] [ABSTRACT FROM AUTHOR]