The relation between wheat starch properties and noodle springiness: From the view of microstructure quantitative analysis of gluten-based network

Changes in overall digital structure, starch properties and moisture distribution reveal how the hardness of wheat noodles evolves under different cooking status

To elucidate the relationship between the structural evolution of starch within noodles during cooking and the hardness, the panoramic and local microstructure of cooked noodles were quantitatively analyzed, and the structure of starch in noodles were measured. We found that in the case of starch within cooked noodles with a high degree of swelling, the quantitative analysis of each ring was sufficient to represent the structural differences. Changes occurring in starch inside noodles during cooking were not homogeneous. The structural modifications of starch in the outer ring were greater than in the inner ring along with the extension of cooking time. The main reason responsible for the high hardness was attributed to low swelling degree and high short-range order of starch in the center. Water migration from the periphery to the center of the noodles, which was closely related to the fine structure of amylopectin, determined the state of central starch. Wheat starch with more large amylopectin molecules and more long amylopectin chains could enhance the inhibition of water migration and decrease the swelling degree of starch in the center, in order to endow a high hardness to noodles. These results will be useful for the ingredients selection for the production of noodles with desirable quality. In addition, the analysis method established in this work promoted the realization of quantitative comparison of the cooked noodles microstructure, that is an effective tool to clarify the structural basis of macroscopic quality of noodles.

The effects of adding various starches on the structures of restructured potato-based dough and the oil uptake of potato chips

BACKGROUND

The material composition significantly influences the oil absorption and quality characteristics of fried food products. The oil absorption of restructured potato chips is highly dependent on the structural properties of the restructured potato-based dough produced prior to frying. In this study, three types of starch were added to modify the structure of restructured potato-based dough, allowing the production of potato chips with less oil absorption.

RESULTS

Distinct differences were observed among the three types of starch in terms of amylose content, chain length distribution, swelling power, solubility, crystalline structure and pasting properties. The addition of wheat starch, corn starch and tapioca starch changed the rheological properties, water distribution and strength of the restructured dough. Importantly, adding wheat starch and corn starch significantly lowered the oil content of potato chips by 7.94% and 13.06%, respectively. The reduction in oil absorption by potato chips was attributed to the increased strength of the starchy gel network of the dough, a slower rate of water evaporation and a limitation of dough expansion during frying.

CONCLUSION

Adding wheat starch or corn starch to restructured potato-based dough resulted in a decrease in the oil absorption of potato chips by creating a stronger starchy gel network in the dough. This study could guide the development of suitable material compositions, which are important for producing fried food products with lower oil content. © 2024 Society of Chemical Industry.

Moderate regulation of wheat B-starch ratio: Improvement of molecular structure, spatial conformation, aggregation behavior of reconstituted fermented doughs and its processing suitability

Aiming to investigate the changes and effects of different particle sizes of wheat A/B starch during dough fermentation, the present study reconstituted A/B starch fractions in ratios of 100:0, 75:25, 50:50, 25:75, and 0:100, further blended with gluten and subjected to slight (20 min), medium (30 min), and high (60 min) fermentation processes by yeasts. Results showed that fermentation gas production promoted gluten network extension, inducing starch granule exposure and dough surface roughness. Also, fermentation fractured protein intermolecular disulfide bonds and decreased α-helix and β-folded structure content, contributing to GMP, LPP, and SPP content decreases. Moreover, moderately increasing the B-starch ratio in the dough can improve gluten network stability, continuity, and air-holding capacity. The 25A-75B steam bread exhibited optimal processing suitability (better morphology, texture, and quality) due to its higher GMP and polymer protein content with lower free sulfhydryl and monomeric protein content. Further, conformational relationships indicated the key indicators influencing dough products' properties were free sulfhydryl content, GMP content, protein molecular weight distribution, and secondary structure. The obtained findings contributed to understanding the effect of wheat starch granule size distribution on dough processing behavior, and future targeted breeding for wheat cultivars with high B-starch content for improved fermentation pasta product qualities.

Effects of improver on the quality of frozen Chinese sweet rice wine dough: Water status, protein structure and flavor properties

In the study, a sweet wine koji (YQ-5) was successfully selected to make frozen Chinese sweet rice wine dough (F-CD) for flavor enrichment. Subsequently, the effects of single improver (SI: xanthan gum, potassium carbonate, antifreeze protein, diacetyl tartaric esters of monoglycerides and composite improver (XPADG: Four improvers mixed in proportion) on the texture, rheological properties, microstructure, water status, protein secondary structure, volatile flavor substances and sensory properties of F-CD during frozen storage were investigated. The results indicated that XPADG slowed the increase in freezable water and water mobility in the dough, giving dough the most stable rheological properties and minimizing the damage of freezing to the secondary structure and microstructure of proteins. Besides, GC-QTOF/MS analysis showed that XPADG may facilitate the retention of flavoring substances in F-CD after storage for 6 days. Finally, the sensory evaluation showed that XPADG imparted good sensory properties to the product after freezing for 6 days.

Effect of oxidized starch on the storage stability of frozen raw noodles: Water distribution, protein structure, and quality attributes

Freezing is a popular method of food preservation with multiple advantages. However, it may change the internal composition and quality of food. This study aimed to investigate the effect of modified starch on the storage stability of frozen raw noodles (FRNs) under refrigerated storage conditions. Oxidized starch (OS), a modified starch, is widely used in the food industry. In the present study, texture and cooking loss rate analyses showed that the hardness and chewiness of FRNs with added OS increased and the cooking loss rate decreased during the frozen storage process. Low-field nuclear magnetic resonance characterization confirmed that the water-holding capacity of FRNs with OS was enhanced. When 6% OS was added, the maximum freezable water content of FRNs was lower than the minimum freezable water content (51%) of FRNs without OS during freezing. Fourier-transform infrared spectroscopy showed that after the addition of OS, the secondary structures beneficial for structural maintenance were increased, forming a denser protein network and improving the microstructure of FRNs. In summary, the water state, protein structure, and quality characteristics of FRNs were improved by the addition of OS within an appropriate range.

Anionic starch-based hybrid cryogel-embedded ZnO nanoparticles: tuning the elasticity and pH-functionality of biocomposites with dicarboxylic acid units

Weakly anionic semi-interpenetrating polymer network (semi-IPN) biocomposites based on starch (ST)-incorporated poly(acrylamide-co-itaconic acid)/ZnO (ST-PAI/ZnO) were synthesized by a simple one-pot method via free radical aqueous polymerization. Hybrid biocomposites exhibited lower equilibrium swelling compared with neat copolymer gel. For both hydrogels and cryogels, swelling followed a decreasing order as copolymer PAI > starch-free PAI/ZnO > ST-PAI/ZnO gels. With the addition of 9% ST and ZnO, the swelling ratio of gels decreased from 898 to 68.3, resulting in a significant increase in elastic modulus. Compared with a fixed amount of ST, biocomposite cryogels exhibited significantly higher modulus than hydrogels. With the addition of 9% ST, the elastic modulus of cryogels reached 22.2 kPa while it was 2.7 kPa for the hydrogels. An equation expressing the effective cross-linking density of semi-IPNs presented by a cubic polynomial as a function of starch was obtained. As pH increased with the presence of dicarboxylic acid units, a gradual increase in swelling occurred at two different pH values. A gradually reproducible swelling change of semi-IPNs was depicted with pH ranging from 2.1 to 11.2. Biocomposite cryogels showed rapid swelling in a buffer solution of pH 11.2 and rapid shrinking in pH 2.1. Salt-induced swelling testing showed that the ability to reduce the degree of swelling and solubility of starch was Br- > Cl- > NO3- > SO42- for anions consistent with the Hofmeister series. Adsorption efficiency for the removal of methyl violet (MV) dye was analyzed using Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherm models. The results confirmed that the Langmuir isotherm and pseudo-second-order model are suitable for describing MV adsorption on semi-IPN biocomposites. The synthesized biocomposites with good swelling/deswelling kinetics in different pH-buffer solutions, high saline absorbency, desirable adsorption efficiency, and acceptable pH-dependent swelling reversibility can be considered as smart hybrid materials for the adsorption of the dye in water purification tasks.

Effect of osmotic pressure and simultaneous heat-moisture phosphorylation treatments on the physicochemical properties of mung bean, water caltrop, and corn starches

This study aimed to investigate the physicochemical properties of modified starch prepared through the simultaneous heat-moisture and phosphorylation treatment (HMPT) and osmotic pressure treatment (OPT) for water caltrop starch (WCS), mung bean starch (MBS), and amylose-rich corn starch (CS) for different time periods. Furthermore, variations in starch content [amylose and resistant starch (RS)], swelling powder (SP), water solubility index (WSI), crystallinity, thermal properties, gelatinization enthalpy (ΔH), and glycemic index (GI) were examined. This study demonstrates that neither HMPT nor OPT resulted in a significant increase in the resistant starch (RS) content, whereas all samples succeeded in heat-treating at 105 °C for another 10 min exhibited a significant increase in RS content compared to their native counterparts. Moreover, the gelatinization temperatures of the three starches increased (To, Tp, and Tc), whereas their gelatinization enthalpy (ΔH) and pasting viscosity decreased. In particular, the GI of all three modified starches subjected to HMPT or OPT showed a decreasing trend with modification time, with OPT exhibiting the best effect. Therefore, appropriate modification through HMPT or OPT is a viable approach to develop MBS, WCS, and CS as processed foods with low GI requirements, which exceptionally may be suitable for canned foods, noodles, and bakery products.

Explaining the improving effect of dough crumb-sheet composite rolling on fresh noodle quality: From microstructure and moisture distribution perspective

A new technique known as dough crumb-sheet composite rolling (DC-SCR) was used to improve the quality of fresh noodles. However, there is a dearth of theoretical investigations into the optimal selection of specific parameters for this technology, and the underlying mechanisms are not fully understood. Therefore, the effects of dough crumb addition times in DC-SCR on the texture, cooking, and eating quality of fresh noodles were first studied. Then, the underlying regulation mechanism of DC-SCR technology on fresh noodles was analyzed in terms of moisture distribution and microstructure. The study demonstrated that the most significant enhancement in the quality of fresh noodles was achieved by adding dough crumbs six times. Compared with fresh noodles made without the addition of dough crumbs, the initial hardness and chewiness of fresh noodles made by adding six times of dough crumbs increased by 25.32% and 46.82%, respectively. In contrast, the cooking time and cooking loss were reduced by 28.45% and 29.69%, respectively. This quality improvement in fresh noodles made by DC-SCR came from the microstructural differences of the gluten network between the inner and outer layers of the dough sheet. A dense structure on the outside and a loose structure on the inside could endow the fresh noodles made by DC-SCR with higher hardness, a shortened cooking time, and less cooking loss. This study would provide a theoretical and experimental basis for creating high-quality fresh noodles.

A Review of the Impact of Starch on the Quality of Wheat-Based Noodles and Pasta: From the View of Starch Structural and Functional Properties and Interaction with Gluten

Starch, as a primary component of wheat, plays a crucial role in determining the quality of noodles and pasta. A deep understanding of the impact of starch on the quality of noodles and pasta is fundamentally important for the industrial progression of these products. The starch structure exerts an influence on the quality of noodles and pasta by affecting its functional attributes and the interaction of starch-gluten proteins. The effects of starch structure (amylopectin structure, amylose content, granules size, damaged starch content) on the quality of noodles and pasta is discussed. The relationship between the functional properties of starch, particularly its swelling power and pasting properties, and the texture of noodles and pasta is discussed. It is important to note that the functional properties of starch can be modified during the processing of noodles and pasta, potentially impacting the quality of the end product, However, this aspect is often overlooked. Additionally, the interaction between starch and gluten is addressed in relation to its impact on the quality of noodles and pasta. Finally, the application of exogenous starch in improving the quality of noodles and pasta is highlighted.

Effect of dynamic high-pressure treatments on the multi-level structure of starch macromolecule and their techno-functional properties: A review

Over the past decades, dynamic high-pressure treatment (DHPT) executed by high-pressure homogenization (HPH) or microfluidization (DHPM) technology has received humongous research attention for starch macromolecule modification. However, the studies on starch multi-level structure alterations by DHPT have received inadequate attention. Furthermore, no review comprehensively covers all aspects of DHPT, explicitly addressing the combined effects of both technologies (HPH or DHPM) on starch's structural and functional characteristics. Hence, this review focused on recent advancements concerning the influences of DHPT on the starch multi-level structure and techno-functional properties. Intense mechanical actions induced by DHPT, such as high shear and impact forces, hydrodynamic cavitation, instantaneous pressure drops, and turbulence, altered the multi-level structure of starch for a short duration. The DHPT reduces the starch molecular weight and degree of branching, destroys short-range ordered and long-range crystalline structure, and degrades lamellar structure, resulting in partial gelatinization of starch granules. These structural changes influenced their techno-functional properties like swelling power and solubility, freeze-thaw stability, emulsifying properties, retrogradation rate, thermal properties, rheological and pasting, and digestibility. Processing conditions such as pressure level, the number of passes, inlet temperature, chamber geometry used, starch types, and their concentration may influence the above changes. Moreover, dynamic high-pressure treatment could form starch-fatty acids/polyphenol complexes. Finally, we discuss the food system applications of DHPT-treated starches and flours, and some limitations.

Characterization of a Novel Starch Isolated from the Rhizome of Colombian Turmeric (Curcuma longa L.) Cultivars

Turmeric (Curcuma longa L.) plants are native to Southeast Asia and are part of the Zingiberaceae family. Global consumption and production of this plant are expanding. In countries such as Colombia, turmeric is a promising cultivar. Curcuminoids derived from its rhizomes are used in food, pharmaceuticals, and natural cosmetics. Curcuminoids constitute approximately 3 wt% of the rhizome. Many residues rich in cellulose and starch can thus be recovered. This study characterizes a novel starch isolated from Colombian turmeric cultivars. The morphological parameters of the starch were determined using microscopic techniques such as scanning electron microscopy (SEM). Proximate analysis and infrared spectroscopy (ATR-FTIR) were used to analyze the chemical composition, while physical analyses included thermal characterization, swelling power testing, solubility, water retention capacity, and colorimetry evaluation. The new starch granules were ellipsoidal in shape and ranged in diameter from 19.91 to 38.09. A trace amount of remaining curcumin was identified through chemical and physical characterization. The swelling power was 3.52 ± 0.30, and its water retention capacity was 3.44 ± 0.30. Based on these findings, turmeric can be useful in both food and non-food applications. Because starch was extracted from other Zingiberaceae plants, this study also includes a brief review of the related literature.

A review of starch swelling behavior: Its mechanism, determination methods, influencing factors, and influence on food quality

Swelling behavior involves the process of starch granules absorbing enough water to swell and increase the viscosity of starch suspension under hydrothermal conditions, making it one of the important aspects in starch research. The changes that starch granules undergo during the swelling process are important factors in predicting their functional properties in food processing. However, the factors that affect starch swelling and how swelling, in turn, affects the texture and digestion characteristics of starch-based foods have not been systematically summarized. Compared to its long chains, the short chains of amylose easily interact with amylopectin chains to inhibit starch swelling. Generally, reducing the swelling of starch could increase the strength of the gel while limiting the accessibility of digestive enzymes to starch chains, resulting in a reduction in starch digestibility. This article aims to conduct a comprehensive review of the mechanism of starch swelling, its influencing factors, and the relationship between swelling and the pasting, gelling, and digestion characteristics of starch. The role of starch swelling in the edible quality and nutritional characteristics of starch-based foods is also discussed, and future research directions for starch swelling are proposed.

The Role of Gluten in Food Products and Dietary Restriction: Exploring the Potential for Restoring Immune Tolerance

Wheat is extensively utilized in various processed foods due to unique proteins forming from the gluten network. The gluten network in food undergoes morphological and molecular structural changes during food processing, affecting the final quality and digestibility of the food. The present review introduces the formation of the gluten network and the role of gluten in the key steps of the production of several typical food products such as bread, pasta, and beer. Also, it summarizes the factors that affect the digestibility of gluten, considering that different processing conditions probably affect its structure and properties, contributing to an in-depth understanding of the digestion of gluten by the human body under various circumstances. Nevertheless, consumption of gluten protein may lead to the development of celiac disease (CD). The best way is theoretically proposed to prevent and treat CD by the inducement of oral tolerance, an immune non-response system formed by the interaction of oral food antigens with the intestinal immune system. This review proposes the restoration of oral tolerance in CD patients through adjunctive dietary therapy via gluten-encapsulated/modified dietary polyphenols. It will reduce the dietary restriction of gluten and help patients achieve a comprehensive dietary intake by better understanding the interactions between gluten and food-derived active products like polyphenols.

Cantilever beam bending as a potential method to determine the elasticity of cooked Udon noodles

Elasticity is a critical measure of the eating quality of Udon noodles. To characterize the elasticity of Udon noodles, an instrumental method based on the cantilever beam bending test was established. Firstly, the optimum test parameters were determined. Then, texture profile analysis, compression, tension, and cantilever beam bending methods were used to measure the elasticity of 25 commercial Udon noodles with different shapes and sizes, and the correlations between elasticity obtained by the above instrumental methods and sensory evaluation were analyzed. Finally, how the shape and size of Udon noodles influenced their elasticity was discussed in detail. Within the deflection of 2.0 mm, the force increased approximately linearly with increasing deflection, and moderate loading speed (0.5-1.0 mm/s) should be used in the cantilever beam bending experiments to improve the accuracy of results. The bending stiffness obtained by the cantilever beam bending method exhibited a higher coefficient of variation and stronger correlation with the elasticity of sensory evaluation than other instrumental methods. Furthermore, the Udon noodle sample with a higher size, especially the thickness, had higher elasticity, and the Udon noodle sample with a rectangular cross-section showed higher elasticity than that with a circular cross-section. In conclusion, the bending stiffness determined by the cantilever beam bending method could be used to characterize the elasticity of cooked Udon noodles.

Investigating the positive effects of wrap-around resting on the qualities of semi-dried noodles through the quantitative analysis of gluten network

In this study, the dough sheet wrap-around was employed to assist the resting process of the semi-dried noodles comparatively with dough crumbs resting and common dough sheet resting. The gluten network quantitative analysis was carried out to investigate the positive impacts of dough sheet wrap-around resting in semi-dried noodles production. The results showed that the dough sheet wrap-around resting improved the color, surface smoothness, cooking qualities, and eating qualities of semi-dried noodles. Dough sheet wrap-around resting for 30 min significantly (p < 0.05) increased the surface smoothness and chewiness by 47.08% and 44.35%, respectively. Furthermore, increased extensibility in the transverse direction of dough sheets generated superior processing properties. The average protein length and width of dough sheets experienced a considerable (p < 0.05) reduction. In contrast, the branching rate was markedly (p < 0.05) augmented, which meant the distribution of gluten network was more uniform and denser. The total protein length and the number of protein network lines both significantly (p < 0.05) increased. The number of transverse protein network lines increased by 28.70%, which was much higher than that (5.77%) of the longitudinal direction. Conclusively, at the optimal dough sheet wrap-around time of 30 min, the higher-quality semi-dried noodles were produced by enhancing the gluten network.

Synergistic effect of endogenous gluten and oleic acid on wheat starch digestion by forming ordered starch-fatty acid-protein complexes during thermal processing

The aim of this study was to understand the potential of endogenous gluten inhibiting the digestibility in vitro of wheat starch (WS) in starch-fatty acid-protein system. Therefore, the influences of gluten and whey protein isolate (WPI) on the properties, multi-scale structure and in vitro digestibility of WS in WS-oleic acid (OA)-protein system were compared. The results of digestibility in vitro indicated that the ternary system of starch-fatty acid-protein showed higher resistant starch (RS) content as well as lower rapidly digestible starch (RDS) content than the binary system of WS-OA, demonstrating protein decreased WS digestion of WS-OA system. The results of pasting properties showed that gluten and WPI both increased the viscosities of WS-OA system during the cooling period due to the formation of WS-OA-protein ternary complex. The results of swelling power and solubility analysis showed that gluten and WPI both decreased the swelling power and solubility of WS-OA binary system. Laser Confocal Raman and X-ray diffraction (XRD) studies indicated that gluten and WPI both increased the ordered degree of WS-OA binary system by decreasing the full width at half maximum (FWHM) of the peak at 480 cm^-1 and increasing crystallinity degree. Strikingly, compared with WPI, gluten had greater effects on the digestibility in vitro, pasting properties and ordered degree of WS in WS-OA-protein system. Therefore, gluten as an endogenous protein has the potential application in reduction the enzymatic digestibility of WS by regulating the reassembly of starch and fatty acid during thermal processing.

Study on the quality characteristics of hot-dry noodles by microbial polysaccharides

The effect of curdlan gum (CG), gellan gum (GG), and xanthan gum (XG) on the quality characteristics of hot-dry noodles (HDN) was investigated. The rheology properties were used to evaluate the quality of the dough, the textural, viscosity, cooking characteristics and water states were investigated to study the quality changes of HDN. Three microbial polysaccharides were found that it could improve the quality of wheat flour and significantly increase the starch viscosity of HDN and delay the water migration rate of HDN. When 0.2% CG, 0.5% GG, and 0.5% XG were added, the HDN showed the best flour swelling power, texture, and tensile properties, and the structure of gluten network was significantly improved. The flourier transform infrared spectroscopy results showed that microbial polysaccharides with appropriate concentrations changed the formation of hydrogen bond in HDN, decreased α-helix and increased β-turn content. Meanwhile, the relative continuous and complete gluten network was formed, which could be proven by microstructure observation. This study provides a reference for functionality applications of HDN with microbial polysaccharides.