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1.
Carbohydr Polym ; 339: 122264, 2024 Sep 01.
Article in English | MEDLINE | ID: mdl-38823928

ABSTRACT

Normal rice starch consists of amylopectin and amylose, whose relative amounts and chain-length distributions (CLDs) are major determinants of the digestibility and rheology of cooked rice, and are related to metabolic health and consumer preference. Here, the mechanism of how molecular structural features of pure amylopectin (waxy) starches affect starch properties was explored. Following debranching, chain-length distributions of seven waxy varieties were measured using size-exclusion chromatography, and parameterized using biosynthesis-based models, which involve breaking up the chain-length distribution into contributions from five enzyme sets covering overlapping ranges of chain length; structure-property correlations involving the fifth set were found to be statistically significant. Digestibility was measured in vitro, and parameters for the slower and longer digestion phase quantified using non-linear least-squares fitting. The coefficient for the significant correlation involving amylopectin fine structure for the fifth set was -0.903, while the amounts of amylopectin short and long chains were found to dominate breakdown viscosity (correlation coefficients 0.801 and - 0.911, respectively). This provides a methodology for finding or developing healthier starch in terms of lower digestion rate, while also having acceptable palatability. As rice breeders can to some extent control CLDs, this can help the development of waxy rices with improved properties.


Subject(s)
Amylopectin , Amylose , Oryza , Oryza/chemistry , Amylopectin/chemistry , Viscosity , Amylose/chemistry , Amylose/analysis , Starch/chemistry , Digestion , Rheology
2.
Nat Commun ; 15(1): 4493, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38802342

ABSTRACT

Abscisic acid (ABA) plays a crucial role in promoting plant stress resistance and seed dormancy. However, how ABA regulates rice quality remains unclear. This study identifies a key transcription factor SLR1-like2 (SLRL2), which mediates the ABA-regulated amylose content (AC) of rice. Mechanistically, SLRL2 interacts with NF-YB1 to co-regulate Wx, a determinant of AC and rice quality. In contrast to SLR1, SLRL2 is ABA inducible but insensitive to GA. In addition, SLRL2 exhibits DNA-binding activity and directly regulates the expression of Wx, bHLH144 and MFT2. SLRL2 competes with NF-YC12 for interaction with NF-YB1. NF-YB1 also directly represses SLRL2 transcription. Genetic validation supports that SLRL2 functions downstream of NF-YB1 and bHLH144 in regulating rice AC. Thus, an NF-YB1-SLRL2-bHLH144 regulatory module is successfully revealed. Furthermore, SLRL2 regulates rice dormancy by modulating the expression of MFT2. In conclusion, this study revealed an ABA-responsive regulatory cascade that functions in both rice quality and seed dormancy.


Subject(s)
Abscisic Acid , Gene Expression Regulation, Plant , Oryza , Plant Dormancy , Plant Proteins , Oryza/genetics , Oryza/metabolism , Abscisic Acid/metabolism , Plant Proteins/metabolism , Plant Proteins/genetics , Plant Dormancy/genetics , Transcription Factors/metabolism , Transcription Factors/genetics , CCAAT-Binding Factor/metabolism , CCAAT-Binding Factor/genetics , Seeds/metabolism , Seeds/growth & development , Basic Helix-Loop-Helix Transcription Factors/metabolism , Basic Helix-Loop-Helix Transcription Factors/genetics , Amylose/metabolism , Edible Grain/metabolism , Edible Grain/genetics , Plants, Genetically Modified
3.
Carbohydr Polym ; 337: 122190, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38710564

ABSTRACT

Starch structure is often characterized by the chain-length distribution (CLD) of the linear molecules formed by breaking each branch-point. More information can be obtained by expanding into a second dimension: in the present case, the total undebranched-molecule size. This enables answers to questions unobtainable by considering only one variable. The questions considered here are: (i) are the events independent which control total size and CLD, and (ii) do ultra-long amylopectin (AP) chains exist (these chains cannot be distinguished from amylose chains using simple size separation). This was applied here to characterize the structures of one normal (RS01) wheat and two high-amylose (AM) mutant wheats (an SBEIIa knockout and an SBEIIa and SBEIIb knockout). Absolute ethanol was used to precipitate collected fractions, then size-exclusion chromatography for total molecular size and for the size of branches. The SBEIIa and SBEIIb mutations significantly increased AM and IC contents and chain length. The 2D plots indicated the presence of small but significant amounts of long-chain amylopectin, and the asymmetry of these plots shows that the corresponding mechanisms share some causal effects. These results could be used to develop plants producing improved starches, because different ranges of the chain-length distribution contribute independently to functional properties.


Subject(s)
Amylopectin , Amylose , Starch Synthase , Triticum , Triticum/metabolism , Triticum/chemistry , Triticum/genetics , Amylopectin/chemistry , Amylopectin/biosynthesis , Amylose/chemistry , Amylose/biosynthesis , Starch Synthase/genetics , Starch Synthase/metabolism , Starch Synthase/chemistry , Starch/chemistry , Starch/biosynthesis , Starch/metabolism , Mutation , Plant Proteins/chemistry , Plant Proteins/genetics , Plant Proteins/metabolism
4.
Brief Funct Genomics ; 23(3): 193-213, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38751352

ABSTRACT

Starch is a significant ingredient of the seed endosperm with commercial importance in food and industry. Crop varieties with glutinous (waxy) grain characteristics, i.e. starch with high amylopectin and low amylose, hold longstanding cultural importance in some world regions and unique properties for industrial manufacture. The waxy character in many crop species is regulated by a single gene known as GBSSI (or waxy), which encodes the enzyme Granule Bound Starch Synthase1 with null or reduced activity. Several allelic variants of the waxy gene that contribute to varying levels of amylose content have been reported in different crop plants. Phylogenetic analysis of protein sequences and the genomic DNA encoding GBSSI of major cereals and recently sequenced millets and pseudo-cereals have shown that GBSSI orthologs form distinct clusters, each representing a separate crop lineage. With the rapidly increasing demand for waxy starch in food and non-food applications, conventional crop breeding techniques and modern crop improvement technologies such as gene silencing and genome editing have been deployed to develop new waxy crop cultivars. The advances in research on waxy alleles across different crops have unveiled new possibilities for modifying the synthesis of amylose and amylopectin starch, leading to the potential creation of customized crops in the future. This article presents molecular lines of evidence on the emergence of waxy genes in various crops, including their genesis and evolution, molecular structure, comparative analysis and breeding innovations.


Subject(s)
Crops, Agricultural , Starch Synthase , Crops, Agricultural/genetics , Starch Synthase/genetics , Starch Synthase/metabolism , Genotype , Plant Proteins/genetics , Plant Proteins/metabolism , Amylose/metabolism , Amylose/genetics , Amylopectin/metabolism , Amylopectin/genetics , Phylogeny , Starch/metabolism , Starch/genetics , Starch/biosynthesis
5.
Chirality ; 36(5): e23679, 2024 May.
Article in English | MEDLINE | ID: mdl-38752268

ABSTRACT

Each year, new psychoactive substances appear on the global drug market leading to constant changes. Most of these compounds with stimulating effect possess a chiral center, thus leading to two enantiomers with presumably different pharmacological properties. Among them, synthetic cathinones, often misleadingly traded as "bath salts," play an important role. There is little knowledge about the distinct effect of the enantiomers. The aim of this study was to test a commercially available Lux® i-Amylose-3 column by HPLC-UV for enantiorecognition of cathinone derivatives. Overall, 80 compounds were tested in normal phase mode, where 75 substances were separated under initial conditions. After method optimization, at least partial separation was achieved for the remaining compounds. The same set of substances was measured in polar-organic mode, where 63 analytes were resolved into their enantiomers under initial conditions with very short retention times. Both modes showed complementary results for the individual compounds. Furthermore, the tested methods proved to be suitable for differentiation of positional isomers, which can be useful for drug checking programs. All measurements were carried out under isocratic conditions, and intraday and interday repeatability tests were performed.


Subject(s)
Alkaloids , Stereoisomerism , Chromatography, High Pressure Liquid/methods , Alkaloids/chemistry , Alkaloids/isolation & purification , Amylose/chemistry , Amylose/analogs & derivatives , Pyrrolidines
6.
Int J Biol Macromol ; 268(Pt 2): 131996, 2024 May.
Article in English | MEDLINE | ID: mdl-38697417

ABSTRACT

This research investigated the effect of lecithin on the complexation of lauric acid with maize starch, potato starch, waxy maize starch, and high amylose maize starch. Rapid visco analysis showed that lecithin altered the setback pattern of potato starch-lauric acid and maize starch-lauric acid mixtures but not waxy maize starch-lauric acid. Further investigation, including differential scanning calorimetry, complex index, and X-ray diffraction, showed that lecithin enhanced the complexation of maize starch, potato starch, and high amylose maize starch with lauric acid. Fourier transform infrared and Raman spectroscopy revealed increasingly ordered structures formed in maize starch-lauric acid-lecithin, potato starch-lauric acid-lecithin, and high amylose maize starch-lauric acid-lecithin systems compared to corresponding binary systems. These highly ordered complexes of maize starch, potato starch, and high amylose maize starch also demonstrated greater resistance to in vitro enzymatic hydrolysis. Waxy maize starch complexation however remained unaffected by lecithin. The results of this study show that lecithin impacts complexation between fatty acids and native starches containing amylose, with the starch source being critical. Lecithin minimally impacted the complexation of low amylose starch and fatty acids.


Subject(s)
Amylose , Lauric Acids , Lecithins , Starch , Zea mays , Lauric Acids/chemistry , Lecithins/chemistry , Starch/chemistry , Amylose/chemistry , Zea mays/chemistry , Solanum tuberosum/chemistry , Hydrolysis , X-Ray Diffraction , Spectroscopy, Fourier Transform Infrared , Calorimetry, Differential Scanning
7.
Food Res Int ; 183: 114186, 2024 May.
Article in English | MEDLINE | ID: mdl-38760125

ABSTRACT

The rise of pre-diabetes at the global level has created a significant interest in developing low glycaemic index food products. The pearl millet is a cheaper source of starch and its germ contains significant amount of protein and fat. The complexing of pearl millet starch and germ by dry heat treatment (PMSGH) resulted an increase in the resistant starch content upto 45.09 % due to formation of amylose-glutelin-linoleic acid complex. The resulting pearl millet starch germ complex was incorporated into wheat bread at 20, 25, and 30 %. The PMSGH incorporated into bread at 30 % reduced the glycaemic index to 52.31. The PMSGH incorporated bread had significantly (p < 0.05)increased in the hardness with a reduction in springiness and cohesiveness. The structural attributes of the 30 % PMSGH incorporated bread revealed a significant (p < 0.05)increase in 1040/1020 cm-1 ratio and relative crystallinity. The consumption of functional bread incorporated with pearl millet starch germ complex reduced blood glucose levels and in vivo glycaemic index in healthy and pre-diabetic participants when compared to white bread. Hence, the study showed that the incorporation of pearl millet starch-germ complex into food products could be a potential new and healthier approach for improving dietary options in pre-diabetes care.


Subject(s)
Blood Glucose , Bread , Glycemic Index , Pennisetum , Prediabetic State , Starch , Humans , Bread/analysis , Pennisetum/chemistry , Starch/chemistry , Male , Adult , Female , Nutritive Value , Single-Blind Method , Young Adult , Middle Aged , Amylose/chemistry
8.
Food Res Int ; 183: 114226, 2024 May.
Article in English | MEDLINE | ID: mdl-38760145

ABSTRACT

Highland barley (HB) is an intriguing plateau cereal crop with high nutrition and health benefits. However, abundant dietary fiber and deficient gluten pose challenges to the processing and taste of whole HB products. Extrusion technology has been proved to be effective in overcoming these hurdles, but the association between the structure and physicochemical properties during extrusion remains inadequately unexplored. Therefore, this study aims to comprehensively understand the impact of extrusion conditions on the physicochemical properties of HB flour (HBF) and the multi-scale structure of starch. Results indicated that the nutritional value of HBF were significantly increased (soluble dietary fiber and ß-glucan increased by 24.05%, 19.85% respectively) after extrusion. Typical underlying mechanisms based on starch structure were established. High temperature facilitated starch gelatinization, resulting in double helices unwinding, amylose leaching, and starch-lipid complexes forming. These alterations enhanced the water absorption capacity, cold thickening ability, and peak viscosity of HBF. More V-type complexes impeded amylose rearrangement, thus enhancing resistance to retrogradation and thermal stability. Extrusion at high temperature and moisture exhibited similarities to hydrothermal treatment, partly promoting amylose rearrangement and enhancing HBF peak viscosity. Conversely, under low temperature and high moisture, well-swelled starch granules were easily broken into shorter branch-chains by higher shear force, which enhanced the instant solubility and retrogradation resistance of HBF as well as reduced its pasting viscosity and the capacity to form gel networks. Importantly, starch degradation products during this condition were experimentally confirmed from various aspects. This study provided some reference for profiting from extrusion for further development of HB functional food and "clean label" food additives.


Subject(s)
Amylose , Flour , Food Handling , Hordeum , Starch , Hordeum/chemistry , Starch/chemistry , Flour/analysis , Viscosity , Amylose/chemistry , Food Handling/methods , Nutritive Value , Dietary Fiber/analysis , Solubility , beta-Glucans/chemistry , Chemical Phenomena , Hot Temperature
9.
Carbohydr Polym ; 338: 122213, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38763715

ABSTRACT

The present research studies the impact of apparent amylose content (AAC) on the quality of fortified rice kernels (FRK), a health food designed to combat iron deficiency anemia by fortifying with iron, folic acid, and vitamin B12. Five FRK formulations with varying AAC (0.46-23.89 %) were prepared, and AAC influence on the extruder-system parameter and physicochemical, cooking, and textural properties of FRK was investigated. The torque, die-pressure, length, redness, and cooking time increased with an increase in AAC and were in the range of 12.55-22.81 Nm, 58.31-88.96 bar, 4.58-5.09 mm, 0.35-1.15, and 6.1-11.2 min, respectively. The other parameters, such as the breadth, whiteness index, and cooking loss decreased with an increase in AAC. Except for cohesiveness, all other textural properties of cooked FRK increased with an increase in AAC. These correlations of the FRK properties with AAC were confirmed through multivariate analysis. SEM, XRD, FTIR, and rheology supported the observed AAC trends in FRK properties. SEM showed a reduction in pores and cracks with an increase in AAC. The XRD and FTIR showed an increase in crystallinity with an increase in AAC due to better gelatinization leading to rapid retrogradation. This leads to better physical, cooking, and textural properties of FRK.


Subject(s)
Amylose , Cooking , Oryza , Oryza/chemistry , Amylose/analysis , Amylose/chemistry , Food, Fortified/analysis , Rheology
10.
Carbohydr Polym ; 338: 122208, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38763729

ABSTRACT

This study examines the impact and influence of amylose on the starch esterification reaction through partial extraction of amylose. Citric acid was added for the esterification reaction, and then the esterified starches' multiscale structure, physicochemical, and functional properties were evaluated. As the extraction time of amylose increased, the amylose content in the starch decreased. Higher concentrations of citric acid will lead to samples with a higher degree of substitution, with DS rising from 0.203 % (0 h) to 0.231 % (3.5 h) at CA3 treatment. While removing amylose had minimal effects on the crystal structure of starch granules, it did decrease the ratio of A and B1 chains and the molecular weight of amylose. Acid hydrolysis exacerbated these changes upon the addition of citric acid. Furthermore, removing amylose followed by citrate esterification resulted in lower pasting viscosity, enthalpy of gelatinization (from 13.37 J to 2.83 J), and degree of short-range ordering. Also, digestion shows a decrease caused by the increasing content of slow-digesting starch. The presence of amylose in starch granules does affect the formation of starch esters, and removing it before esterification modification may improve production efficiency and reduce costs to some extent.


Subject(s)
Amylose , Citric Acid , Solanum tuberosum , Starch , Amylose/chemistry , Esterification , Citric Acid/chemistry , Solanum tuberosum/chemistry , Starch/chemistry , Viscosity , Hydrolysis , Molecular Weight
11.
Food Res Int ; 186: 114381, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38729735

ABSTRACT

Lipid has crucial applications in improving the quality of starchy products during heat processing. Herein, the influence of lipid modification and thermal treatment on the physicochemical properties and starch digestibility of cooked rice prepared with varied addition manipulations was investigated. Rice bran oil (RO) and medium chain triglyceride oil (MO) manipulations were performed either before (BC) or after cooking (AC). GC-MS was applied to determine the fatty acid profiles. Nutritional quality was analyzed by quantifying total phenolics, atherogenic, and thrombogenic indices. All complexes exhibited higher surface firmness, a soft core, and less adhesive. FTIR spectrum demonstrated that the guest component affected some of the dense structural attributes of V-amylose. The kinetic constant was in the range between 0.47 and 0.86 min-1 wherein before mode presented a higher value. The lowest glucose release was observed in the RO_BC sample, whereas the highest complexing index was observed in the RO_AC sample, indicating that the dense molecular configuration of complexes that could resist enzymatic digestion was more critical than the quantity of complex formation. Despite the damage caused by mass and heat transfer, physical barrier, intact granule forms, and strengthened dense structure were the central contributors affecting the digestion characteristics of lipid-starch complexes.


Subject(s)
Cooking , Digestion , Oryza , Rice Bran Oil , Starch , Triglycerides , Oryza/chemistry , Starch/chemistry , Rice Bran Oil/chemistry , Triglycerides/chemistry , Hot Temperature , Fatty Acids/analysis , Fatty Acids/chemistry , Plant Oils/chemistry , Spectroscopy, Fourier Transform Infrared , Nutritive Value , Amylose/chemistry , Gas Chromatography-Mass Spectrometry
12.
Int J Biol Macromol ; 269(Pt 2): 132159, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38719018

ABSTRACT

In recent years, the focus has shifted towards carbohydrate-based hydrogels and their eco-friendly preparation methods. This study involved an investigation into the treatment of wheat starch using dielectric barrier discharge (DBD) plasma technology over varying time gradients (0, 2, 5, 10, 15, and 20 min). The objective was to systematically examine the impact of different treatment durations on the physicochemical properties of wheat starch and the suitability of its gels for 3D printing. Morphology of wheat starch remained intact after DBD treatment. However, it led to a reduction in the amylose content, molecular weight, and crystallinity. This subsequently resulted in a decrease in the pasting temperature and viscosity. Moreover, the gels of the DBD-treated starch exhibited superior 3D printing performance. After a 2-min DBD treatment, the 3D printed samples of the wheat starch gel showed no significant improvements, as broken bars were evident on the surface of the 3D printed graphic, whereas DBD-20 showed better printing accuracy and surface structure, compared to the original starch without slumping. These results suggested that DBD technology holds potential for developing new starch-based gels with impressive 3D printing properties.


Subject(s)
Printing, Three-Dimensional , Starch , Triticum , Triticum/chemistry , Starch/chemistry , Amylose/chemistry , Viscosity , Plasma Gases/chemistry , Molecular Weight , Chemical Phenomena , Temperature
13.
Int J Biol Macromol ; 269(Pt 2): 132183, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38723826

ABSTRACT

The current research in the food industry regarding enzymatic modification to enhance the freeze-thaw (FT) stability of starch is limited. The present study aimed to investigate the FT stability of normal corn starch (NCS) modified using 1,4-α-glucan branching enzyme (GBE) derived from Geobacillus thermoglucosidans STB02. Comprehensive analyses, including syneresis, scanning electron microscopy, and low-field nuclear magnetic resonance, collectively demonstrated the enhanced FT stability of GBE-modified corn starch (GT-NCS-30) in comparison to its native form. Its syneresis was 66.4 % lower than that of NCS after three FT cycles. Notably, GBE treatment induced changes in the pasting properties and thermal resistance of corn starch, while simultaneously enhancing the mechanical strength of the starch gel. Moreover, X-ray diffractograms and microstructural assessments of freeze-thawed gels indicated that GBE treatment effectively hindered the association of corn starch molecules, particularly amylose retrogradation. The enhanced FT stability of GBE-modified starch can be attributed to alterations in the starch structure induced by GBE. This investigation establishes a foundation for further exploration into the influence of GBE treatment on the FT stability of starch and provides a theoretical basis for further research in this area.


Subject(s)
1,4-alpha-Glucan Branching Enzyme , Freezing , Gels , Starch , Zea mays , Starch/chemistry , 1,4-alpha-Glucan Branching Enzyme/chemistry , 1,4-alpha-Glucan Branching Enzyme/metabolism , Zea mays/chemistry , Gels/chemistry , Geobacillus/enzymology , Amylose/chemistry
14.
Int J Biol Macromol ; 267(Pt 1): 131488, 2024 May.
Article in English | MEDLINE | ID: mdl-38615862

ABSTRACT

This study aimed to reveal the underlying mechanisms of the differences in viscoelasticity and digestibility between mung bean starch (MBS) and proso millet starch (PMS) from the viewpoint of starch fine molecular structure. The contents of amylopectin B2 chains (14.94-15.09 %), amylopectin B3 chains (14.48-15.07 %) and amylose long chains (183.55-198.84) in MBS were significantly higher than PMS (10.45-10.76 %, 12.48-14.07 % and 70.59-88.03, respectively). MBS with higher amylose content (AC, 28.45-31.80 %) not only exhibited a lower weight-average molar mass (91,750.65-128,120.44 kDa) and R1047/1022 (1.1520-1.1904), but also was significantly lower than PMS in relative crystallinity (15.22-23.18 %, p < 0.05). MBS displayed a higher storage modulus (G') and loss modulus (G'') than PMS. Although only MBS-1 showed two distinct and discontinuous phases, MBS exhibited a higher resistant starch (RS) content than PMS (31.63-39.23 %), with MBS-3 having the highest RS content (56.15 %). Correlation analysis suggested that the amylopectin chain length distributions and AC played an important role in affecting the crystal structure, viscoelastic properties and in vitro starch digestibility of MBS and PMS. These results will provide a theoretical and scientific basis for the development of starch science and industrial production of low glycemic index starchy food.


Subject(s)
Amylopectin , Amylose , Starch , Vigna , Amylose/chemistry , Amylose/analysis , Amylopectin/chemistry , Viscosity , Vigna/chemistry , Starch/chemistry , Starch/metabolism , Elasticity , Digestion , Molecular Weight
15.
J Nutr Sci Vitaminol (Tokyo) ; 70(2): 139-149, 2024.
Article in English | MEDLINE | ID: mdl-38684384

ABSTRACT

Since propionate exerts several physiological effects, maintenance of its normal colonic fermentation is essential. To investigate whether vitamin B12 (VB12) is essential for normal propionate fermentation by colonic bacteria, via the succinate pathway, we examined if high-amylose cornstarch (HACS) feeding activated such a pathway, if high HACS feeding impaired propionate fermentation, and if oral VB12 supplementation normalized propionate fermentation. Male rats were given control, 20% HACS or 3% fucose diets (Expt. 1); a VB12-free control diet or one supplemented with 5-30% HACS (Expt. 2); and the 20% HACS diet supplemented with 0.025-25 mg/kg of VB12 (Expt. 3), for 14 d. HACS feeding significantly increased cecal succinate concentration, activating the succinate pathway (Expt. 1). Cecal cobalamin concentration in 20% and 30% HACS groups was about 75% of that in the control group (Expt. 2). Cecal succinate and propionate concentrations significantly increased and decreased in 30% HACS groups, respectively, compared with the control group. Although HACS group supplemented with 0.025 mg/kg of VB12 had a low concentration of cecal propionate, adding high amounts of VB12 to HACS diets provided sufficient amounts of VB12 to rat ceca and increased cecal propionate concentration (Expt. 3). Compared with the non-HACS group, the relative abundance of Akkermansia muciniphila, but not Bacteroides/Phocaeicola, was lower in the HACS counterpart and showed improvement with increased VB12 doses. To summarize, feeding high HACS decreased and increased cecal VB12 and succinate concentrations, respectively. Furthermore, colonic delivery of sufficient amounts of VB12 to rats likely reduced accumulation of succinate and normalized propionate fermentation.


Subject(s)
Amylose , Cecum , Colon , Dietary Supplements , Fermentation , Propionates , Starch , Vitamin B 12 , Animals , Male , Propionates/metabolism , Cecum/microbiology , Cecum/metabolism , Vitamin B 12/administration & dosage , Vitamin B 12/pharmacology , Colon/metabolism , Colon/microbiology , Starch/metabolism , Starch/administration & dosage , Amylose/administration & dosage , Amylose/metabolism , Rats , Succinic Acid/metabolism , Diet , Rats, Wistar , Rats, Sprague-Dawley
16.
Plant Mol Biol ; 114(3): 50, 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38656412

ABSTRACT

Amylose biosynthesis is strictly associated with granule-bound starch synthase I (GBSSI) encoded by the Waxy gene. Mutagenesis of single bases in the Waxy gene, which induced by CRISPR/Cas9 genome editing, caused absence of intact GBSSI protein in grain of the edited line. The amylose and amylopectin contents of waxy mutants were zero and 31.73%, while those in the wild type were 33.50% and 39.00%, respectively. The absence of GBSSI protein led to increase in soluble sugar content to 37.30% compared with only 10.0% in the wild type. Sucrose and ß-glucan, were 39.16% and 35.40% higher in waxy mutants than in the wild type, respectively. Transcriptome analysis identified differences between the wild type and waxy mutants that could partly explain the reduction in amylose and amylopectin contents and the increase in soluble sugar, sucrose and ß-glucan contents. This waxy flour, which showed lower final viscosity and setback, and higher breakdown, could provide more option for food processing.


Subject(s)
Amylose , Gene Editing , Hordeum , Plant Proteins , Starch Synthase , Amylose/metabolism , Hordeum/genetics , Hordeum/metabolism , Gene Editing/methods , Starch Synthase/genetics , Starch Synthase/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , CRISPR-Cas Systems , Amylopectin/metabolism , Sucrose/metabolism , Sugars/metabolism , Gene Expression Regulation, Plant , Mutation , beta-Glucans/metabolism , Plants, Genetically Modified , Solubility
17.
Carbohydr Polym ; 335: 122086, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38616071

ABSTRACT

Recently, attention has been paid to cellulose nanofibers, such as 2,2,6,6-tetramethylpiperidine-1-oxyl-oxidized cellulose nanofibers (TOCN), as new bio-based materials. In addition, hydrophobized surface on TOCNs can be expected to provide new applications. Based on our previous finding that partially 2-deoxygenated (P2D)-amylose, which was synthesized by GP-catalyzed enzymatic copolymerization of D-glucal with α-d-glucose 1-phosphate (Glc-1-P) as comonomers, was hydrophobic, in this study, hydrophobization of surfaces on TOCNs was investigated by the GP-catalyzed enzymatic grafting of P2D-amylose chains on TOCNs. After maltooligosaccharide primers were modified on TOCNs, the GP-catalyzed enzymatic copolymerization of D-glucal with Glc-1-P was performed for grafting of P2D-amylose chains. 1H NMR spectroscopic analysis confirmed the production of P2D-amylose-grafted TOCNs with different 2-deoxyglucose/Glc unit ratios. The powder X-ray diffraction profiles of the products indicated that the entire crystalline structures were strongly affected by the unit ratios and chain lengths of the grafted polysaccharides. The SEM images observed differences in nanofiber diameter in the reaction solutions and surface morphology after film formation, due to grafting of P2D-amylose chains from TOCNs. The water contact angle measurement of a cast film prepared from the product indicated its hydrophobicity.


Subject(s)
Cellulose, Oxidized , Nanofibers , Cellulose , Amylose , Calcium Gluconate
18.
Carbohydr Polym ; 335: 122070, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38616092

ABSTRACT

Starches are hydrolyzed into monosaccharides by mucosal α-glucosidases in the human small intestine. However, there are few studies assessing the direct digestion of starch by these enzymes. The objective of this study was to investigate the changes in the structure and enzyme binding of starches during in vitro hydrolysis by mammalian mucosal enzymes. Waxy maize (WMS), normal maize (NMS), high-amylose maize (HAMS), waxy potato (WPS), and normal potato (NPS) starches were examined. The order of the digestion rate was different compared with other studies using a mixture of pancreatic α-amylase and amyloglucosidase. NPS was digested more than other starches. WPS was more digestible than WMS. Hydrolyzed starch from NPS, NMS, WPS, WMS, and HAMS after 24 h was 66.4, 64.2, 61.7, 58.7, and 46.2 %, respectively. Notably, a significant change in the morphology, reduced crystallinity, and a decrease in the melting enthalpy of the three starches (NPS, NMS, and WPS) after 24 h of hydrolysis were confirmed by microscopy, X-ray diffraction, and differential scanning calorimetry, respectively. The bound enzyme fraction of NPS, NMS, and WPS increased as hydrolysis progressed. In contrast, HAMS was most resistant to hydrolysis by mucosal α-glucosidases in terms of digestibility, changes in morphology, crystallinity, and thermal properties.


Subject(s)
Starch , alpha-Glucosidases , Humans , Animals , Hydrolysis , Amylose , Calorimetry, Differential Scanning , Waxes , Zea mays , Mammals
19.
Food Res Int ; 184: 114254, 2024 May.
Article in English | MEDLINE | ID: mdl-38609232

ABSTRACT

Polysaccharides have a significant impact on the physicochemical properties of starch, and the objective of this study was to examine the effect of incorporating soluble soybean polysaccharide (SSPS) on the gelatinization and retrogradation of corn starches (CS) with varying amylose content. In contrast to high-amylose corn starch (HACS), the degree of gelatinization of waxy corn starch (WCS) and normal corn starch (NCS) decreased with the addition of SSPS. The inclusion of SSPS resulted in reduced swelling power in all CS, and led to a decrease in gel hardness of the starches. The intermolecular forces between SSPS and CS were primarily hydrogen bonding, and a gel network structure was formed, thereby retarding the short-term and long-term retrogradation of CS. Scanning electron microscopy results revealed that the addition of SSPS in starches led to a loose network structure with larger poles and a reduced ordered structure after retrogradation, as observed from the cross-section of formed gels. These findings suggested that SSPS has great potential for applications in starchy foods, as it can effectively retard both gelatinization and retrogradation of starches.


Subject(s)
Amylose , Glycine max , Zea mays , Starch , Polysaccharides , Amylopectin
20.
Food Res Int ; 184: 114267, 2024 May.
Article in English | MEDLINE | ID: mdl-38609244

ABSTRACT

Hot extrusion is utilized for starch modification due to its high mechanical input and product output. Amylose recrystallization commences and primarily depends on intermolecular interactions after conventional extrusion. Hence, the design of a new component based on the existed extrusion system was aimed at facilitating molecular aggregation, potentially accelerating starch recrystallization. In this study, a nozzle sheet comprising 89 holes was integrated into the cooling die. The impact of the multihole nozzle on the structure and in vitro digestibility of extruded maize starches after retrogradation was examined at varying cooling die temperatures. The results showed that the nozzle-assembled extrusion system operated effectively without additional mechanical or yield losses. At 50 °C, the crystallinity of nozzle-produced starch was approximately 70 % higher than that of conventionally extruded starch, predominantly owing to the B-type allomorph of the amylose double helix. Recrystallized amylopectin was also found in these nozzle-produced starches, indicating that multihole nozzle-induced uniaxial elongational flow resulted in the rapid starch crystallization. The increased formation of recrystallized amylose led to improved molecular order in starch structures while reducing their digestibility. These findings revealed a new approach to improve starch crystallinity by incorporating a nozzle sheet in the extrusion process.


Subject(s)
Amylose , Zea mays , Temperature , Cold Temperature , Starch
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