Small Starch Granules Research Articles

Multi-omics reveals the metabolic changes and genetic basis of post-flowering rice caryopsis under blue light

BackgroundThe effects of blue light on photosynthetic organs have been studied. However, its effects on non-photosynthetic organs, in particular, on the early stages of rice caryopsis development, are unclear. Thus, we aimed to determine the metabolic characteristics of caryopsis development under blue light to improve the metabolic quality of crop kernels.ResultsWe conducted a multi-omics analysis of each of the three periods from the beginning of cellular differentiation to the end of morphogenesis in post-pollination seeds of a japonica rice variety to explore the effect of blue light on metabolic levels during these metabolic changes and its genetic basis. It was found that blue light caused a gradual decrease in auxin content, a significant increase in the accumulation of JA and flavonoids, and a downregulation of the expression of many starch-related genes and proteins, leads to reduced starch synthesis and smaller starch granules. In addition, the gene co-expression network identified three transcription factors that may regulate starch and two that may regulate flavonoids.ConclusionsIt was found through multi-omics testing that hormones such as jasmonic acid and auxins, and metabolites including alkaloids, flavonoids, lipids, organic acids, phenolic acids, and terpenoids altered significantly. Transcriptome and proteome analyses showed that blue light affected the seed nutrient repository activity. Specifically, starch- and gluten-related genes and proteins were significantly downregulated. Co- and WGCNA analyses identified several transcription factors that were regulated under blue light and identified key regulators of starch. Our study provides an understanding of the effects of blue light on post-flowering development in Gramineae and provides a framework for blue light-induced synthesis of secondary metabolites.Graphical

Effects of nitrogen fertilizer application on the physicochemical properties of foxtail millet (Setaria italica L.) starch

The use of nitrogen fertilizer is a crucial agronomic practice to increase crop output and quality. This study investigated the impact of five nitrogen application levels (0, 60, 135, 210, and 285 kg N/hm2) on the physicochemical properties of foxtail millet (FM) starch. Optimal nitrogen application (210 kg N/hm2) significantly increased L*, a*, and b* values, water and oil absorption capacity, water solubility, and swelling power of starch. The number of small starch granules increased as the nitrogen application rate increased, but the granule morphology and typical A-type pattern did not change among the treatments. Nitrogen application increased the relative crystallinity and ordered structure, resulting in a higher gelatinization enthalpy. Compared to the control group (7.02 J/g), the enthalpy increased by 21.94 %, 66.38 %, 73.50 %, and 103.28 % under the nitrogen application rates, respectively. Moreover, nitrogen application greatly increased the percentage of A and B3 chains while it lowered the apparent amylose content, peak viscosity, and final viscosity. The effects of 210 and 285 kg N/hm2 treatments on the water solubility and swelling power, water and oil absorption, and light transmission of starch were greater compared to the 60 and 135 kg N/hm2 treatments. These results indicate that nitrogen fertilization significantly affects the physicochemical properties of FM starch.

Environment found to explain the largest variance in physical and compositional traits in malting barley grain.

Starch is the most abundant constituent (dry weight) in the barley endosperm, followed by protein. Variability of compositional and potentially related physical traits due to genotype and environment can have important implications for the malting and brewing industry. This was the first study to assess the effects of genotype, environment, and their interaction (G × E) on endosperm texture, protein content, and starch traits corresponding to granule size, gelatinization, content, and composition, using a multi-environment variety trial in California, USA. Overall, environment explained the largest variance for all traits (ranging from 23.2% to 76.5%), except the endosperm texture traits wherein the G × E term explained the largest variance (45.0-86.5%). Our unique method to quantify the proportion of fine and coarse milled barley particles using laser diffraction showed a binomial distribution of endosperm texture. The number of small starch granules varied significantly (P-value < 0.05) across genotypes and environments. We observed negative correlations between total protein content and each of enthalpy (-0.70), total starch content (-0.54), and difference between offset and onset gelatinization temperature (-0.52). Furthermore, amylose to amylopectin ratio was positively correlated to volume of small starch granules (0.36). Our findings indicate that environment played a larger role in influencing the majority of starch-related physical and compositional traits. In contrast, variance in endosperm texture was largely explained by G × E. Maltsters would benefit from accounting for environmental contributions in addition to solely genotype when making sourcing decisions, especially with regards to total protein, total starch, enthalpy, and difference between offset and onset gelatinization temperature. © 2024 Society of Chemical Industry.

Changes of crystalline structure and physicochemical properties of Pueraria lobata var. thomsonii starch under water deficit.

Crystal type is an important physicochemical property of starch. However, it is currently unclear whether changes in crystal type affect other properties of starch. This study discovered that water deficit resulted in an increase in small starch granules and transparency in Pueraria lobata var. thomsonii, while causing a decrease in amylose content and swelling power. Additionally, the crystal type of P. Thomsonii starch changed from CB-type to CA-type under water deficit, without significantly altering the short-range ordered structure and chain length distribution of starch. This transformation in crystal type led to peak splitting in the DSC heat flow curve of starch, alterations in gelatinization behavior, and an increase in resistant starch content. These changes in crystalline structure and physicochemical properties of starch granules are considered as adaptive strategies employed by P. Thomsonii to cope with water deficit.

Molecular Basis of the Granular Characteristics of Small-Granule Starch: A Comparative Study.

Small-granule starches (SGSs) have technological advantages over starches of conventional sizes for many applications. The study compared the granular characteristics of three SGSs (from amaranth, quinoa, and taro) with those of maize and potato starches and revealed their molecular basis. The results indicated that the supramolecular architecture of starch granules was not necessarily correlated with granule size. Acid hydrolysis of amaranth and quinoa starches was fast due to not only their small granule sizes but also the defects in the supramolecular structure, to which short external and internal chain lengths of amaranth and quinoa amylopectins contributed. By comparison, the granular architecture of taro starch granules was more stable partly due to the longer external chain length of taro amylopectin. Comparison of the molecular composition of branched subunits (released by using α-amylase of Bacillus amyloliquefaciens) in amylopectins and that in lintnerized starches suggested a significant heterogeneous degradation of amaranth and quinoa starches at supramolecular levels.

Relationship between Chalkiness and the Structural and Physicochemical Properties of Rice Starch at Different Nighttime Temperatures during the Early Grain-Filling Stage.

The chalkiness, starch fine structure, and physiochemical properties of rice starch were analyzed and their correlations were investigated under different nighttime temperatures during the early grain-filling stage. Compared to MT, medium temperature (MT) and low (LNT) and high (HNT) nighttime temperatures resulted in an increased chalky grain rate (CGR) and chalkiness degree (CD). LNT mainly affected the chalkiness by increasing peak1 (short branch chains of amylopectin), the branching degree, and the proportion of small starch granules but decreasing peak2 (long branch chains of amylopectin) and peak3 (amylose branches). This altered the pasting properties, such as by increasing the peak viscosity and final viscosity. However, HNT mainly affected the chalkiness by increasing peak2 and the crystallinity degree but decreasing peak1 and peak3. Regarding the thermal properties, HNT also elevated peak and conclusion temperatures. The CGR and CD were significantly and positively correlated with the proportions of small and medium starch granules, peak1, branching degree, gelatinization enthalpy, setback viscosity, and pasting time but markedly and negatively correlated with the proportion of large starch granules, amylose content, peak3, peak viscosity, and breakdown viscosity. These findings suggest that LNT and HNT disrupted the starch structure, resulting in increased chalkiness. However, their mechanisms of action differ.

A global set of barley varieties shows a high diversity in starch structural properties and related gelatinisation characteristics

The gelatinisation temperature and bimodal granule size distribution of barley starch are important characteristics regarding resource efficiency and product quality in the brewing industry. In this work, the diversity in starch amylose content and granule proportions in a set of modern barley varieties (N = 23) was investigated and correlated with their starch gelatinisation behaviour. Milled barley samples had peak starch gelatinisation temperatures ranging from 60.1 to 66.5 °C. Upon separating the barley starch from the non-starch compounds, sample-dependent decreases in starch gelatinisation temperatures were observed, indicating the importance of differences in barley composition. The peak gelatinisation temperatures of milled barley and isolated barley starches were strongly correlated (r = 0.96), indicating that the behaviour of the starch population is strongly reflected in the measurements performed on milled barley. Therefore, we investigated whether amylose content or starch granule size distribution could predict the gelatinisation behaviour of the starches. Broad ranges in the small starch granule volumes (13.9–32.0 v/v%) and amylose contents (18.2–30.7 w/w%) of the barley starches were observed. For the barley samples collected in the north of the USA (N = 8), the small starch granule volumes correlated positively with the peak gelatinisation temperatures of barley starches (r = 0.90, p < 0.01). The considerable variation in starch properties described in this work highlights that, besides starch content, starch gelatinisation temperature or granule size distribution might provide brewers with useful information to optimise resource efficiency.

Formation of small-granule starch oleogels based on capillary force: Impact of starch surface lipids on lubrication performance

Starch granule oleogels were prepared and their rheological properties were precisely tuned using the capillary bridging phenomenon. The addition of a small amount of water to an oily suspension of starch granules can lead to starch granule bridging and network formation, transitioning it from a fluid-like to a gel-like state. Small-granule starches with high specific surface area and interfacial area exhibited a greater number of liquid bridges and stronger starch granules interactions, making them more prone to forming structurally stable oleogel systems. By increasing the content of water and starch granule, the starch oleogels exhibited three distinct structural states: pendular state (water ≤ 3.28 %, starch ≤ 17.85 %), pendular bridging network (water: 4.92 %, starch: 24.59 %), and capillary aggregates (water ≥ 6.56 %, starch > 24.59 %). Furthermore, the influence of starch granule surface lipids on the lubrication performance of the oleogel system was investigated. Surface roughness increased after extraction of surface lipids, and the friction coefficient also showed a significant increase. Overall, capillary suspension system can potentially be used to design novel fat food products, and our findings have established the correlation between starch granule surface properties and sensory perception in food, providing valuable insights for adjusting the oral processing characteristics of food.

Comparative Study of the Performances of Octenyl Succinic Anhydride‐Modified Agriophyllum squarrosum and Quinoa Starches to Stabilize Pickering Emulsions

AbstractVery small granule starch is a good source for effective Pickering emulsion stabilizers. In this study, native Agriophyllum squarrosum (A. squarrosum) starch (N‐AS) and native quinoa starch (N‐QS) are modified by octenyl succinic anhydride (OSA), and the physicochemical as well as the emulsifying characteristics of two modified starches are evaluated. Fourier transform infrared spectroscopy (FTIR) shows that the esterification reactions between OSA and the two starches are successful, and the substitution effect of OSA‐modified A. squarrosum starch (OSA‐AS) is better than that of OSA‐modified quinoa starch (OSA‐QS). X‐ray diffraction (XRD) analysis shows that OSA modification does not alter the crystal type of the starch particles. OSA modification increases the particle size and hydrophobicity of both starches, and the particles of OSA‐AS are smaller than that of OSA‐QS, which corresponded to the fact that N‐AS possesses a smaller particle size compared to native N‐QS. OSA‐modified starches are arranged at the interface of oil–water to stabilize the emulsion. The OSA‐AS displays better performance of stabilizing emulsion than OSA‐QS. The Pickering emulsions formed by all OSA‐modified starch samples are mainly elastic gel‐like emulsions. In summary, OSA‐AS is more suitable for Pickering emulsion stabilizer than OSA‐QS.

Impact of mutations in starch synthesis genes on morphological, compositional, molecular structure, and functional properties of potato starch.

Morphology, composition and molecular structure of starch directly affect the functional properties. This study investigated the morphological, compositional, and molecular structure properties of starch from starch branching enzyme gene (SBE) and granule-bound starch synthase gene (GBSS) mutated potato, and their associations with thermal, pasting, and film-making properties. SBE mutations were induced in native variety Desiree while GBSS mutations were herestacked to a selected SBE mutated parental line. Mutations in SBE resulted in smaller starch granules and higher amylose content, while GBSS mutations in the SBE background reduced amylose content. Mutations in SBE, particularly with GBSS mutations, significantly increased total phosphorus content. 31P NMR spectroscopy revealed higher proportions of C6-bound phosphate than of C3-bound phosphate in all studied lines. Amylopectin unit chain and internal chain distributions showed higher proportions of long chains in mutated lines compared with Desiree. These amylopectin long-chains were positively correlated with gelatinizationand, pasting temperatures, and temperature at peak viscosity. Short amylopectin chains showed positive correlations with breakdown viscosity, but negative correlations with the crystal melting temperature of retrograded starch. Total phosphorus content was positively correlated with the crystal melting temperature of retrograded starch. Starch from different lines was used to produce a series of potato starch films that differed in morphology and functional properties. A negative correlation was observed between Young's modulus of films and the long amylopectin-chain fraction. Thermal gravimetric analysis revealed highest thermal stability of Desiree starch films, followed by films from SBE-mutated high-amylose lines. Oxygen transmission rate and oxygen permeability analyses showed that films made with starch from selected GBSS and SBEs mutated line maintained comparable oxygen barrier properties to Desiree film. These insights on the impact of genetic mutations on starch properties indicate potential applications of in-planta starch modification for specific end-uses including packaging.

Carotenoid degradation rate in milled grain of dent maize hybrids and its relationship with the grain physicochemical properties

Carotenoids in maize grain degrade during storage, but the relationship between their stability and the physicochemical properties of the grain is unclear. Therefore, the carotenoid degradation rate in milled grain of three dent hybrids differing in grain hardness was evaluated at various temperatures (-20, 4 and 22 °C). The carotenoid degradation rate was calculated using first-order kinetics based on the content in the samples after 7, 14, 21, 28, 42, 56, 70 and 90 days of storage and related to the physicochemical properties of the grain. The highest grain hardness was found in the hybrid with the highest zein and endosperm lipid concentration, while the lowest grain hardness was found in the hybrid with the highest amylose content and the specific surface area of starch granule (SSA). As expected, carotenoids in milled maize grain were most stable at −20 °C, followed by storage at 4 and 22 °C. Tested hybrids differed in the degradation rate of zeaxanthin, α-cryptoxanthin and β-carotene, and these responses were also temperature-dependent. In contrast, all hybrids showed similar degradation rate for lutein and β-cryptoxanthin regardless of the storage temperature. Averaged over the hybrids, the degradation rate for individual carotenoids ranked as follows: lutein < zeaxanthin < α-cryptoxanthin < β-cryptoxanthin < β-carotene. The lower degradation rate for most carotenoids was mainly associated with a higher content of zein and specific endosperm lipids, with the exception of zeaxanthin, which showed an opposite pattern of response. Degradation rate for lutein and zeaxanthin negatively correlated with SSA, but interestingly, small starch granules were positively associated with higher degradation rate for mostcarotenoids. Dent-type hybrids may differ significantly in carotenoid degradation rate, which was associated with specific physicochemical properties of the maize grain.

Mechanistic insights into the enhanced texture of potato noodles by incorporation of small granule starches

Potato noodles are a popular food due to their unique texture and taste, but native potato starch often fails to meet consumer demands for precise textural outcomes. The effect of blending small granule (waxy amaranth, non-waxy oat and quinoa) starch with potato starch on the properties of noodles was investigated to enhance quality of noodles. Morphological results demonstrated that small granule starch filled gaps between potato starch granules, some of which gelatinized incompletely. Meanwhile, XRD and FTIR analysis indicated that more ordered structures and hydrogen bonding among starch granules increased with addition of small granule starch. The addition of oat or quinoa starch increased gel elasticity, decreased viscosity of the pastes, and increased the tensile strength of noodles, while addition of 30 % and 45 % waxy amaranth starch did not increase G′ value of gel or tensile strength of noodles. These results indicated that amylose molecules played an important role during retrogradation, and may intertwine and interact with each other to enhance the network structure of starch gel in potato starch blended with oat or quinoa starch. This study provides a natural way to modify potato starch for desirable textural properties of noodle product.

Morphological, Thermal, and Physicochemical Characteristics of Nano Starch from Cañihua (Chenopodium pallidicaule Aellen)

AbstractThe objective of the study is to determine some physical and thermal properties of Cañihua (Chenopodium pallidicaule Aellen) starch of variety Ramis grown at high altitude. Starch is extracted after hydration of the grains in a solution containing 0.2% SO2 and 0.55% lactic acid for 12 h at 30 °C. Particle Analyzer, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X‐Ray Diffractometry (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Differential Thermogravimetry (DTG), Differential Scanning Calorimetry (DSC), and Rapid Viscosity Analyzer (RVA) are used for characterization. The results show that the starches have a polyhedral shape and 85% have diameters in the range 712–955 nm. Surface agglomerated starches have low roughness values. The XRD shows the characteristic peaks of the starches type A, relative crystallinity of 28.52%, and the transmittance ratio (1045/1022 cm−1) of 1.33 from the FT‐IR. DTG shows three peaks of decomposition (203, 354, and 512 °C) and thermal stability of 251 °C. The temperature and enthalpy change of gelatinization are 62.7 °C and 3.64 J g−1, respectively. The RVA analysis shows viscosity with pasting temperature of 60.2 °C, limited peak viscosity at 95 °C, low breakdown (537 mPa s), and high setback (774.7 mPa s) during cooling. This small granule starch shows potential for applications in the pharmaceutical, cosmetic, chemical, and food industries.

Water management can alleviate the deterioration of rice quality caused by high canopy humidity

This study conducted a two-year field artificial intelligence (AI) greenhouse rice planting experiment with different canopy humidity (normal humidity, NH; high humidity, and HH) and irrigation regimes (continuous flooding, CF; drought cultivation, DC; alternate wetting-drying, AWD) to test whether high canopy humidity from heading to maturity deteriorates rice grain quality, whether appropriate water management can alleviate these adverse effects, and the related mechanisms. The results showed that compared with NH, HH significantly decreased the head rice rate while increasing the protein, amino acid, amylopectin, amylose, and chalkiness. Moreover, HH significantly decreased the peak viscosity, breakdown, and number of small starch granules, while increasing the setback, number of large starch granules, relative crystallinity, gelatinization temperature, and enthalpy. Under NH and HH, AWD treatment resulted in a higher head rice rate, peak viscosity, breakdown, key enzyme activities of starch synthesis, amylose, amylopecan, relative crystallinity, small starch granules, gelatinization temperature, and enthalpy than DC and CF treatments, while lower chalkiness, setback, protein, amino acid, and large starch granules were observed. HH increased the chalkiness by promoting the formation of large starch granules, thus reducing the milling quality. The increase in amylose and relative crystallinity further causes HH to deteriorate the cooking and eating quality. AWD could alleviate the deterioration of rice grain milling, appearance, and eating quality caused by HH by improving starch granules.

Non-Traditional Starches, Their Properties, and Applications.

This review paper focuses on the recent advancements in the large-scale and laboratory-scale isolation, modification, and characterization of novel starches from accessible botanical sources and food wastes. When creating a new starch product, one should consider the different physicochemical changes that may occur. These changes include the course of gelatinization, the formation of starch-lipids and starch-protein complexes, and the origin of resistant starch (RS). This paper informs about the properties of individual starches, including their chemical structure, the size and crystallinity of starch granules, their thermal and pasting properties, their swelling power, and their digestibility; in particular, small starch granules showed unique properties. They can be utilized as fat substitutes in frozen desserts or mayonnaises, in custard due to their smooth texture, in non-food applications in biodegradable plastics, or as adsorbents. The low onset temperature of gelatinization (detected by DSC in acorn starch) is associated with the costs of the industrial processes in terms of energy and time. Starch plays a crucial role in the food industry as a thickening agent. Starches obtained from ulluco, winter squash, bean, pumpkin, quinoa, and sweet potato demonstrate a high peak viscosity (PV), while waxy rice and ginger starches have a low PV. The other analytical methods in the paper include laser diffraction, X-ray diffraction, FTIR, Raman, and NMR spectroscopies. Native, "clean-label" starches from new sources could replace chemically modified starches due to their properties being similar to common commercially modified ones. Human populations, especially in developed countries, suffer from obesity and civilization diseases, a reduction in which would be possible with the help of low-digestible starches. Starch with a high RS content was discovered in gelatinized lily (>50%) and unripe plantains (>25%), while cooked lily starch retained low levels of rapidly digestible starch (20%). Starch from gorgon nut processed at high temperatures has a high proportion of slowly digestible starch. Therefore, one can include these types of starches in a nutritious diet. Interesting industrial materials based on non-traditional starches include biodegradable composites, edible films, and nanomaterials.

Impact of granule-associated lipid removal on the property changes of octenylsuccinylated small-granule starches

Starch granule associated lipids (GALs) are known to alter the properties and functions of small granule starches. To test the hypothesis that the removal GALs from small granule starches could increase the overall reactive surface and improve octenyl-succinylation (OSA) modification efficiency, four small granules starches from rice, oat, quinoa, amaranth and a waxy maize starch were subjected to defat, OSA esterification and combined defatted and OSA treatment. The combined treatment showed a significant improvement in the degree of substitution for all starches from both tritration and 1H NMR methodologies. Confocal microscopy revealed a more uniform distribution of OSA groups on the starch surface. After GALs removal, the bimodal granule size distribution was diminished but reappeared during OSA modification. Pasting viscosity increased for the OSA and GALs removed quinoa, waxy maize and amaranth starches, but it decreased on modified rice and oat starches. OSA treatment alone significantly altered the gelling and rheological properties towards a more soft and less stable starch structure. The combined treatment compensated these changes to some extent and filled the property gap between the native and OSA modified starches. This study demonstrated that removing GALs can achieve more profound OSA derivatization.

Understanding the Relationship between the Molecular Structure and Physicochemical Properties of Soft Rice Starch.

The relationship between the molecular structure and physicochemical properties of soft rice starch (SRS) has been investigated in this research. The amylose content of SRS ranged from 10.76% to 11.85%, classified as the very low amylose type. Compared to waxy and japonica rice starch, the largest amount of small starch granules and the highest viscosity were shown in the SRS. The results of X-ray diffraction and Fourier transform infrared proved that the SRS depicted a typical A-type pattern with a low short-range ordered structure. Additionally, SRS had a great deal of A and B1 chains. Molecular weights and density of starch from soft rice were lower than those from waxy rice but higher than those from japonica rice. Furthermore, SRS possessed a higher amount of resistant starch. Correlation analysis indicated that the amylose content and the chain-length distributions of amylopectin play a major role in influencing the molecular structure and physicochemical properties of rice starch. In conclusion, the low amylose content, highest viscosity, and other excellent properties of soft rice starch make it have bright application prospects in instant rice and rice cakes.

Effects of elevated nitrogen fertilizer on the multi-level structure and thermal properties of rice starch granules and their relationship with chalkiness traits.

Chalkiness in rice reduces its market value and affects consumer acceptance. Research on the mechanism of chalkiness formation has focused primarily on the activity of key enzymes of carbon metabolism and starch accumulation. The relationship between the formation of chalkiness induced by N fertilizer and rice starch's multi-level structure and thermal properties still needs to be fully elucidated. In this study, the rates of chalky grains and degree of chalkiness decreased with the increase in N fertilizer dosage. This was attributed to an increased proportion of short chains, ordered structure carbon chains, small starch granules, and branched starches, and a higher degree of crystallinity and ΔHg in protein, and a decreased proportion of amylose, large starch granules, and weighted average diameter of starch granule surface area and volume. Application of N fertilizer promoted an increased proportion of short-branched chain amylopectin to develop a more ordered carbohydrate structure and crystalline lamella. These effects enhanced the normal development and compactness of starch granules in grains, and improved their arrangement morphology, thereby reducing the chalkiness in rice. These changes in starch multi-level structure and protein improve the physicochemical characteristics of starch and enhance the fullness, crystallinity and compactness of starch granules, while synergistically increasing the regularity and homogeneity of starch granules and thus optimizing the stacking pattern of starch granules, leading to a reduction in rice chalkiness under nitrogen fertilization and thus improving the appearance of rice. © 2023 Society of Chemical Industry.

Impact of long-term ultrasound treatment on structural and physicochemical properties of starches differing in granule size

Granule size is a critical parameter affecting starch processing properties. Ultrasound treatments of up to 22 h were applied on two starches differing in granule size (quinoa starch and maize starch). The two starches showed significantly different trends in both structural and physicochemical aspects affected by the ultrasound treatments. For the small granule starch (volume-weighted mean particle size of 1.79 μm), short-term ultrasonication caused an increase of swelling power. As the treatment time increased, the physicochemical properties were influenced by the degradation of amylopectin external chains. The X-ray diffraction results showed a decrease of relative crystallinity and changes of peak areas with long-term treatment. On the other hand, a balance between amylose leaching and surface damages was seen for the large granule starch (volume-weighted mean particle size of 18.3 μm). The effect of ultrasound modification on starches with different molecular and granular structures was discussed. A possible mechanism of the ultrasound effect was proposed.

Superior gluten structure and more small starch granules synergistically confer dough quality for high amylose wheat varieties.

High amylose wheat (HAW) has potential health benefits but its dough structure is usually inferior. Wheat dough is a complex mixture and its structure is influenced by the physicochemical properties of gluten and starch. In this study, we investigated the starch granule development, gluten structure, starch properties, pasting, and thermal properties of flour, as well as the rheological properties of dough in wheat variety Xinong 836 with high amylose content (33.57%) and its parents. The results showed that Xinong 836 wheat starch contained more small starch granules, which was consistent with the microstructural results of starch granules in grain filling stage. Moreover, Xinong 836 wheat starch showed highest swelling power and water solubility. Importantly, the flour of Xinong 836 wheat had the highest protein content and wet gluten content and Xinong 836 wheat gluten showed highest β-sheets content and disulfide bond content than its parents Zhengmai 7698 and Xinong 979, which conferring to more compact microscopic networks of dough, thereby contributing to the higher peak viscosity (PV), final viscosity (FV), and setback viscosity (SB) in the flour of Xinong 836. Our finding elucidated that the stability of gluten and properties of starch synergistically affected the pasting and thermal properties of the flour paste, and the presence of more small starch granules contributed to dough with a rather dense structure in HAW Xinong 836. Thus, superior gluten structure and more small starch granules have synergistic effects on enhancing the gluten-starch interaction, thereby contributing to better dough quality.