Molecular order and functional properties of starches from three waxy wheat varieties grown in China

Incorporation of germinated lupin into corn-based extrudates: Focus on starch digestibility, matrix structure and physicochemical properties

The research aimed to assess the effects of incorporating germinated Lupinus angustifolius flour into corn extrudates for different periods (3, 5, and 7 days), focusing on starch digestibility, morphological structure, thermal, and pasting properties. Extrudate with germinated lupinus flour for 7 days (EG7) significantly increased the content of slowly digestible starch up to 10.56% (p < 0.05). Crystallinity increased up to 20% in extrudates with germinated flour compared to extrudates with ungerminated flour (EUG), observing changes at the molecular level by FTIR that impact the thermal and pasting properties. X-ray diffraction revealed angles of 2θ = 11.31, 16.60, 19.91, and 33.04 as a result of the germination and extrusion processes. Microstructural analysis indicated starch-protein interactions influencing changes in calorimetry, viscosity, X-ray diffraction, and digestibility. PCA allowed establishing that the addition of germinated flours significantly affected the properties and microstructural characteristics of extruded products, potentially affecting digestibility and nutritional quality.

Ultrasound and enzyme treatments on morphology, structures, and adsorption properties of cassava starch

Porous starch materials are environmentally friendly and renewable and exhibit high adsorption performances. Ultrasound and compound enzyme (α-amylase and glucoamylase) treatments were applied to prepare modified cassava starch. The granules, crystal morphology, crystal structure, and molecular structure of starch were investigated. The hydrolysis degree, solubility, swelling, and adsorption properties of cassava starch were analyzed. After the cassava starch was modified by ultrasound and enzyme treatments, the granule size of the starch decreased, and the surfaces were eroded to form pits, grooves and cavity structure. The starch spherulites weakened or even disappeared. The functional groups of starch did not change significantly, but the degree of crystal order decreased. The double-helix structure was reduced, and the crystal structure was composed of A + V-type crystals, with a decrease in crystallinity. The gelatinization temperature and thermal degradation temperatures enhanced. The enzymatic hydrolysis degree and solubility of the modified cassava starch increased. The swelling degree decreased, and oil adsorption, water adsorption improved. MB adsorption behavior of modified cassava starch closely followed a pseudo-second-order kinetics model and the Langmuir isotherm equation. These findings could help to understand the relationship between the structure and properties of modified starch, and guide its application in the field of adsorption.

Effect of ultrasound/CaCl2 co-treatment on the microstructure, gelatinization, and film-forming properties of high amylose corn starch

The effect of ultrasound/CaCl2 co-treatment on aggregation structure, thermal stability, rheological, and film properties of high amylose corn starch (HACS) was investigated. The scanning electron microscopy (SEM) images revealed the number of starch fragments and malformed starch granules increased after co-treatment. The differential scanning calorimetry (DSC) results showed the co-treated HACS got a lower gelatinization temperature (92.65 ± 0.495 °C) and enthalpy values (ΔH, 4.14 ± 0.192 J/g). The optical microscope images indicated that lesser Maltase crosses were observed in co-treated HACS. The results of X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) indicated ultrasound influenced the compactness of amorphous zone and CaCl2 damaged the crystalline region of HACS granules. Additionally, the rheology properties of HACS dispersion demonstrated the apparent viscosity of co-treated dispersion increased as the ultrasound time prolonged. The mechanical strength and structural compactness of HACS films were improved after ultrasound treatment. The mechanism of ultrasound/CaCl2 co-treatment improved the gelatinization and film-forming ability of HACS was that (i) ultrasound wave loosened the HACS granules shell, promoted the treatment of CaCl2 on HACS granules, and (ii) ultrasound wave improved the uniform distribution of HACS dispersion, increased the interaction between CaCl2 and starch chains during the process of film-forming.

Long-Chain Saturated Fatty Acids in Olive Diacylglycerol Stearin Enhances Resistant Starch Content of Candelilla Wax Oleogel Cookies

The purpose of this study was to substitute shortening with olive diacylglycerol oil/candelilla wax (OCW)-olive diacylglycerol stearin (ODS) oleogels and evaluate their impact on starch digestibility in cookies. The in vitro digestibility study confirmed that the OCW/ODS-based cookies exhibited a notable enhancement of 14.6% in slowly digestible starch (SDS) and an increase of 3.14% in resistant starch (RS) values when contrasted with shortening cookies. The XRD pattern indicated that the existence of ODS may improve the formation of complexes between lipids and amylose. The DSC analysis demonstrated that the incorporation of ODS led to a remarkable rise in enthalpy alteration, escalating from 0.90 to 437.70 J/g, suggesting an improved ability to resist gelatinization. The FTIR spectra suggested that the incorporation of ODS might strengthen interactions between the hydrogen bonds and form the short-range ordered structure in OCW/ODS-based cookies. Overall, these results indicated that incorporating OCW/ODS-based oleogels could serve as a feasible substitute for conventional shortening in cookies with decreased starch digestibility.

The lipid-amylose complexes enhance resistant starch content in candelilla wax-based oleogels cookies

The substitution of margarine with candelilla wax (CW)-based oleogel is currently a prominent focus of research in the bakery industry. However, the use of CW-based oleogel in cookies increased starch digestibility, potentially posing a risk to human health. Thus, the anti-enzymatic mechanism of lipid-amylose complexes was used to evaluate the influence of olive diacylglycerol stearin (ODS) on starch digestibility in CW-based oleogel cookies. The in vitro digestibility analysis demonstrated that the DCW/ODS-35 cookie exhibited a increase of 27.72 % in slowly digestible starch (SDS) and resistant starch (RS) contents, compared to cookie formulated with margarine. The in-vivo glycemic index analysis revealed that the DCW/ODS-35 cookie had a medium glycemic index of 68. XRD pattern suggested that the presence of ODS in oleogels facilitated the formation of lipid-amylose complexes. The DSC analysis revealed that the addition of ODS resulted in the gelatinization enthalpy of DCW-based cookies increased from 389.9 to 3314.9 J/g. The FTIR spectra indicated that the combination of ODS could promote a short-range ordered structure in DCW-based cookies. Overall, these findings demonstrated that the utilization of DCW-based oleogel presented a viable alternative to commercial margarine in the development of CW-based cookies with reduced starch digestibility.

Ozone modification of waxy rice starch nanocrystals: Effects on the multi-scale structural and surface properties

The rich active hydroxyl groups on starch nanocrystals (SNC) surface limits its dispersion and stability in the aqueous phase. To address this issue, ozone modification for 0 (SNC), 0.5 (SNC-1), 1 (SNC-2), 1.5 (SNC-3), and 2 h (SNC-4) as compared to conventionally chemical methods was applied to functionally modify the SNC. The impact of ozone treatment on the structural and surface characteristics of waxy rice starch nanocrystals. The findings revealed that longer ozone treatment durations favored the formation of carbonyl groups in starch molecules. Initially, ozone oxidized the hydroxyl group of the macromolecule. Once the carbonyl groups formed, the cross-linking reaction occurred among starch nanocrystals through condensation reactions, leading to the increasing molecular orderliness. X-ray photoelectron spectroscopy, X-ray diffraction and Small-angle X-ray scattering analyses of SNC-2 supported this finding with a reduced O/C ratio, and implied that surface oxidation did not alter the crystal type but rather enhanced molecular hydration in an aqueous system, leading to increased interfacial thickness and fractal dimension. Additionally, ozone oxidation improved surface properties such as charge and hydrophobicity. Oxidized SNC also exhibited altered gelatinization properties due to surface degradation. This study offers a promising strategy for enhancing SNC surface properties, crucial for food science applications.

The role of C18 fatty acids in improving the digestion and retrogradation properties of highland barley starch

In this study, five C18 fatty acids (FA) with different numbers of double bonds and configurations including stearic acid (SA), oleic acid (OA), elaidic acid (EA), linoleic acid (LA), and α-linolenic acid (ALA), were selected to prepare highland barely starch (HBS)-FA complexes to modulate digestibility and elaborate the underlying mechanism. The results showed that HBS-SA had the highest complex index (34.18 %), relative crystallinity (17.62 %) and single helix content (25.78 %). Furthermore, the HBS-C18 FA complexes were formed by EA (C18 FA with monounsaturated bonds) that had the highest R1047/1022 (1.0509) and lowest full width at half-maximum (FWHM, 20.85), suggesting good short-range ordered structure. Moreover, all C18 FAs could form two kinds of V-type complexes with HBS, which can be confirmed by the results of CLSM and DSC measurements, and all of them showed significantly lower digestibility. HBS-EA possessed the highest resistant starch content (20.17 %), while HBS-SA had the highest slowly digestible starch content (26.61 %). In addition, the inhibition of HBS retrogradation by fatty acid addition was further proven, where HBS-SA gel firmness (37.80 g) and aging enthalpy value were the lowest, indicating the most effective. Overall, compounding with fatty acids, especially SA, could be used as a novel way to make functional foods based on HBS.

Enhancement of resistant starch content in ethyl cellulose-based oleogels cakes with the incorporation of glycerol monostearate

The objective of this work was to completely replace margarine with peanut diacylglycerol oil/ethyl cellulose-glycerol monostearate oleogel (DEC/GMS) oleogel, and evaluate its effect on starch digestibility of cakes. The in vitro digestibility analysis demonstrated that the DEC/GMS-6 cake exhibited a 26.36% increase in slowly digestible starch (SDS) and resistant starch (RS) contents, compared to cakes formulated with margarine. The increased SDS and RS contents might mainly be due to the hydrophobic nature of OSA-wheat flour, which could promote the formation of lipid-amylose complexes with GMS and peanut diacylglycerol oil. XRD pattern suggested that the presence of GMS in DEC-based oleogels facilitated the formation of lipid-amylose complexes. The DSC analysis revealed that the addition of GMS resulted in a significant increase in gelatinization enthalpy, rising from 249.7 to 551.9 J/g, which indicates an improved resistance to gelatinization. The FTIR spectra indicated that the combination of GMS could enhance the hydrogen bonding forces and short-range ordered structure in DEC-based cakes. The rheological analysis revealed that an increase in GMS concentration resulted in enhanced viscoelasticity of DEC-based cake compared to TEC-based cakes. The DEC-based cakes exhibited a more satisfactory texture profile and higher overall acceptability than those of TEC-based cakes. Overall, these findings demonstrated that the utilization of DEC-based oleogel presented a viable alternative to commercial margarine in the development of cakes with reduced starch digestibility.

Comprehensive investigation of pressure-induced gelatinization of starches using in situ and ex-situ technical analyses

The pressure-induce gelatinization of pea starch, potato starch and corn starch was investigated by a combination of in situ and ex-situ technical analyses. According to in-situ observation of gelatinization process and the analysis of granular morphology by scanning electronic microscopy (SEM), the pressure that caused potato starch gelatinization was the highest at 600 MPa. This was followed by pea starch, and the pressure that caused the gelatinization of corn starch was the lowest at 400 MPa. In situ Raman spectral analysis revealed the molecular mechanism of starch gelatinization. This indicated that high pressure treatment resulted in the modification of the structure of the double helical polymers and the degree of a double helix of the starch crystalline varied as well. This study dynamically monitors the starch gelatinization process, aiming to better understand the gelatinization mechanism and provide a theoretical basis for the application of pressure in the starch field.

Impact of Molar Composition on the Functional Properties of Glutinous Rice Starch-Chitosan Blend: Natural-Based Active Coating for Extending Mango Shelf Life

This study investigates natural-based blends of glutinous rice starch (GRS) and chitosan (CS), varying their molar composition (0:100, 30:70, 50:50, 70:30, and 100:0) to explore their interaction dynamics. Our findings illustrate the versatility of these blends in solution and film forms, offering applications across diverse fields. Our objective is to understand their impact on coatings designed to extend the post-harvest shelf life of mangoes. Results reveal that increasing chitosan content in GRS/CS blends enhances mechanical strength, hydrophobicity, and resistance to Colletotrichum gloeosporioides infection, a common cause of mango anthracnose. These properties overcome limitations of GRS films. Advanced techniques, including FTIR analysis and stereo imaging, confirmed robust interaction between GRS/CS blend films and mango cuticles, improving coverage with higher chitosan content. This comprehensive coverage reduces mango dehydration and respiration, thereby preserving quality and extending shelf life. Coating with a GRS/CS blend containing at least 50% chitosan effectively prevents disease progression and maintains quality over a 10-day storage period, while uncoated mangoes fail to meet quality standards within 2 days. Moreover, increasing the starch proportion in GRS/CS blends enhances film density, optical properties, and reduces reliance on acidic solvents, thereby minimizing undesirable changes in product aroma and taste.

Relationships among Structure, Physicochemical Properties and In Vitro Digestibility of Starches from Ethiopian Food Barley Varieties

Studying diversity in local barley varieties can help advance novel uses for the grain. Therefore, starch was isolated from nine Ethiopian food barley varieties to determine starch structural, pasting, thermal, and digestibility characteristics, as well as their inter-relationships. The amylose content in the varieties significantly varied from 24.5 to 30.3%, with a coefficient of variation of 6.1%. The chain length distributions also varied significantly, and fa, fb1, fb2, and fb3 ranged from 26.3 to 29.0, 48.0 to 49.7, 15.0 to 15.9, and 7.5 to 9.5%, respectively. Significant variations were also exhibited in absorbance peak ratios, as well as thermal, pasting, and in vitro digestibility properties, with the latter two parameters showing the greatest diversity. Higher contents of amylose and long amylopectin fractions contributed to higher gelatinization temperatures and viscosities and lower digestibility. Structural characteristics showed strong relationships with viscosity, thermal, and in vitro digestibility properties. Cross 41/98 and Dimtu varieties are more suitable in functional food formulations and for bakery products. These results might inspire further studies to suggest target-based starch modifications and new product development.

Preparation of the black rice starch-gallic acid complexes by ultrasound treatment: Physicochemical properties, multiscale structure, and in vitro digestibility

This study aimed to investigate the multiscale structure, physicochemical properties, and in vitro digestibility of black rice starch (BRS) and gallic acid (GA) complexes prepared using varying ultrasound powers. The findings revealed that ultrasonic treatment disrupted BRS granules while enhancing the composite degree with GA. The starch granules enlarged and aggregated into complexes with uneven surfaces. Moreover, the crystallinity of the BRS-GA complexes increased to 22.73 % and formed V6-I-type complexes through non-covalent bonds. The increased short-range ordering of the complexes and nuclear magnetic resonance hydrogen (1H NMR) further indicated that the BRS and GA molecules interacted mainly through non-covalent bonds such as hydrogen bonds. Additionally, ultrasound reduced the viscoelasticity of the complexes while minimizing the mass loss of the complexes at the same temperature. In vitro digestion results demonstrated an increase in resistant starch content up to 37.60 % for the BRS-GA complexes. Therefore, ultrasound contributes to the formation of V-typed complexes of BRS and GA, which proves the feasibility of using ultrasound alone for the preparation of starch and polyphenol complexes while providing a basis for the multiscale structure and digestibility of polyphenol and starch complexes.

Influence of the structure and physicochemical properties of OSA modified highland barley starch based on ball milling assisted treatment

This study aimed to investigate the influence of ball milling assisted treatment on the degree of substitution of octenyl succinic anhydride (OSA) modified highland barley starch (HBS) and on the physicochemical properties and structure of HBS. Scanning electron microscopy (SEM) findings showed that with the increasing of ball milling time, the surface morphology of OSA modified HBS became rougher and rougher and the particle morphology and crystal structure were damaged. When the pretreatment time of ball milling was 40 min, the degree of substitution of OSA modified HBS was 1.32 times higher than that of the conventional modification method. In addition, the longer the ball milling assistant, the longer the short-range ordering of the OSA modified HBS significantly decreased, and the relative crystallinity decreased (from 16.68 % to 7.93 %), leading to a decrease in thermal stability too. However, it greatly enhanced the aging resistance and flowability. In terms of emulsification properties, the emulsification properties of OSA modified HBS increased from 60.67 % to 75.67 %. Therefore, the HBS with better freeze-thaw stability and higher degree of substitution can be prepared by ball milling pretreatment and OSA modification, which provides technical support for further development of starch resources.

Effect of Konjac Glucomannan on Structure, Physicochemical Properties, and In Vitro Digestibility of Yam Starch during Extrusion

In this study, the effect of konjac glucomannan (KGM, 0-5%) on the structure, physicochemical properties, and in vitro digestibility of extruded yam starch (EYS) was investigated. The EYS became rougher on the surface and the particle size increased as observed using scanning electron microscopy and particle size analysis. X-ray diffraction and Raman results revealed that the relative crystallinity (18.30% to 22.30%) of EYS increased, and the full width at half maxima at 480 cm-1 decreased with increasing KGM content, indicating the increment of long-range and short-range ordered structure. Differential scanning calorimetry and rheological results demonstrated that KGM enhanced thermal stability and the gel strength of EYS due to enhanced interaction between KGM and YS molecules. Additionally, a decrease in the swelling power and viscosity of EYS was observed with increased KGM content. The inclusion of KGM in the EYS increased the resistant starch content from 11.89% to 43.51%. This study provides a dual-modified method using extrusion and KGM for modified YS with high thermal stability, gel strength, and resistance to digestion.

Starch molecular structure, physicochemical properties and in vitro digestibility of Ethiopian malt barley varieties

Characterization of local varietal barley quality diversity can help boost further development of novel value-added utilization of the grain. Therefore, in this study starch was isolated from 11 Ethiopian malting barley varieties to determine starch structural, pasting, thermal and digestibility characteristics, and their inter-relationships. The varieties showed significant differences in all amylopectin chain length fractions, and the A, B1, B2 and B3 chains ranged from 25.4 to 30.1, 47.4-50.1, 14.3-16.0 and 7.8-9.0 %, respectively. The varieties also exhibited significant variation in amylose content, relative crystallinity, absorbance peak ratios, pasting and thermal properties. Moreover, on average about 83 % raw starch of the varieties was classified as slowly digestible and resistant, whereas after gelatinization this was reduced to 9 %. Molecular and crystalline structures were strongly related to pasting properties, thermal characteristics and in vitro digestibility of the starches. The study provides information on some starch quality characteristics and the inter-relationships among the parameters, and might inspire further studies to suggest possible target-based starch modifications, and future novel utilization of barley. More studies are required to investigate the association of starch quality parameters with malting quality attributes.

Improvement of in vitro digestibility and thermostability of debranched waxy maize starch by sequential ethanol fractionation

This study aimed to improve the in vitro digestibility and thermostability of debranched waxy maize starch (DWMS) by sequential fractionation. Waxy maize starch was debranched by pullulanase, followed by sequential precipitation through controlling the ratio of starch supernatants to ethanol at 1:0.5, 1:1, and 1:1.5 (v/v). Subsequently the structural, thermal, in vitro digestive properties of DWMS were investigated. In vitro digestion results showed that the secondary ethanol fractionation of 1:1 on the basis of the initial fractionation (1:0.5) induced a significant higher amount of slowly digestive starch (SDS, 30.0 %) and resistant starch (RS, 58.6 %) amongst all three fractions, along with the highest peak temperature (Tp, 106.4 °C) and the highest decomposition value (Td, 310.0 °C) in calorimetric (DSC) and thermogravimetry (TGA) measurements. Chain length distribution, surface morphology, and laser confocal micro-Raman spectroscopy (LCM-Raman) analyses revealed that medium (degree of polymerization, DP 13- 36) and long chains (DP ≥37) respectively constituting 72.0 % and 10.2 % of DWMS resulted in the formation of spheroidal crystallites with higher homogeneity and more ordered short-range structures. Overall, this work confirmed that ethanol fractionation is an efficient method for improving the in vitro digestibility and heat stability of waxy maize starch.

Enhancing physicochemical, rheological properties, and in vitro rumen fermentation of starch with Melastoma candidum D. Don fruit extract

The utilization of polyphenol-modified starch in ruminants has not undergone extensive exploration. This study aimed to investigate the impact of the complex formed between starch and Melastoma candidum D. Don fruit extract on physicochemical properties, phenol release kinetics in various buffers simulating the gastrointestinal tract, methane production, and post-rumen digestibility. The interaction between starch and M. candidum D. Don fruit extract significantly (p < 0.001) increased resistant starch and particle size diameter. The maximum phenolic release from complex between starch and M. candidum D. Don fruit extract, due to gastrointestinal tract-simulated buffers, ranged from 22.96 to 34.60 mg/100 mg tannic acid equivalent. However, rumen and abomasum-simulated buffers released more phenolic content, whereas the intestine-simulated buffer showed higher antioxidant activity (ferric ion-reducing antioxidant power). Furthermore, complex between starch and M. candidum D. Don fruit extract significantly decreased dry matter rumen digestibility (p < 0.001) and maximum methane gas production (p < 0.001).

Characteristics of physicochemical properties, structure and in vitro digestibility of seed starches from five loquat cultivars

Starch plays a pivotal role in food and other industries, necessitating the exploration of new starch sources to cater the substantial requirement. This study delved into the variations in the physicochemical properties, structure attributes and in vitro digestibility of seed starches extracted from five distinct loquat cultivars (Eriobotrya japonica L.). The starch extraction yield of loquat seeds was found to be 45.2 % as an average. Loquat seed starches were designated as having high-amylose starch (>50 %). The starch granules exhibited similar shapes, but granular size significantly varied across the cultivars. Loquat starches presented a C-type crystalline pattern with relative crystallinity from 17.14 % to 21.06 %. The short-range ordered structure of the starches differed with loquat cultivars. The swelling power, solubility and amylose leaching of loquat starches increased with increasing temperature, significantly varying among different cultivars. Gelatinization parameters exhibited significant variations among the loquat starches. Different loquat starches exhibited pronounced variations in paste clarity, water and oil absorption capacity. Marked differences were detected in proportions of rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) across the five cultivars, with RS being particularly prominent fraction with an average of 84.30 %. These compressive findings offer valuable insights into the potential application of loquat seed starches in the formulation of foods and various industrial products.

Effect of continuous instant pressure drop treatment on the rheological properties and volatile flavor compounds of whole highland barley flour

Continuous instant pressure drop (CIPD) treatment effectively reduces microbial contamination in whole highland barley flour (WHBF). Base on it, this study further investigated its effects on flour properties (especially rheological properties) and volatile compounds (VOCs) profile of WHBF, and compared it with that of ultraviolet-C (UV-C), ozone and hot air (HA) treatments. The results showed that the damaged starch content (6.0%) of CIPD-treated WHBF was increased, leading to a rough surface and partial aggregation of starch particle, thereby increasing the particle size (18.06 μm of D10, 261.46 μm of D50 and 534.44 μm of D90). Besides, CIPD treatment exerted a positive influence on the structure and rheological properties of WHBF, including an elevation in pasting temperature and viscosity. Notably, CIPD-treated WHBF exhibited higher storage modulus and loss modulus compared to the other three groups of sterilization treatments, contributing to the formulation of a better-defined and stable gel strength (tan δ = 0.38). UV-C and ozone, as cold sterilization techniques, also induced alterations in specific characteristics of WHBF. UV-C treatment led to changes in WHBF's crystallinity, while ozone treatment caused modifications in the secondary protein structure of WHBF. A total of 68 VOCs were identified in raw WHBF (including 3 acids, 19 alcohols, 25 aldehydes, 1 alkene, 8 esters, 2 ethers, 3 furans, and 7 ketones). The maximum flavor-contributing VOC in CIPD-treated WHBF remained dimethyl sulfide monomer (cabbage aroma), consistent with the raw WHBF. Conversely, in HA-treated WHBF, the maximum flavor-contributing VOC shifted to 2-furanmethanethiol monomer (roasted coffee aroma), altering the initial flavor presentation. These findings will provide strong support for the application of CIPD technology in the powdery foods industry.

Structural and Functional Properties of Porous Corn Starch Obtained by Treating Raw Starch with AmyM

Porous starch is attracting considerable attention for its high surface area and shielding ability, properties which are useful in many food applications. In this study, native corn starch with 15, 25, and 45% degrees of hydrolysis (DH-15, DH-25, and DH-45) were prepared using a special raw starch-digesting amylase, AmyM, and their structural and functional properties were evaluated. DH-15, DH-25, and DH-45 exhibited porous surface morphologies, diverse pore size distributions and pore areas, and their adsorptive capacities were significantly enhanced by improved molecular interactions. Structural measures showed that the relative crystallinity decreased as the DH increased, while the depolymerization of starch double helix chains promoted interactions involving disordered chains, followed by chain rearrangement and the formation of sub-microcrystalline structures. In addition, DH-15, DH-25, and DH-45 displayed lower hydrolysis rates, and DH-45 showed a decreased C∞ value of 18.9% with higher resistant starch (RS) content and lower glucose release. Our results indicate that AmyM-mediated hydrolysis is an efficient pathway for the preparation of porous starches with different functionalities which can be used for a range of applications.

Influence pathways of nanocrystalline cellulose on the digestibility of corn starch: Gelatinization, structural properties, and α-amylase activity perspective

This work focused on the pathways by which NCC regulated the digestibility of corn starch. The addition of NCC changed the viscosity of the starch during pasting, improved the rheological properties and short-range order of the starch gel, and finally formed a compact, ordered, and stable gel structure. In this respect, NCC affected the digestion process by changing the properties of the substrate, which reduced the degree and rate of starch digestion. Moreover, NCC induced changes in the intrinsic fluorescence, secondary conformation, and hydrophobicity of α-amylase, which lowered its activity. Molecular simulation analyses suggested that NCC bonded with amino acid residues (Trp 58, Trp 59, and Tyr 62) at the active site entrance via hydrogen bonding and van der Waals forces. In conclusion, NCC decreased CS digestibility by modifying the gelatinization and structural properties of starch and inhibiting α-amylase activity. This study provides new insights into the mechanisms by which NCC regulates starch digestibility, which could be beneficial for the development of functional foods to tackle type 2 diabetes.

Effects of lactic acid bacteria fermentation on the physicochemical and structural characteristics of starch in blends of glutinous and japonica rice

In this study, the effects of lactic acid bacteria (LAB) fermentation on the physicochemical and structural characteristics of mixed starches in blends of glutinous and japonica rice were investigated. Five starter cultures improved in varying degrees the hydration ability, transparency, and freeze-thaw stability of the mixed starches. Mixed starch I, prepared by fermentation of Lactobacillus acidophilus HSP001, exhibited optimal water-holding capacity, solubility, and swelling power. In comparison, mixed starches V and III involved fermentation of L. acidophilus HSP001 and Latilactobacillus sakei HSP002, using ratios of 2:1 and 1:1 to achieve higher transparency and freeze-thaw stability, respectively. The LAB-fermented, mixed starches exhibited excellent pasting properties due to their high peak viscosities and low setback values. Moreover, the viscoelasticity of mixed starches III-V, prepared by compound fermentation of L. acidophilus HSP001 and L. sakei HSP002 in ratios of 1:1, 1:2, and 2:1, respectively, proved superior to their single strain fermentation counterparts. Meanwhile, LAB fermentation resulted in reduced gelatinization enthalpy, relative crystallinity, and short-range ordered degree. Thus, the effects of five LAB starter cultures on mixed starches were inconsistent, but these results provide a theoretical basis for the application of mixed starches. PRACTICAL APPLICATION: Lactic acid bacteria was used to ferment blends of glutinous and japonica rice. Fermented mixed starch had better hydration, transparency, and freeze-thaw stability. Fermented mixed starch exhibited nice pasting properties and viscoelasticity. LAB fermentation corroded starch granules, leading to the decrease of ΔH. Relative crystallinity and short-range order of fermented mixed starch decreased.

Effect of Tartary Buckwheat Bran Substitution on the Quality, Bioactive Compounds Content, and In Vitro Starch Digestibility of Tartary Buckwheat Dried Noodles

This study aimed to investigate the impact of partial replacement of Tartary buckwheat flour (TBF) with Tartary buckwheat bran flour (TBBF) on the quality, bioactive compounds content, and in vitro starch digestibility of Tartary buckwheat dried noodles (TBDNs). When the substitution of TBBF was increased from 0 to 35%, the cooking and textural properties decreased significantly (p < 0.05), while the content of bioactive compounds (phenolic, flavonoids and dietary fiber) increased significantly (p < 0.05). In addition, the substitution of TBBF decreased the starch digestibility of TBDNs. A 10.4% reduction in eGI values was observed in the TBDNs with 35% TBBF substitution compared to the control sample. The results of differential scanning calorimetry showed that with the increase of TBBF, TBDNs starch became more resistant to thermal processing. Meanwhile, the X-ray diffraction and Fourier transform infrared spectroscopy results revealed that the long- and short-range ordered structures of TBDN starch increased significantly (p < 0.05). Furthermore, the substitution of TBBF decreased the fluorescence intensity of α-amylase and amyloglucosidase. This study suggests that replacing TBF with TBBF could produce low glycemic index and nutrient-rich TBDNs.

Effect of mulberry leaf polysaccharides on the baking and staling properties of frozen dough bread

BACKGROUND

Deterioration in frozen dough bread easily occurs in store, resulting in tremendous economic waste. Therefore, it is imperative to find natural additives to improve storage staling. The effects of mulberry leaf polysaccharides (MLP) were studied in terms of baking, retrogradation and microstructural aspects in frozen dough bread.

RESULTS

The incorporation of MLP improved the specific volume and reduced the hardness of bread during room storage, with 1% MLP showing the best results. The results of X-ray diffraction and Fourier transform infrared spectroscopy showed that crystallinity was decreased and the formation of double helical structure was inhibited with the incorporation of MLP. Meanwhile, the results of low-field nuclear magnetic resonance demonstrated that the addition of MLP was advantageous for retarding water migration and distribution, with reduced water loss. It can be seen intuitively from scanning electron microscopy that MLP improved the gluten network with a smoother and flatter system.

CONCLUSION

MLP improved the quality of bread during storage and delayed the degradation of internal structure, and can be used as an effective natural additive to improve the storage stability of baked food. 1% MLP showed the best results. © 2022 Society of Chemical Industry.

Analysis of starch structure and functional properties of tetraploid wheat (Triticum turgidum L.) with differing waxy protein composition

BACKGROUND

An increased demand for food has mirrored the increasing global population. Obesity and diabetes are two disorders induced by poor eating choices. Consequently, there is an urgent need to develop modified foods that can ameliorate such illnesses. The objective of this study was to explore the effect of Waxy genes on the structural and functional properties of starch, with the aim of improving food quality. Wild-type tetraploid wheat was compared with three mutants with different Waxy gene combinations.

RESULTS

The proportion of B-type granules was higher in the mutants than in the wild-type (Wx-AB), and there were significant changes in the starch granule size, number, and phenotype in the Wx free mutant (Wx-ab). The lowest branch chain length was observed in Wx-ab, whereas Wx-AB had the highest branch chain length of DP ≥ 37. Wx-ab had the highest degree of crystallinity. The crystallinity trend followed the order Wx-ab>Wx-Ab>Wx-aB>Wx-AB. The amount of slowly digestible starch (SDS) was higher in native, gelatinized, and retrograded starch in the mutant. The amount of retrograded starch was closer to gelatinized starch than to native starch.

CONCLUSION

Waxy proteins make a substantial contribution to starch structure. A lack of waxy proteins reduced the unit chains markedly compared with the control. Waxy proteins significantly affected the smaller and longer chains of starch. The lines with differing waxy composition had different effects on food digestion. The Wx-AB in native starch and Wx-Ab in gelatinized starch can control obesity and diabetes by slow-digesting carbohydrates and high resistance to digestion. © 2022 Society of Chemical Industry.

Understanding the texture and digestibility attributes of rice noodles supplemented with common vetch starch

The effects of common vetch starch (CVS) substitution on rice noodle quality were investigated, aiming to improve their texture and reduce starch digestibility. The CVS had larger granule sizes, higher amylose content and more long branch chains compared with rice starch (RS). When the CVS substitution level was 20 %, the rice noodles had the best texture quality, as the mixtures with more total starch and amylose could form denser gel structures. Moreover, the starch chains were easier to rearrange to form double helix ordered structures, resulting in a slower digestion rate. With the further increase of CVS, the noodle structure weakened and the starch digestion rate increased. This was due to the formation of looser gel structures and less ordered structures as RS granules could be easily separated into different parts by large amount of CVS with larger granule sizes, and RS with more short chains tended to be cross-linked with RS during retrogradation. With increasing CVS substitution level, the estimated glycemic index (eGI) of rice noodles decreased and then tended to be stable. Therefore, appropriate CVS substitution could improve the texture quality of rice noodles and reduce the eGI value, and the best substitution level was 20 %.

Starch-lauric acid complex-stabilised Pickering emulsion gels enhance the thermo-oxidative resistance of flaxseed oil

Hydrophobic-modified starch complexes have the potential to form Pickering emulsions and improve the oxidative stability of flaxseed oil. Here, V-type starch-lauric acid complexes (SLACs) were fabricated via solid encapsulation within 0.5-12 h and applied in flaxseed oil Pickering emulsions. Complexing index, X-ray diffraction and differential scanning calorimetry analyses confirmed that the degree of complexation increased with the reaction time. Pickering emulsion gels stabilised by SLACs generated with reaction times of 6 h and 12 h exhibited good storage stability and high yield stress, G' values and apparent viscosity. Confocal laser scanning microscopy and cryo-scanning electron microscopy revealed a gelation mechanism involving increased interface roughness and enhanced droplet-droplet interaction. In comparison to pure flaxseed oil, higher thermo-oxidative resistance was observed at 130 °C, with a markedly longer oxidation induction for emulsions and emulsion gels stabilised by SLACs. Our findings could assist in the design of hydrophobic-modified starch and provide a new paradigm for delaying oil oxidation.

Mechanisms Underlying the Formation of Amylose- Lauric Acid-β-Lactoglobulin Complexes: Experimental and Molecular Dynamics Studies

The aim of the present study was to reveal the mechanisms underlying the formation of ternary complexes with a model system of amylose (AM), lauric acid (LA), and β-lactoglobulin (βLG) using experimental studies and molecular dynamics (MD) simulations. Experimental analyses showed that hydrophobic interactions and hydrogen bonds contributed more than electrostatic forces to the formation of the AM-LA-βLG complex. MD simulations indicated that interactions between AM and βLG through electrostatic forces and hydrogen bonds, and to a less extent van der Waals forces, and interactions between AM and LA through van der Waals forces, were mostly responsible for complex formation. The combination of experimental results and MD simulations has provided new mechanistic insights and led us to conclude that hydrophobic interactions, van der Waals forces between AM and LA, and van der Waals forces and hydrogen bonds between AM and βLG were the main driving forces for the formation of the AM-LA-βLG complex.

Effect of annealing using plasma-activated water on the structure and properties of wheat flour

In this study, wheat flour (WF) was modified by annealing (ANN) using plasma-activated water (PAW) for the first time. Compared with WF and DW-WF, the results of scanning electron microscopy (SEM) and particle-size analysis showed that the granule structure of wheat starch in PAW-WF was slightly damaged, and the particle size of PAW-WF was significantly reduced. The results of X-ray diffraction and Fourier transforming infrared spectroscopy indicated that PAW-ANN could reduce the long-range and short-range order degrees of wheat starch and change the secondary structure of the protein in WF, in which the content of random coils and α-helices was significantly increased. In addition, the analysis of solubility, viscosity, and dynamic rheological properties showed that PAW-ANN improved the solubility and gel properties of WF and decreased its viscosity properties and short-term regeneration. PAW-ANN, as a green modification technology, has the potential for further application in WF modification, as well as in the production of flour products.

Multi-Scale Structures and Functional Properties of Quinoa Starch Extracted by Alkali, Wet-Milling, and Enzymatic Methods

The purpose of this study is to investigate the effects of starch extraction methods (alkali, wet-milling, and enzymatic) on the multi-scale structures and functional properties of quinoa starch. When the enzymatic method was compared with alkali and wet-milling, it showed higher protein content (2.39%), larger size of aggregated granules (44.1 μm), higher relative crystallinity (29.6%), scattering intensity (17.8 α.u.), absorbance ratio of 1047/1022 (0.9), single and double helical content (8.2% and 23.1%), FWHM ratio (2.1), and average molecular weight and radius of gyration (1.58 × 107 g/mol and 106.8 nm), respectively. Similarly, quinoa starch by enzymatic extraction had a higher onset (82.1 °C), peak (83.8 °C), and conclusion (86.3 °C) temperatures, as well as an enthalpy change (6.7 J/g). It further showed maximum hardness (238.8 N), gumminess (105.6 N), chewiness (80.2 N), SDS content (7.5% of raw and 4.8% of cooked), and RS content (15.5% of raw and 13.9% of cooked), whereas it contained minimum RDS content (77.1% of raw and 81.9% of cooked). The results suggest that extraction of starch by the enzymatic method could be a viable approach to retain the native structure of starch and may eventually improve the glycemic response.

Study of Noodle Quality Based on Protein Properties of Three Wheat Varieties

Waxy wheat offers unique benefits in food processing, including improving the smoothness and performance of the product. However, waxy wheat is not yet commercially available. The protein characteristics, including the protein content, subunit distribution, secondary structure, chemical interactions, and microstructure of the gluten, were explored to realize the full potential of waxy wheat. The results showed that the noodles prepared from waxy wheat had a gentle and glutinous texture compared with GY2018 and YM13. Partial-waxy and waxy wheat had a lower gluten index and glutenin macropolymer (GMP) content than GY2018, indicating a reduced gluten strength. Confocal laser scanning microscopy (CLSM) images showed that the starch granules were not securely attached to the partial-waxy and waxy wheat protein matrix. In addition, the waxy protein chains appeared more elongated and they weakened the protein network. In particular, HMW-GS subunit 2 + 12 may be the essential cause of the weak dough from SKN1. Compared with GY2018 and YM13, SKN1 had the highest number of free sulfhydryl groups. Rather than ionic bonds, hydrophobic interactions increased the gluten network in GY2018, YM13, and SKN1. The weak molecular forces in the gluten will result in a soft noodle texture.

Grain Yield Performance and Quality Characteristics of Waxy and Non-Waxy Winter Wheat Cultivars under High and Low-Input Farming Systems

Waxy starch with a modified amylose-to-amylopectin ratio is desired for a range of applications in food and non-food industries; however, yield performance and grain quality characteristics of waxy wheat cultivars are usually inferior in comparison to advanced non-waxy cultivars. In this study, we compared waxy (‘Eldija’, ‘Sarta’) and non-waxy (‘Skagen’, ‘Suleva DS’) winter wheat cultivars grown under high and low-input farming systems over two cropping seasons by evaluating their yield and grain quality, including flour, dough, and starch physicochemical properties. The yield of waxy cv. ‘Sarta’ was significantly lower compared to the non-waxy cultivars across all trials; however, waxy cv. ‘Eldija’ had a similar yield as non-waxy cultivars (except under high-input conditions cv. ‘Skagen’). Moreover, no significant differences were observed between protein and gluten content of waxy and non-waxy cultivars. Low amylose content typical for waxy wheat cultivars highly correlated (r ≥ 0.8) with lower falling number, flour yield and sedimentation values, lower nitrogen % used for grain, higher flour water absorption and flour particle size index. In general, properties dependent on starch structure demonstrated consistent and significant differences between both starch types. The prevailing heat waves during the grain filling period decreased grain test weight but increased protein and gluten content and caused gluten to be weaker. Dough development time at these conditions became longer, dough softening lowered and starch content decreased, but A-starch, starch peak and final viscosity values increased. Low-input farming had a negative effect on grain yield, grain nitrogen uptake and grain test weight but increased phosphorus content in grain. The unique dough mixing properties of waxy cultivar ‘Eldija’ suggest that it could be used in mixtures along with non-waxy wheat for dough quality improvement.

Vigna subterranea (L.) Verdc Starch-Soluble Dietary Fibre Potential Nanocomposite: Thermal Behaviour, Morphology and Crystallinity

Bambara groundnut (BGN) starch-soluble dietary fibre nanocomposite (STASOL) was manufactured by grafting 1.95 g BGN soluble dietary fibre (BGN-SDF) onto 15 g BGN starch (BGNS). The particle sizes, functional groups, crystallinity, morphology and thermal properties of BGNS, BGN-SDF and STASOL were studied using a Zetasizer, Fourier transform infrared, X-ray diffraction, scanning electron microscope and differential scanning calorimetry, respectively. STASOL had a particle size and conductivity of 74.01 nm and −57.3 mV, respectively. BGN-SDF and STASOL were amorphous and BGNS was classified as type C starch, typical of legumes. The biopolymers had functional groups in the regions 2900–3600, 1600–1642, 900–1200 and 800–1300 cm−1, which could be attributed to the vibrational stretching of OH groups, vibration of OH groups in the non-crystalline region of starch, vibration of C-O, C-C and C-H-O bonds and the vibration of C-O and C-C bonds, respectively. BGNS had smooth, oval structures while BGN-SDF and STASOL exhibited irregular, polygonal morphologies. STASOL was the most thermally stable biopolymer, disintegrating at 293 °C, therefore suggesting that it would find use in high-temperature food applications such as baking.