Amylose Content Research Articles

Genetic improvement of eating and cooking quality of rice cultivars in southern China.

The genetic improvement of rice eating and cooking quality (ECQ) is an important goal in rice breeding. It is important to understand the genetic regulation of ECQ at the genomic level for effective breeding to improve ECQ. However, the mechanisms underlying the improvement of ECQ of indica and japonica cultivars in southern China remain unclear. In this study, 290 rice cultivars (155 indica and 135 japonica cultivars) bred in southern China in the past 30 years were collected. Physicochemical indicators, namely, apparent amylose content (AAC), protein content (PC), lipid content and taste value, were measured and correlation analysis was performed. Adecrease in AAC and PC was a crucial factor for the ECQ improvement of the rice cultivars in southern China. Genome-wide association analysis and selective domestication analysis preliminarily clarified that the comprehensive utilization of major and minor genes was an important genetic basis for improvement of ECQ. An elite allele, RAmy1AA, with potential application in breeding to improve starch viscosity characteristics and ECQ, was mined. The Wxb/OsmtSSB1LT/OsDML4G/RPBFT/Du3T and Wxb/OsEro1T/Glup3G/OsNAC25G/OsBEIIbC/RAmy1AA/FLO12A gene modules, neither of which have been widely used, are proposed as the optimal allele combinations for ECQ improvement of indica and japonica cultivars in southern China. The results clarify the genetic regulation of rice ECQ improvement in southern China and provide novel genetic resources and breeding strategies for ECQ improvement in rice.

Evaluation of the performance of low-fat (oil-fat) dressings based on chemically modified Guayabo plantain starch (Musa paradisiaca L.).

Guayabo plantain (GP) starch was chemically modified by acetylation to evaluate its role as a stabilizer and emulsifier in low-fat dressings. Native starch (NS) from GP was chemically modified starch (MS), and its functional properties, such as water absorption index, water solubility index, swelling power, gelatinization temperature (Tg), were evaluated. Additionally, functional groups and morphology were identified using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy. Low-fat dressings were prepared using NS and MS at two concentrations, 2% and 3% (NS2, NS3, MS2, MS3), and the stability of the dressings was evaluated over a storage period of 28 days at 4 °C ± 2.0 °C. The percentage of acetylation and the degree of substitution obtained were 2.48% and 0.01, respectively, complying with current regulations. MS showed a higher amylose content (23.62 ± 1.89%) than NS (16.01 ± 0.43%). The Tg of MS decreased, and the appearance of bands at 1012 and 1723 cm-1 in the FT-IR spectra suggested a modification in the functional characteristics of starch due to acetylation. Emulsions of MS at 2% and 3% (MS2 and MS3) showed a smaller droplet size and higher interfacial dispersion. However, MS3 had higher viscosity, which contributed to an increase in hydrophobicity and delays in flocculation and subsequent coalescence. This research study provides useful information on the use of 3% MS dressings in new food formulations, reducing fat content while preserving functional characteristics, thus ensuring greater stability.

The Synergistic Optimization of Rice Yield, Quality, and Profit by the Combined Application of Organic and Inorganic Nitrogen Fertilizers

The replacement of urea with polymer-coated urea (PCU) fertilizer and the application of organic fertilizers (OFs) are effective strategies for reducing N loss in farmland and preventing soil degradation. However, limited research has been conducted on the synergistic effects of OF combined with inorganic N fertilizer, particularly PCU, on rice yield, quality, and profit. To address this issue, a two-year field experiment was conducted involving five fertilization treatments: no nitrogen fertilizer (0N), urea applied at the full local rate of 270 kg N ha−1 (CK), PCU at a reduced rate of 240 kg N ha−1 (T1), a combination of 70% PCU and 30% urea at 240 kg N ha−1 (T2), and T2 supplemented with 4500 kg ha−1 of OF (T3). The results showed that, compared with CK, the T1 treatment improved the appearance quality and taste value but slightly reduced the other quality indices. In contrast, the T2 and T3 treatments enhanced the grain yield, especially for T3, with an advantage in the tiller number, shoot dry weight, and leaf area index, which promoted the panicle number, filled grain, and grain weight, thereby significantly increasing the yield. The T2 improved the processing, appearance, and taste qualities by reducing the protein content, increasing the amylose content and gel consistency, and optimizing the starch viscosity characteristics (increasing the peak viscosity and breakdown while reducing the setback and consistency), with the addition of OF (T3) further expanding the benefits. Furthermore, the nutritional quality was also enhanced by optimizing the protein components and increasing the protein yield. Although the agricultural inputs in the T2 and T3 treatments were higher, the profit from the increased grain yield could cover these inputs, thereby maintaining profit with T3 or increasing profit with T2. In summary, the combined application of PCU with urea and OF can synergistically improve the rice yield, quality, and profit.

Comparative Analysis of Photosynthetic Traits, Yield, and Fruit Quality Among Different Chestnut Cultivars

This study aimed to compare the photosynthetic physiological traits, fruiting characteristics, and fruit quality of four different chestnut cultivars. The cultivars studied were ‘Yanshanzaofeng’ (YS), ‘Guangdedahongpao’ (GD), ‘Chang’anhuijianli’ (CA), and ‘Guizhouyouli’ (GZ). Leaf functional traits, photosynthetic activity, fruit setting characteristics, and both external and internal fruit quality indicators were measured. The results indicated significant differences in leaf traits among cultivars. Cultivar GD exhibited the largest leaf area and dry matter content, while cultivar GZ had the smallest. The photosynthetic rate (Pn) followed a bimodal curve, with an obvious ‘lunch break’ caused by stomatal limitations. Cultivar GD had the highest Pn, followed by CA, YS, and GZ. The water use efficiency (WUE) and CO2 utilization of cultivar CA were notably superior, indicating its suitability for arid conditions. In terms of yield, cultivar GD had the highest bur, nut weight, and plant yield, followed by CA, YS, and GZ. The phenotypic quality of the fruit was also superior in cultivar GD. However, cultivar YS had the highest amylopectin and soluble sugar content, and cultivar GD had the greatest amylose, total starch, and fat content. Cultivars CA and YS exhibited better overall fruit quality than GZ. Correlation analysis revealed that single bur weight, single nut weight, and single plant yield all exhibited highly significant or significant positive correlations with Pn, stomatal conductance (Gs), intercellular CO2 concentration (Ci), and the transpiration rate (Tr). The longitudinal diameter of burs showed a significant positive correlation with vitamin C (Vc), Pn, and Gs, with a correlation coefficient of 0.99. Additionally, both the transverse and longitudinal diameters of nuts were significantly positively associated with Pn and Ci. Furthermore, the total starch content and water content of nuts demonstrated a significant positive correlation with Pn. In conclusion, cultivar GD was found to be ideal for high-yield starch production, while cultivar YS offers superior sweet and waxy nut qualities. Cultivar CA presents a balance of photosynthetic capacity, yield, and quality, making it the second-best candidate. Cultivar GZ is unsuitable for large-scale cultivation.

ABA Affects Distinctive Rice Caryopses Physicochemical Properties on Different Branches

Abscisic acid (ABA) plays an important regulatory role in the grain filling process, which in turn will affect the final yield and quality of rice. The ABA biosynthesis genes of OsNCED3 and degradation gene OsABA8ox3 affect the ABA content, and then further regulate the ABA signaling. During the development of rice panicle, compared with primary grains (superior grains) growing on primary branches, secondary grains (inferior grains) growing on secondary branches exhibit characteristics. However, little is reported on the physicochemical characteristics of starch between superior and inferior grains in ABA related transgenic lines. In this study, OsNCED3 and OsABA8ox3 transgenic plants were used as materials. The results showed that compared with the WT, the OsNCED3-RNAi lines on grain weight was consistent with the trend of superior and inferior grains, while the OsABA8ox3-RNAi lines affected superior or inferior grains. The total starch and soluble sugar content of grains decreased in both OsNCED3-RNAi and OsABA8ox3-RNAi lines, and the total starch content of superior and inferior grains in OsABA8ox3-RNAi lines decreased. The starch granule size distribution of all samples showed a bimodal and increased proportion of starch grains with large granule size, in which the influence on inferior grains was greater than that of superior grains, which eventually led to a significant increase in their average granule size. The apparent amylose content of inferior grains increased significantly in most lines. The swelling power of the superior grains decreased significantly, while that of the inferior grains increased significantly. Fourier analysis showed that the order degree of starch granule surface decreased in the superior grains of the RNAi line, while it increased in the inferior grains of the OsABA8ox3-RNAi line but decreased in the OsNCED3-RNAi lines. In the superior grains, the relative crystallinity of starch decreased in the OsNCED3-RNAi lines, but remained unchanged or increased in the OsABA8ox3-RNAi line. In inferior grains, the relative crystallinity of starch decreased in the ABA synthesis RNAi line, but increased in the OsABA8ox3-RNAi line. In summary, the influence of ABA on the physicochemical properties of inferior grains is greater than that of superior grains.

A study on the changes in rice composition under reduced fertilization conditions using Raman spectroscopy technology

The substitution of microbial fertilizer for chemical fertilizer can not only improve soil fertility but also effectively enhance rice quality. To investigate the effect of different amounts of combined application of chemical fertilizer and microbial fertilizer on the amylose content of rice, this study adopts theoretical calculations to compare the preprocessed Raman spectroscopy information of rice with reduced fertilization and establishes a recognition model for the amylose content of rice, which is used to detect the amylose content in rice. Based on the amylose spectral values measured by Raman spectroscopy and the known starch structure and functional groups, the Raman peaks are mainly distributed in the range of 400 cm− 1 to 1400 cm− 1. The Raman characteristic peaks at 483 cm− 1, 869 cm− 1, 933 cm− 1, 1082 cm− 1, 1126 cm− 1, 1335 cm− 1, 1385 cm− 1, and 1455 cm− 1 exhibit strong vibration modes, which are consistent with its main nutrient component of amylose. By comparing the measured amylose content in the regions treated with microbial fertilizer combined with different amounts of reduced fertilization and the spectral intensity values of amylose measured by Raman spectroscopy, the results show that the treatment of combining conventional amounts of microbial fertilizer with different amounts of reduced chemical fertilizer exhibits a decreasing trend in the amylose content of rice.

Reducing amylose content in wheat (Triticum aestivum L.) using a novel Wx-D1 null allele generated by chemical mutagenesis.

Amylose has a major influence over starch properties and end-use quality in wheat. The granule-bound starch synthase I, encoded by Wx-1, is the single enzyme responsible for amylose synthesis. Natural null mutants of Wx-1 appear at extremely low frequencies, particularly in the Wx-D1 locus, where only four spontaneous null variants have been identified, with different geographic origins. The current study identified an induced Wx-D1 null mutant (M4-9484) from the M4 generation of an ethyl methanesulfonate-mutagenized population of wheat cv. 'SM126'. The sequencing showed that the complete Wx-D1 ORF sequences of 'SM126' and M4-9484 were 2862 bp long and that there was one SNP mutation between them. The mutation was located at the RNA splice site within the junction of exon 8 and intron 8, which led to abnormal transcription of Wx-D1, with five different aberrant transcripts being identified in the mutant. The Wx-D1 null allele resulted in amylose and total starch content being decreased in M4-9484 in comparison with the wild-type 'SM126', with higher swelling capacity and being fully pasted at higher temperatures than the wild-type parent. The mutation of the Wx-D1 null gene affects the formation of amylose directly, resulting in significantly altered starch properties. This discovery offers valuable insights for enhancing wheat starch quality and contributes to the diversification of starch characteristics. It also deepens our understanding of the genetic and molecular mechanisms underlying amylose synthesis, thereby supporting breeding programs. © 2024 Society of Chemical Industry.

Genome-Wide Analysis of Heat Shock Protein Family and Identification of Their Functions in Rice Quality and Yield

Heat shock proteins (Hsps), acting as molecular chaperones, play a pivotal role in plant responses to environmental stress. In this study, we found a total of 192 genes encoding Hsps, which are distributed across all 12 chromosomes, with higher concentrations on chromosomes 1, 2, 3, and 5. These Hsps can be divided into six subfamilies (sHsp, Hsp40, Hsp60, Hsp70, Hsp90, and Hsp100) based on molecular weight and homology. Expression pattern data indicated that these Hsp genes can be categorized into three groups: generally high expression in almost all tissues, high tissue-specific expression, and low expression in all tissues. Further analysis of 15 representative genes found that the expression of 14 Hsp genes was upregulated by high temperatures. Subcellular localization analysis revealed seven proteins localized to the endoplasmic reticulum, while others localized to the mitochondria, chloroplasts, and nucleus. We successfully obtained the knockout mutants of above 15 Hsps by the CRISPR/Cas9 gene editing system. Under natural high-temperature conditions, the mutants of eight Hsps showed reduced yield mainly due to the seed setting rate or grain weight. Moreover, the rice quality of most of these mutants also changed, including increased grain chalkiness, decreased amylose content, and elevated total protein content, and the expressions of starch metabolism-related genes in the endosperm of these mutants were disturbed compared to the wild type under natural high-temperature conditions. In conclusion, our study provided new insights into the HSP gene family and found that it plays an important role in the formation of rice quality and yield.

Impact of debranning on the nutritional, cooking, microstructural characteristics of five Indian small millets

BackgroundMillets are underutilized grains rich in nutrients. This study aimed to investigate the impact of debranning on the nutritional, cooking, and microstructural properties of five Indian millets namely foxtail, little, kodo, barnyard, and proso millet.MethodsThe proximate composition, mineral content, cooking properties (cooking time, solid loss, water uptake, alkali score), Fourier Transform Infra Red (FTIR) spectra, X ray Diffraction (XRD) and microstructural characteristics (Scanning Electron Microscopy) of dehusked and debranned millet samples were examined and analysed.ResultsDebranning resulted in decrease in protein (except for little and barnyard millets), dietary fibre, fat, mineral and phytate content in all the millets while enhanced available carbohydrates and amylose content. The cooking times for dehusked millets were significantly higher while, the solid loss and water uptake during cooking of debranned millets were higher. On debranning, Fourier Transform Infra Red (FTIR) spectra showed changes in the pattern with increase in the intensity of amide II (1363 to 1367 cm−1) and amide III (1215 to 1231 cm−1) bands in the debranned foxtail, little, and kodo millets. The X-ray diffractogram (XRD) showed decrease in relative crystallinity on debranning. Scanning Electron Microscopic (SEM) examination revealed that debranning resulted in the loss of seed coat, aleurone layer and partial loss of germ in the millets.ConclusionDehusked millets are nutritious and should be promoted in Indian diets to improve diet quality, debranned millets are nutritionally inferior, can increase the glycemic load of Indian diets.

Changes in starch properties during malting and their correlations with the malting quality of multiple barley cultivars

AbstractBackground and ObjectiveThere is still a lack of information about detailed dynamic changes in starch properties during malting among multiple barley varieties and correlations of starch properties with malting qualities. In this work, compositional, physicochemical, morphological, and structural properties of starches from four barley varieties at six time points across the malting process were first investigated to better understand the starch modification of barley malting. Furthermore, a total of 30 barley varieties were used to investigate the relationship between malting qualities and starch properties. The results provide a reference for breeding high‐malting quality barley based on starch properties.FindingsSignificant decreases in starch contents, paste viscosities, relative crystallinity, as well as the ratio of 1045/1022 cm−1 of starch, were exhibited, while comparatively small changes were found in the thermal parameters during malting. Amylose and amylopectin polymers were both hydrolyzed in malting. After malting, pits and holes were discovered on the surface of some starch granules. Four parameters of peak viscosity (PV), breakdown, peak time (PeT), and pasting temperature (PT) had significant correlations with diastatic power (DP), while the above four indicators together with amylose content, total starch content, onset temperature, peak temperature, and swelling power had significant correlations with malt extract (ME).ConclusionsThe trend of changes in starch properties among all four genotypes was similar. However, the variety with better malting quality showed a greater degree of measurements in some starch characters. Starch properties are mainly related to the two malting quality indicators of DP and ME.Significance and NoveltyPV, breakdown, PeT, and PT had significant correlations with malting qualities.

Starch and Protein Characteristics of Chestnut Flours and Their Applications in Gluten-Free Products.

In the context of valorizing underutilized crops, this study investigated the starch and protein characteristics of chestnut varieties (Balestrera and Rossera) and their potential for use at 15% and 25% in reformulating gluten-free baked snacks and fresh pasta. Chestnut varieties differ in protein and starch content (Balestrera > Rossera), as well as in amylose, dietary fiber, and lipids (Balestrera < Rossera). Differences in starch and amylose content affected starch gelatinization (Balestrera < Rossera), pasting and retrogradation properties, and water absorption capacity at 90 °C (Balestrera > Rossera). No differences in water and oil absorption capacity and mixing properties were observed, neither in the protein profile nor in the nature of protein aggregates. Both varieties exhibited a good aptitude for producing gluten-free baked snacks and fresh pasta, even at enrichment levels of 25%. Overall, this study could provide valuable information for the development of gluten-free products using sustainable, underutilized crops.

Enhancing grape preservation: The synergistic effect of curry leaf essential oil in buckwheat starch-chitosan composite coatings

A novel edible composite coating composed of buckwheat starch (BS) and chitosan (CH) with varying levels of curry leaf essential oil (CLEO) was synthesized in the present study. Initially, starch was extracted from buckwheat groats, and its proximate analysis revealed a high amylose content (21.91 ± 0.32%), which makes it an excellent base material for coating formation. The composite coatings were created by blending BS and CH with CLEO in different concentrations. The coatings underwent a comprehensive evaluation, including physico-chemical, functional, thermal analyses, and microstructural characterization. Cytotoxicity tests on human cell lines (Caco-2) confirmed that the coatings were non-toxic. Among the various formulations, the coating with 2.0% CLEO (referred to as F5) exhibited the highest antimicrobial activity, maximum antioxidant properties, and the lowest water solubility. Following this, the coatings were applied to green grapes (Vitis vinifera) via dip coating technique. The performance of coatings was assessed by storing the grapes under room temperature (25 ± 1 °C) and refrigeration conditions (4 ± 1 °C). From visual appearance and physio-chemical tests, it was concluded that the F5 coating was potentially active in extending the shelf life of grapes to 12 days at room temperature and to 20 days under refrigeration storage. Overall, the BS-CH-CLEO composite coating emerges as a refined and eco-conscious bioactive packaging solution, elegantly extending the shelf life of grapes while providing both sustainability and cost-efficiency.

The role of amylose content on the structure and rheological properties of pea protein-starch systems during pressurized hydrothermal processing

Legume proteins are often subjected to hydrothermal cooking in starch containing formulations. In this work we studied the formation of structure in mixed gels containing pea protein isolate (PPI) and three maize starch types (waxy, normal-amylose and high-amylose), distinct for their amylose content (0, 26 and 56%) and swelling properties. The starch, PPI and mixed hydrogels were processed at high moisture and high temperature, and the changes in apparent viscosity were followed in situ. The amylose content in starch granules was a key parameter determining micro-structure, water partitioning and mechanical properties of the mixed gels. PPI addition to high-amylose starch (HAMS) resulted in a delay of the onset of structure formation, measured by a build-up of viscosity, and reduced gelatinization. After heating, swollen and distorted granules were present, dispersed in a protein-dominated network. In this mixed gel, along with the greater resistance to swelling during gelatinization, there was a lower extent of retrogradation, less water migration, which also reduced the hardness increase during storage, compared to the other mixtures. In the gels containing waxy and normal-amylose starch, the microstructure denoted a starch-dominated network, with protein particles segregated in the interstitial spaces of the swollen gelatinized starch. The results well describe the dynamics of interactions occurring between these biopolymers, and are an important step towards understanding the importance of their interactions during hydrothermal cooking, highlighting the importance of phase formation during swelling.

Unveiling the synergistic effect of octenyl succinic anhydride and pulsed electric field on starch nanoparticles

In this study, guinea starch nanoparticles (GSNP) were prepared by nanoprecipitation technique and modified with octenyl succinic anhydride (3 %) and pulsed electric field (1.5, 3.0, and 4.5 kV/cm). The effect of dual modification on the physicochemical, structural, morphological, thermo-pasting, and rheological properties of GSNP was investigated. The dual modification successfully incorporated octenyl groups into GSNP, as confirmed by 1H nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. The degree of substitution increased from 0.0254 to 0.0347, with particle size ranging from 241.30 to 292.50 nm and zeta potential of −23.11 to −29.98 mV. TEM micrographs revealed that all SNP samples had self-aggregated granules with a mean size below 120 nm, and XRD confirmed a V-type crystalline structure. The amylose content and water absorption capacity decreased from 34.02 % to 24.63 % and from 2.45 to 1.91 g/g, respectively, while the oil absorption capacity and relative crystallinity increased from 3.42 to 4.01 g/g and from 17.82 % to 34.76 %, with modification. The gelatinization and degradation temperature of modified samples were higher while pasting properties exhibited variation with modification. The rheological properties of modified SNP samples exhibited more pronounced shear thinning, attributed to their weaker gel structure and fluid-like gel network. Overall, results suggested that modified GSNPs have potential for stabilizing Pickering emulsion and delivery of carrier materials for active functional substances.

Mechanism of maltogenic α-amylase modification on barley granular starches spanning the full range of amylose

Amylopectin (AP)-only (APBS), normal (NBS), and amylose (AM) only (AOBS) barley starches were selected here to investigate catalysis pattern of maltogenic α-amylase (MA) on hydrolyzing AP and AM granular starches. MA shortened starch side chains with degree of polymerization (DP) 11–30. MA-treated APBS exhibited porous granular structures and dramatically increased degree of branching (DB, 17–20 %), and reduced ordered degrees, suggesting high hydrolysis and transglycosylation activities of MA. MA-treated NBS showed less pronounced porous structures and slightly increased DB (2–4 %), indicating high hydrolysis but low transglycosylation activities. AOBS displayed minimal changes in DB (0.2–0.3 %) and starch structures, implying low hydrolysis and transglycosylation activities. Therefore, MA preferred to attack the AP molecules with abundant glucan substrates with DP 11–30, while AM restricted MA activity likely by creating ineffective binding sites and undergoing rapid reorganization. These findings deepened the understanding of the mechanisms of MA in modifying granular starches with varying AM content.

Single-helix inclusion formation of V-type starch-lutein: Investigation of structural, physicochemical, and in vitro release

Lutein is a natural plant pigment with a variety of biological functions. However, its low stability and bioavailability limits its use in the food industry. The ethanol-alkaline (EA) method was utilized to manufacture V-type starch to examine its impact on the stability and release properties of the V-type starch-lutein composite system. The EA treatment increased the amylose content of natural starch and transformed its structure from a typical B-type structure to a more open V-type structure. The results showed that lutein could be efficiently loaded into V-type starch, and fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) revealed that hydrogen bonding interaction, in conjunction with helical cavities rather than surface adsorption, was responsible for the lutein loading by V-type starch. The designed loading system enhanced lutein's photothermal stability, showing a two-fold increase compared to free lutein. V-type starch-lutein systems exhibited protection in gastric fluid and demonstrated sustained release post intestinal digestion. The findings had useful ramifications for the development of efficient delivery strategies for the encapsulation of lipophilic actives.

Effects of germination and gamma irradiation on physico-chemical and cooking qualities of pigmented red rice landrace: Ahu

The rice quality is influenced by various post-harvest treatments, including germination and gamma irradiation. The study investigates the combined effects of germination and gamma irradiation on the physico-chemical and cooking qualities of Ahu, a red rice landrace. The samples were subjected to germination for 0, 24, 48 and 72 hours and subsequently irradiated with gamma rays at doses of 0, 1, 2, 5 and 10 kGy. Post-treatment, samples were analyzed for proximate and mineral composition. Cooking quality parameters including cooking time, water absorption, and texture were also assessed. At a radiation dose of 2 kGy, both protein and carbohydrate content increased; however, they declined at higher doses. The ash content depicted a reduction with increased doses of radiation. Micronutrient composition remained largely unaffected by the irradiation process. Gamma irradiation also influenced cooking quality: water uptake ratio increased, while the optimum cooking time decreased at higher doses. Additionally, an upsurge of amylose content was demonstrated with increasing radiation levels, resulting in softer cooked rice. Thus, it can be attributed that dual processing of rice can effectively modify starch properties, rendering it a viable method for enhancing the textural and functional qualities.

Structural characterization and functional properties of resistant dextrins prepared from different starch sources.

The molecular structures of different starch sources differ, and the structure of the prepared resistant dextrin is affected. Seven types of starches (corn, wheat, pea, mung bean, tapioca, sweet potato, and potato) were used to prepare resistant dextrins under identical conditions. The physicochemical properties, molecular structure, micromorphology, glucose dialysis retardation index (GDRI), and cholesterol-binding capacity of different starch-resistant dextrins were analyzed and compared. The results revealed that the starch source exerted a greater effect on the structure of the resistant dextrins, and this was primarily attributed to the difference in the content of amylose and amylopectin. Both high amylose and high amylopectin may be the sources of highly resistant dextrins. The microscopic morphology of resistant dextrins were fragmentary, and the original form of starches was completely lost. Additionally, pea resistant dextrin exhibited higher GDRI values and stronger cholesterol-binding capacity compared to other samples.

Structural, molecular, and physicochemical properties of starch in high-amylose durum wheat lines

There is growing interest in the development of high-amylose cereals such as wheat due to their functional properties and nutritional value in foods. The increase in amylose content is associated with significant changes in the physicochemical, molecular, and structural characteristics of wheat starch which could affect its processing quality. The present study aimed to analyze the physicochemical, molecular, and structural characteristics of high-amylose starch from three durum wheat near isogenic lines (NILs), each obtained using three different recurrent parents. Morphology, granule size distribution, pasting and thermal properties, X-ray diffraction, and structural features were determined. The NILs showed the highest amylose content (65.3 and 69.8%), granules with an elongated shape, size between the wild-type and the mutant, restricted swelling in the pasting profile, the highest average and final gelatinization temperature, and B-polymorphism. The starches from the NILs showed the highest molar mass of amylopectin (AP) (7.0–7.6 × 107 Da) and the lowest amylose (AM) (1.1–1.8 × 106 Da), an issue associated with the biosynthesis of both components. The study on the debranched sample by high-performance size-exclusion chromatography showed that the high-amylose starch had the highest content of long B2 and B3 chains of AP (23.9–26.6%), which was corroborated with the high-performance anion-exchange chromatography analysis where the chains with degree of polymerization >37 had the highest content (18.3–19.1%). The PC1 is highly associated with the MwAM and the AM fraction in the debranched starch analyzed by HPSEC. Characterizing high-amylose durum wheat starch provides information to determine the structure-function relationship and design strategies to produce crosses with structural characteristics of AM and AP for specific applications.

Comparison of Structure and Physicochemical Properties of Starches from Hybrid Foxtail Millets and Their Parental Lines

The structure and physicochemical properties of starch were important factors to determine the quality of foxtail millet. While hybrid foxtail millet has made greater progress in yield, it has made slower progress in quality than conventional foxtail millet with a more complex genetic base, which was jointly influenced by the parents. However, there were no reports on the comparison of the starch structure and physicochemical properties of hybrid foxtail millets and their parents. In this study, the amylose content, morphology structure, granule size distribution, X-ray diffraction, short-range ordered structure, pasting properties, and thermal characteristics of starches derived from Changzagu 466 (466), Changzagu 333 (333), Changzagu 2922 (2922) and their parent materials were analyzed. The results showed that compared with male parents, the starches from three hybrid foxtail millets and their female parents had larger average particle size, d(0.1), d(0.5), and gelatinization enthalpy (ΔH), while the amylose content values of three hybrid foxtail millets were 26.0%, 28.8%, and 28.9%, which were between the parents (25.8~27.1%, 25.4~28.8%, and 23.6~29.5%), with conclusion temperature (Tc) being higher than the parents and having a lower breakdown viscosity. The peak viscosity of Changzagu 466 (466) and Changzagu 2922 (2922) was 5235.5 cP and 5190.8 cP, respectively, lower than that of their parents (5321.0~6006.0 cP and 5257.0~5580.7 cP), while the peak viscosity of Changzagu 333 (333) was 5473.8 cP, falling between the parental values (5337.5~5639.5 cP). The cluster analysis results showed that the starch structure and physicochemical properties of hybrid foxtail millet were significantly different from those of female parents, which were mainly influenced by male parents. The findings of this study will establish a theoretical foundation for the enhancement and innovation of high-quality foxtail millet germplasm resources, as well as the development of high-quality hybrid foxtail millet combinations.