Structural characteristics and physicochemical properties of field pea starch modified by physical, enzymatic, and acid treatments

Effects of Aspergillus flavus infection on multi-scale structures and physicochemical properties of maize starch during storage

This study systematically analyzed the effect of Aspergillus flavus infection on the maize starch multi-scale structure, physicochemical properties, processing characteristics, and synthesis regulation. A. flavus infection led to a decrease in the content of starch, an increase in the content of reactive oxygen species (ROS) and malondialdehyde (MDA), a significant decrease in the activities of peroxidase (POD) and superoxide dismutase (SOD). In addition, A. flavus infection had a significant destructive effect on the double helix structure, relative crystallinity and lamellar structure of starch, resulting in the reduction of starch viscosity, affecting the viscoelastic properties of starch, and complicating the gel formation process. However, the eugenol treatment group significantly inhibited the growth of A. flavus during maize storage, protecting the multi-scale structure and processing characteristics of maize starch from being damaged. Transcriptome analysis showed that genes involved in carbohydrate synthesis in maize were significantly downregulated and genes involved in energy synthesis were significantly upregulated, indicating that maize converted its energy storage into energy synthesis to fight the invasion of A. flavus. These results of this study enriched the mechanism of quality deterioration during maize storage, and provide theoretical and technical support for the prevention of A. flavus infection during maize storage.

Enhancing the nonlinear rheological property and digestibility of mung bean flour gels using controlled microwave treatments: Effect of starch debranching and protein denaturation

In this study, we examined the possibility of using industrial microwave processing to enhance the gelling properties and reduce the starch digestibility of mung bean flour (MBF). MBF (12.6 % moisture) was microwaved at a power of 6 W/g to different final temperatures (100-130 °C), and then its structural and functional properties were characterized. The microwave treatment had little impact on the crystalline structure or amylose content of the starch, but it roughened the starch granule surfaces and decreased the short-range ordered structure and degree of branching. In addition, the extent of mung bean protein denaturation caused by the microwave treatment depended on the final temperature. Slightly denaturing the proteins (100 °C) did not affect the nature of the gels (protein phase dispersed in a starch phase) but the gel network became more compact. Moderately denaturing the proteins (110-120 °C) led to more compact and homogeneous starch-protein double network gels. Excessive protein denaturation (130 °C) caused the gel structure to become more heterogeneous. As a result, the facilitated tangles between starch chains by more linear starch molecules after debranching, and the protein network produced by moderate protein denaturation led to the formation of stronger gel and the improvement of plasticity during large deformation (large amplitude oscillatory shear-LAOS). Starch recrystallization, lipid complexion, and protein network retard starch digestion in the MBF gels. In conclusion, an industrial microwave treatment improved the gelling and digestive properties of MBF, and Lissajous curve has good adaptability in characterizing the viscoelasticity of gels under large deformations.

The effect of heat moisture treatment times on physicochemical and digestibility properties of adzuki bean, pea, and white kidney bean flours and starches

The effects of heat moisture treatment (HMT) times on the physicochemical properties of three bean flours and their starch were analyzed. The colors of L*, b* and ΔE values increased significantly with time. The adzuki bean and pea flours showed better WAI and SP, and better gelation of starch at 2 h. The rheological properties of mixed HMT dough (3:7) exhibited the typical solid-like weak gel behavior. HMT had a significantly decreased on the pasting viscosity of bean flour starch with treated time. HMT caused the starch granules damage, but did not radically change the crystal type. FTIR results showed more proteins attached to the surface of starch granules, and the short-range molecular order decreased the DO at 2 h. In vitro digestibility inferred that RDS converted into SDS and RS. These results indicated that HMT significantly affected the digestibility and physicochemical properties of bean flours.

V-type granular starches prepared by maize starches with different amylose contents: An investigation in structure, physicochemical properties and digestibility

V-type granular starches (VGSs) were prepared via an ethanol-alkaline (EA) method using maize starch with different amylose contents, specifically, high amylose (HAM), normal maize starch (MS), and waxy maize starch (WS). The X-ray diffraction pattern of the native starch was completely transformed into a V-type pattern after the EA treatment, indicating a structural change in the starch granules. The VGSs prepared by HAM had highest relative crystallinity (31.8°), while the VGSs prepared by WS showed amorphous diffraction pattern. Excessive NaOH, however, would disrupt the formation of V-type structures and cause granular shape rupture. The quantity of double-helical structures, particularly those formed by amylopectin at the starch granules' periphery, significantly decreased. Conversely, single-helical structures formed by amylose increased. A notable rise in the relative crystallinity of V crystals. Four VGS samples, characterized by granular integrity, were chosen for the next investigation of physicochemical and digestive properties. VGS prepared from HAM exhibited higher granular integrity, lower cold-water swelling extent (59.0 and 161.0 cP), improved thermal stability (the value of breakdown as lower as 57.67 and 186.67 cP), and higher resistance to digestion (RS content was up to 10.38 % and 9.00 % higher than 5.86 % and 5.66 % of VGS prepared from WS and MS). The results confirmed that amylose content has a substantial impact on the microstructural and physicochemical properties of VGSs.

Structural modification of starch and protein: From the perspective of gelatinization degree of oat flour

To clarify the relationship between gelatinization degree and structure characteristics, oat kernels were roasted to different gelatinization degree of 15 %-90 % based on tempering water content of 22.5 %-35 %, and the structure characteristics of starch and protein were evaluated. The results showed that the increased gelatinization degree dependent on tempering water content promoted protein aggregation on the surface of starch particles, forming larger aggregates with molecular weight >100 kDa. Oat kernels presented a dense starch gel network structure induced by gelatinized starch. Partial gelatinization of starch led to a decrease in pasting viscosities (setback viscosity, 3.91 Pa·s-1.59 Pa·s) and enthalpy (5.12 J/g-0.11 J/g). With the increase of gelatinization degree, the starch crystal structure conversed from A + V type to V type, accompanied by the formation of starch-lipid complexes and a decrease of relative crystallinity (22.28 %-8.72 %). Moreover, 50 % gelatinized oat flour possessed the highest β-sheet structure (38.04 %), but a decrease in surface hydrophobicity and an increase in endogenous fluorescence intensity were found in oat flour of gelatinization degree >50 %. This study provided a theoretical reference for the application of oat flour with different gelatinization degrees to match suitable products.

The multi-scale structure changes of γ-ray irradiated potato starch to mitigate pasting/digestion properties

The comprehensive understanding of multi-scale structure of starch and how the structure regulates the pasting/digestion properties remain unclear. This work investigated the effects of γ-ray irradiation with different doses on multi-scale structure and pasting/digestion properties of potato starch. Results indicated that γ-ray at lower doses (<20 kGy) had little effect on micromorphology of starch, increased mainly the amylose content and the thickness of amorphous region while decreased crystallinity, double helix content and lamellar ordering. With the increase of dose, the internal structure of large granules was destroyed, resulting in the depolymerization of starch to form more short-chains and to reduce molecular weight. Meanwhile, amylose content decreased due to the depolymerization of amylose. The enhanced double helix content, crystallinity, lamellar ordering and structural compactness manifested the formation of the thicker and denser starch structure. These structure changes resulted in the decreased viscosity, the increased stability and anti- digestibility of paste.

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.

Impact of ultrasound treatment on the physicochemical and rheological properties of acid hydrolyzed sorghum starch

The present study aimed to evaluate the influence of ultrasonication on the physicochemical properties of native and acid-hydrolyzed white sorghum starch. Sorghum starch exhibited improved freeze-thaw stability, solubility, swelling power, and paste clarity after mild sonication. Starches sonicated at 30 % amplitude for 10 and 20 min increased the peak viscosity to 249 and 240 BU, gel firmness to 140.23 and 131.62 (g), ΔH to 13.4 and 13.1 (J/g), crystallinity to 29.51 and 29.10 (%), double helix content to 1.11 and 1.07 and degree of ordered structures to 1.16 and 1.09. The sonicated dual-treated samples (sonicated-acid hydrolyzed) exhibited reduced swelling power, peak viscosity, gelatinization temperatures and gel firmness. In contrast, the solubility, paste clarity, ΔH, percentage of crystallinity, double helix content and degree of ordered structures improved. Ultrasonic treatment made cracks and holes in the granule surface, whereas dual-treated starches were more porous and rougher, with deep depressions. All sorghum starches displayed shear-thinning behavior (n < 1). The pseudoplastic behavior and consistency indices of the starch paste decreased with increasing sonication time and amplitude. The G' was always higher than G" and tanδ was <1 for all samples, indicating a more solid/elastic behavior. The increased sonication time and amplitude, as well as the dual-treatment, caused the gel to become more susceptible to shear forces, which resulted in a decrease in G' and G" and an increase in tanδ.

Effects of zucchini polysaccharide on pasting, rheology, structural properties and in vitro digestibility of potato starch

Zucchini polysaccharide (ZP) has a unique molecular structure and a variety of biological activities. This study aimed to evaluate the effects of ZP (1, 2, 3, 4 and 5 %, w/w) on the properties of potato starch (PS), including pasting, rheological, thermodynamic, freeze-thaw stability, micro-structure, and in vitro digestibility of the ZP-PS binary system. The results showed that the appearance of ZP significantly reduced the peak, breakdown, final and setback viscosity and prolonged the pasting temperature of PS, whereas increased the trough viscosity. The tests of rheological showed that ZP had a damaging effect on PS gels. Meanwhile, the results of thermodynamic and Fourier transform infrared exhibited that the presence of ZP significantly retarded the retrogradation of PS, especially at a higher levels. The observation of the microstructure exhibited that ZP significantly altered the microscopic network structure of the PS gels, and ZP reduced the formation of the gel structure. Besides, ZP postponed the retrogradation process of PS gels. Moreover, ZP weakened the freeze-thaw stability of the PS gel. Furthermore, ZP also can decrease the digestibility and estimated glycemic index (eGI) value of PS from 86.04 % and 70.89 to 77.67 % and 65.22, respectively. Simultaneously, the addition of ZP reduced the rapidly digestible starch content (from 25.09 % to 16.59 %) and increased the slowly digestible starch (from 24.99 % to 26.77 %) and resistant starch content (from 49.92 % to 56.64 %). These results have certain guiding significance for the application of ZP in starch functional food.

The changed multiscale structures of tight nut (Cyperus esculentus) starch decide its modified physicochemical properties: The effects of non-thermal and thermal treatments

Non-thermal dielectric barrier discharge plasma (DBDP) and four thermal treatments, including baking (BT), high pressure cooking (HPC), radio frequency (RF) and microwave (MW) were applied to modify the structural and physicochemical properties of Cyperus esculentus starch (CES). The results showed that the thermal treatments remarkably disordered the crystalline structures of CES through weakening the double-helix conformation of amylopectin, while DBDP caused much more gentle influence on the starch structures than them. Specifically, MW induced the high-frequency displacement of polar molecules and intensive collisions between starch and water molecules, causing the largest stretching and swelling extents of amylopectin, resulting in the highest pasting and rheological viscosity of CES in four thermal treatments. As DBDP did not favor the aggregation of amylopectin chains, the deaggregated starch chains promoted the hydration effects with water molecules, boosting the final pasting viscosity, apparent rheological viscosity, freeze-thaw stability and digestion velocity of CES. Besides, the gelatinization-retrogradation process in the thermal treatments regulated starch digestion velocity and produced type III resistant starch in CES. Conclusively, the modified physicochemical properties of CES resulted from the altered molecular structures of starch by the applied treatments.

Interaction between potato starch and barley β-glucan and its influence on starch pasting and gelling properties

The interactions between potato starch (PtS) and barley β-glucan (BBG) were investigated by preparing PtS-BBG mixtures, and the pasting, rheological, gelling and structural properties were evaluated. Rapid viscosity analysis suggested that BBG reduced the peak and breakdown viscosity, while increasing the setback viscosity of PtS. PtS-12%BBG showed the lowest leached amylose content (12.02 ± 0.36 %). The particle size distribution pattern of PtS was not changed with the addition of BBG, and the median diameter of PtS-12%BBG (88.21 ± 0.41 μm) was smaller than that of PtS (108.10 ± 6.26 μm). Rheological results showed that PtS and PtS-BBG gels exhibited weak gel behaviors, and BBG could remarkably affect the elastic and viscous modulus of PtS gels. Textural analysis suggested that the strength and hardness of PtS gels were increased when few BBG (<6 %, w/w) was present in the system. BBG improved the freeze-thaw stability of PtS gels. Structural analysis indicated that hydrogen bonds were the main force in the PtS-BBG systems. These results indicated that BBG interacted with starch via hydrogen bonds, which delayed starch gelatinization and improved gelling properties of PtS gels. Overall, this study gained insights into starch-polysaccharide interactions and revealed the possible applications of BBG in food processing.

Comparison of structures and properties of gels formed by corn starch with fresh or dried Mesona chinensis polysaccharide

Starch is a major dietary carbohydrate, but its digestion properties need to be improved. Mesona chinensis polysaccharides (MCPs) had a unique function in improving the flocculation performance of starch. This study investigated the effects of adding Mesona chinensis polysaccharide extracted from wet fresh and dry plants with one-year storage, namely WMCP and DMCP, on the physicochemical properties and digestion kinetics of corn starch(CS). The composition analysis showed both WMCP and DMCP were an acidic heteropolysaccharide rich in galacturonic acid and galactose, whereas showed different average main fraction molecular weights (Mw) of 47.36 kDa and 42.98 kDa, respectively. In addition, WMCP showed higher yield, purity and better physicochemical properties to CS than DWCP. Thermal analysis showed WMCP decreased more gelatinization temperatures and enthalpy of CS, and increased more freeze-thaw stability, water holding capacity, and textural parameters of CS gels than DMCP. Structural analysis revealed WMCP induced more changes in crystallinity, short-range order, and microstructure of CS, which inhibited retrogradation than DMCP. In vitro digestion assays demonstrated WMCP addition significantly increased higher resistant starch content by altering starch-starch and starch-MCP interactions than DWCP. Overall, MCPs addition beneficially modulated CS properties and digestion kinetics, providing a novel way to improve starch functionalities. Moreover, WMCP had more advantages to be chosen to form hydrocolloid with CS than DMCP.

Mung Bean Starch and Mung Bean Starch Sheet Jelly: NaCl-Based Characteristics Variation

Empirical evidence indicates that NaCl can improve the quality of mung bean starch sheet jelly (MBSS) when properly incorporated. In this study, by comparison with a sample without NaCl, the influences of NaCl (1.5-8%, w/w) on the physicochemical and structural properties of mung bean starch (MBS) and the quality of MBSS were investigated. MBS with added NaCl had greater gelatinization temperature and pasting parameters but lower gelatinization enthalpy than native MBS. With the addition of NaCl, the drying rate of MBSS first accelerated and then declined in the oven-drying process. The addition of NaCl improved the cooking properties of MBSS but decreased the hardness of cooked MBSS. Rheological results implied that the linear viscoelastic region of cooked MBSS decreased with the NaCl addition, and the storage modulus and tan δ were more frequency-dependent than the loss modulus of cooked MBSS. The addition of NaCl gradually increased the toughness of dried MBSS and the overall acceptability of cooked MBSS. Furthermore, NaCl decreased the structure order degree of starch in MBSS. Correlation analysis demonstrated that the quality of MBSS had a significant correlation with the molecular and lamellar order of starch. Overall, NaCl could improve the quality of MBSS by regulating the thermal, gelatinizing, and structural properties of MBS.

Ultrasound-assisted acid/enzymatic hydrolysis preparation of loquat kernel porous starch: A carrier with efficient palladium loading capacity

Porous starch, with excellent renewal and thermodynamic stability characteristics, could be utilized as a novel carrier for metals. In this research, starch was obtained from wasted loquat kernel (LKS) and converted into loquat kernel porous starch (LKPS) through ultrasound-assisted acid/enzymatic hydrolysis. Then, LKS and LKPS were utilized for loading with palladium. The porous structures of LKPS were evaluated by the results of water/oil absorption rate and N2 adsorption analysis, and the physicochemical properties of LKPS and starch@Pd were analyzed by FT-IR, XRD, SEM-EDS, ICP-OES, and DSC-TAG. LKPS prepared by the synergistic method formed a better porous structure. Its specific surface area was 2.65 times that of LKS, and the water/oil absorption capabilities were considerably improved to 152.28 % and 129.59 %, respectively. XRD patterns showed that the presence of diffraction peaks at 39.7° and 47.1°, indicating successful palladium loading onto LKPS. The EDS and ICP-OES results revealed that the palladium loading capacity of LKPS was superior to that of LKS, with a significantly increased loading ratio of 2.08 %. In addition, LKPS@Pd exhibited excellent thermal stability, with a temperature range of 310-320 °C. Therefore, LKPS was a palladium carrier with highly efficient loading ratio, and LKPS@Pd had promising properties as a competent catalyst.

Tremella Polysaccharide Has Potential to Retard Wheat Starch Gel System Retrogradation and Mechanism Research

This study investigated the effects of adding different concentrations of TP (tremella polysaccharide) on the water distribution, rheological, thermal, microstructure, and retrogradation properties of WS (wheat starch) gels. The results showed that the starch aging increased during storage, and the addition of TP reduced the rate of change of the elastic modulus of the starch gel and delayed the short-term aging of WS. In the same storage period, the hardness value of the gel decreased and the texture became softer with the increase in the mass fraction of TP. TP increased the T0 (starting temperature) of the system and decreased the enthalpy of retrogradation (ΔHr). No new groups were formed after the retrogradation of the compound system, the hydrogen bonding force increased with the increase in polysaccharide, and the relative crystallinity and the degree of ordering of the system decreased. The addition of TP increased the content of bound water and immobile water, decreased the content of free water, and increased the gel water-holding capacity, indicating that it could effectively inhibit the long-term retrogradation of WS. The findings provide new theoretical insights for the production of starch-based foods.

Insights into the changes of structure and digestibility of microwave and heat moisture treated quinoa starch

In this study, quinoa starch was subjected to microwave and heat moisture treatment (MHT) with various moisture content (15 %, 25 %, 35 %) and microwave power (4.8, 9.6, 14.4 W/g), and its structure and digestibility were investigated. SEM and particle size analysis indicated that MHT caused the agglomeration of starch granules and increased the particle size. Moreover, MHT increased the short-range order structure and relative crystallinity, except for MHT with moisture content (35 %). DSC results demonstrated that the gelatinization temperature and gelatinization enthalpy had a slight improvement after MHT. Moreover, MHT increased the amylose content to some extent. It was worth noting that the digestibility of quinoa starch significantly decreased. After MHT, a part of rapidly digestible starch (RDS) was converted into slowly digestible starch (SDS) or resistant starch (RS). Particularly, when moisture content was 25 %, the starch had a highest SDS + RS content. Thus, this study provided a potential approach using MHT to modulate the digestibility of starch.

A Comprehensive Review of Pea (Pisum sativum L.): Chemical Composition, Processing, Health Benefits, and Food Applications

Pisum sativum L., commonly referred to as dry, green, or field pea, is one of the most common legumes that is popular and economically important. Due to its richness in a variety of nutritional and bioactive ingredients, the consumption of pea has been suggested to be associated with a wide range of health benefits, and there has been increasing focus on its potential as a functional food. However, there have been limited literature reviews concerning the bioactive compounds, health-promoting effects, and potential applications of pea up to now. This review, therefore, summarizes the literature from the last ten years regarding the chemical composition, physicochemical properties, processing, health benefits, and potential applications of pea. Whole peas are rich in macronutrients, including proteins, starches, dietary fiber, and non-starch polysaccharides. In addition, polyphenols, especially flavonoids and phenolic acids, are important bioactive ingredients that are mainly distributed in the pea coats. Anti-nutritional factors, such as phytic acid, lectin, and trypsin inhibitors, may hinder nutrient absorption. Whole pea seeds can be processed by different techniques such as drying, milling, soaking, and cooking to improve their functional properties. In addition, physicochemical and functional properties of pea starches and pea proteins can be improved by chemical, physical, enzymatic, and combined modification methods. Owing to the multiple bioactive ingredients in peas, the pea and its products exhibit various health benefits, such as antioxidant, anti-inflammatory, antimicrobial, anti-renal fibrosis, and regulation of metabolic syndrome effects. Peas have been processed into various products such as pea beverages, germinated pea products, pea flour-incorporated products, pea-based meat alternatives, and encapsulation and packing materials. Furthermore, recommendations are also provided on how to better utilize peas to promote their development as a sustainable and functional grain. Pea and its components can be further developed into more valuable and nutritious products.

The alterations in granule, shell, blocklets, and molecular structure of pea starch induced by ultrasound

Understanding the alterations to starch multi-scale structure induced by ultrasound treatment can help in determining the effective application of ultrasound in functional-starch preparation. This study aimed to comprehensively characterize and understand the morphological, shell, lamellae, and molecular structures of pea starch granules treated by ultrasound under different temperatures. Scanning electron microscopy and X-ray diffraction analyses showed that UT (ultrasound treatment) did not change C-type of crystalline, but caused a pitted surface and endowed a looser structure and higher enzyme susceptibility as the temperature increased above 35 °C for pea starch granules. Fourier transform infrared spectroscopy and small-angle X-ray scattering analyses revealed that UT reduced the short-range ordering and increased the thickness of semi-crystalline and amorphous lamellae by inducing starch chain depolymerization, which was manifested by molecule weight and chain length distribution analysis. The sample ultrasound-treated at 45 °C had the higher proportion of B2 chains compared with the other ultrasound-treated samples because the higher ultrasonic temperature altered the disruption sites of starch chains.

Increasing the pressure during high pressure homogenization regulates the starch digestion of the resulting pea starch-gallic acid complexes

The pea starch-gallic acid (PS-GA) complexes were prepared using high pressure homogenization (HPH), then the effect and underlying mechanism of pressure on multi-scale structure and digestibility of complexes were investigated. Results showed that HPH promoted the formation of PS-GA complexes, reaching the maximum complex index of 7.74 % at the pressure of 90 MPa, and the main driving force were hydrophobic interactions and hydrogen bonding. The interaction between PS and GA facilitated the formation of surface reticular structures to encapsulate gallic acid molecules, further entangled into bigger size aggregates. The enhancement of rearrangement and aggregation of starch chains during HPH developed a dense hierarchical structure of PS-GA complexes, including short-range ordered structure, V-type crystal structure, lamellar and fractal structure, thus increasing gelatinization temperature. The digestibility of PS-GA complexes substantially changed in reducing rapidly digestible starch content from 29.67 % to 17.07 %, increasing slowly digestible starch from 53.69 % to 56.25 % and resistant starch from 16.63 % to 26.67 %, respectively. Moreover, the resulting complexes exhibited slower digestion rates compared with native PS. Furthermore, the regulating mechanism of pressure during HPH on starch digestibility was the formation of ordered multi-scale structure and inhibition of GA on digestive enzymes.

Physicochemical properties and in vitro digestibility of highland barley starch with different extraction methods

The objective of this study was to compare the structural, thermal, rheological and digestive properties of highland barley starch (HBS) by different extraction methods. Five techniques were used to extract HBS: Alkali extraction, Ultrasound extraction, double enzyme extraction (DE), three enzyme extraction (TE) and ultrasonic assisted TE (U-TE). The results indicated that the Ultrasound extracted HBS had fewer Maltese crosses, lower molecular weight (Mw), and higher content of damaged starch (P < 0.05). Meanwhile, DE extracted HBS had higher Mw, and the content of short amylopectin than that of Alkali extracted HBS (P < 0.05). Additionally, the DE extracted HBS showed the highest relative crystallinity and good short-range ordered structure, which led to the outcome of stronger thermal stability and higher values of G' and G'' (P < 0.05). These results indicated that enzymatic extraction could better protect the resistance of HBS by protecting its physicochemical properties.

Analysis and Research on Starch Content and Its Processing, Structure and Quality of 12 Adzuki Bean Varieties

Investigating starch properties of different adzuki beans provides an important theoretical basis for its application. A comparative study was conducted to evaluate the starch content, processing, digestion, and structural quality of 12 adzuki bean varieties. The variation ranges of the 12 adzuki bean varieties with specific analyzed parameters, including the amylose/amylopectin (AM/AP) ratio, bean paste rate, water separation rate, solubility, swelling power and resistant starch (RS) content level, were 5.52-39.05%, 44.7-68.2%, 45.56-54.29%, 6.79-12.07%, 11.83-15.39%, and 2.02-14.634%, respectively. The crystallinity varied from 20.92 to 37.38%, belonging to type BC(The starch crystal type is mainly type C, supplemented by type B). In correlation analysis, red and blue represent positive and negative correlation, respectively. Correlation analysis indicated that the termination temperature of adzuki bean starch was positively correlated with AM/AP ratio. Therefore, the higher the melting temperature, the better the freeze-thaw stability. The 12 varieties were divided into Class I, Class II, and Class III by cluster analysis, based on application field. Class I was unsuitable for the diabetics' diet; Class II was suitable for a stabilizer; and Class III was suitable for bean paste, mixtures, and thickeners. The present study could provide a theoretical basis for their application in the nutritional and nutraceutical field.

Effects of Different Extraction Methods on the Gelatinization and Retrogradation Properties of Highland Barley Starch

The purpose of this study was to compare the gelatinization and retrogradation properties of highland barley starch (HBS) using different extraction methods. We obtained HBS by three methods, including alkali extraction (A-HBS), ultrasound extraction (U-HBS) and enzyme extraction (E-HBS). An investigation was carried out using a rapid viscosity analyzer (RVA), texture profile analysis (TPA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier-transform infrared spectrometry (FTIR). It is shown that the different extraction methods did not change the crystalline type of HBS. E-HBS had the lowest damaged starch content and highest relative crystallinity value (p < 0.05). Meanwhile, A-HBS had the highest peak viscosity, indicating the best water absorption (p < 0.05). Moreover, E-HBS had not only higher G′ and G″ values, but also the highest gel hardness value, reflecting its strong gel structure (p < 0.05). These results confirmed that E-HBS provided better pasting stability and rheological properties, while U-HBS provides benefits of reducing starch retrogradation.

Effect of Single and Dual Modifications on Properties of Lotus Rhizome Starch Modified by Microwave and γ-Irradiation: A Comparative Study

A comparative study between two novel starch modification technologies, i.e., microwave (MI) and γ-irradiation (IR), is of important significance for their applications. The objective of this work is to compare the changes in lotus rhizome starch (LRS) subjected to single modifications by MI (thermal treatment) and IR (non-thermal treatment), and dual modification by changing the treatment sequence, i.e., microwave followed by irradiation (MI-IR) and irradiation followed by microwave (IR-MI). The amylose content of native and modified LRS varied from 14.68 to 18.94%, the highest and lowest values found for native and MI-LRS, respectively. IR-treated LRS showed the lowest swelling power (4.13 g/g) but highest solubility (86.9%) among native and modified LRS. An increase in light transmittance value suggested a lower retrogradation rate for dual-modified starches, making them more suitable for food application at refrigeration and frozen temperatures. Dual-modified LRS showed the development of fissures and dents on the surface of granules as well as the reduction in peak intensities of OH and CH2 groups in FTIR spectra. Combined modifications (MI and IR) reduced values of pasting parameters and gelatinization properties compared to native and microwaved LRS and showed improved stability to shear thinning during cooking and thermal processing. The sequence of modification also affected the rheological properties; the G′ and G″ of MI-IR LRS were lower (357.41 Pa and 50.16 Pa, respectively) than the IR-MI sample (511.96 Pa and 70.09 Pa, respectively), giving it a soft gel texture. Nevertheless, dual modification of LRS by combining MI and IR made more significant changes in starch characteristics than single modifications.

Reactive Extrusion as a Pretreatment in Cassava (Manihot esculenta Crantz) and Pea (Pisum sativum L.) Starches to Improve Spinnability Properties for Obtaining Fibers

Starch is a biocompatible and economical biopolymer in which interest has been shown in obtaining electrospun fibers. This research reports that cassava (CEX) and pea (PEX) starches pretreated by means of reactive extrusion (REX) improved the starches rheological properties and the availability of amylose to obtain fibers. Solutions of CEX and PEX (30-36% w/v) in 38% v/v formic acid were prepared and the rheological properties and electrospinability were studied. The rheological values indicated that to obtain continuous fibers without beads, the entanglement concentration (Ce) must be 1.20 and 1.25 times the concentration of CEX and PEX, respectively. In CEX, a higher amylose content and lower viscosity were obtained than in PEX, which resulted in a greater range of concentrations (32-36% w/v) to obtain continuous fibers without beads with average diameters ranging from 316 ± 65 nm to 394 ± 102 nm. In PEX, continuous fibers without beads were obtained only at 34% w/v with an average diameter of 170 ± 49 nm. This study showed that starches (20-35% amylose) pretreated through REX exhibited electrospinning properties to obtain fibers, opening the opportunity to expand their use in food, environmental, biosensor, and biomedical applications, as vehicles for the administration of bioactive compounds.

Formation of Intermediate Amylose Rice Starch-Lipid Complex Assisted by Ultrasonication

Due to the potential reduction in starch availability, as well as the production of the distinct physico-chemical characteristics of starch in order to improve health benefits, the formation of starch–lipid complexes has attracted significant attention for improving the quantity of resistant starch (RS) content in starchy-based foods. The purpose of this research was to apply ultrasonication to produce intermediate amylose rice (Oryza sativa L.) cv. Noui Khuea (NK) starch–fatty acid (FA) complexes. The effects of ultrasonically synthesized conditions (ultrasonic time, ultrasonic amplitude, FA chain length) on the complexing index (CI) and in vitro digestibility of the starch–FA complex were highlighted. The optimum conditions were 7.5% butyric acid with 20% amplitude for 30 min, as indicated by a high CI and RS contents. The ultrasonically treated starch–butyric complex had the highest RS content of 80.78% with a V-type XRD pattern and an additional FTIR peak at 1709 cm⁻¹. The increase in the water/oil absorption capacity and swelling index were observed in the starch–lipid complex. The pasting viscosity and pasting/melting temperatures were lower than those of native starch, despite the fact that it had a distinct morphological structure with a high proportion of flaky and grooved forms. The complexes were capable of binding bile acid, scavenging the DPPH radical, and stimulating the bifidobacterial proliferation better than native starch, which differed depending on the FA inclusion. Therefore, developing a rice starch–lipid complex can be achieved via ultrasonication.

Modification of Pea Starch Digestibility through the Complexation with Gallic Acid via High-Pressure Homogenization

Pea starch and some legume starches are the side streams of plant-based protein production. Structural modification toward moderate digestibility and desirable functionality is a way to increase the economic values of these side-stream starches. We applied an innovative and sustainable technique, high-pressure homogenization, to alter pea starch structure, which resulted in a high level of complexation with the small phenolic acid molecule, gallic acid, to alter starch digestibility. This study showed a great level of disruption of the compact starch structure represented by the decrease in gelatinization temperature, enthalpy change, and relative crystallinity. The addition of a high concentration (10%) of gallic acid contributed to a typical V-type X-ray diffractometry pattern. Data demonstrated a significant decrease (~23%) in the susceptibility to α-amylase and an increase in resistant starch (~13%). In addition, starch functionality was improved with a reduced retrogradation rate. Pea starch responded to the high-pressure homogenization process well. Compared with the rice and maize starch reported in the literature, pea starch required a reduced amount of gallic acid to form a high level of complexation with a significant delay in starch digestion.

Comparison of physicochemical properties and digestibility of sweet potato starch after two modifications of microwave alone and microwave-assisted L-malic acid

The effects of microwave alone (MA) and microwave-assisted L-malic acid (MLA) on the physicochemical properties, structural and digestibility of sweet potato starch were investigated. The results showed that the swelling power, lightness (L^⁎) and whiteness index (WI), gelatinization enthalpy of starch decreased by MA and MLA treatment. The starch treated by MLA showed a new characteristic absorption peak at near 1735 cm^-1 in the measurement of FT-IR, while the starch treated with MA showed no new characteristic peak. The relative crystallinity of starch modified by MSE and MA decreased, but it still retained A-type crystal structure. Scanning electron microscopy showed that the surface destruction of MSE-modified starch was greater than that of starch modified by MA. MLA increased the content of resistant starch (RS), while MA reduced the content of resistant starch (RS). The relative crystallinity and gelatinization enthalpy of continuous 60 s treatment were lower than those of discontinuous 60 s treatment. These results indicated that MLA had a greater effect on the physicochemical properties, structural and digestibility of starch than MA. Starch modified by MLA can be added to foods as a low-carbohydrate ingredient, and the starch treated by MA is suitable for foods with low swelling, such as noodles.

Accumulation and physicochemical properties of starch in relation to eating quality in different parts of taro (Colocasia esculenta) corm

The accumulation and physicochemical properties of starch affect the eating quality of taro corm. This study aims to investigate the accumulation, morphology, and physicochemical properties of starch from inner and outer tissues in the top, middle, and basal parts of taro corm. Structural and morphological observations showed that the inner tissues of the taro corm accumulated more starch, and the middle tissue had moderate amylose content and the largest granule diameter. Starch from different tissues exhibited A-type orthorhombic structure and similar nuclear magnetic resonance spectrum. The relative crystallinity of starch in the middle tissue was higher than that in the top and basal tissues. Compared with middle and basal tissues, starch from top tissue showed higher peak viscosity, pasting time, swelling power and solubility. Compared with the top and basal tissues, the middle tissue of taro corm exhibited higher index of eating quality including smell, texture, and total evaluation score. The results indicated that starches in various spatial parts of taro corm exhibit differences in accumulation, morphology, structure and physicochemical properties that lead to diverse eating qualities.

Retaining a large amount of resistant starch in cooked potato through microwave heating after freeze-drying

Resistant starch (RS) is beneficial for humans, especially for the diabetes. Raw potato had a great deal of RS, while most of which become digestible after gelatinization. Thus, few RS will be retained in potatoes after regular cooking. To preserve RS in cooked potatoes as much as possible, microwave heating before (MFD) and after freeze-drying (FDM) were conducted with three different potatoes. After MFD, the RS content in potatoes was lower than 7% and the RDS content was higher than 45% for three potatoes. However, RS in potatoes treated with FDM was still as high as 40%, similar to that in the raw potatoes. Meantime, FDM caused less browning, produced a certain level of pyrazines, benzeneacetaldehyde and other flavor compounds, endowing cooked potatoes special baked flavor. Freeze-drying before microwave heating is a valuable way to reserve RS in cooked potatoes, which could also be used to reserve high RS content in crisp, chips, and other processed potatoes.

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Freeze-drying before microwave heating cause subtle effects on starch properties.

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Cooked potatoes by microwave heating after freeze-drying reserve rich RS.

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Microwave heating after freeze-drying caused less browning.

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Cooked potatoes by microwave heating after freeze-drying had special baking flavor.

Effect of inulin on pasting, thermal, rheological properties and in vitro digestibility of pea starch gel

The influence of inulin (IN) on pasting, thermal, rheological properties, and in vitro digestibility of pea starch gel was investigated. Results showed that as the concentration of IN in PS increased, the pasting temperature of PS gradually increased, while the value of peak viscosity, breakdown, and setback decreased. Rheological test suggested that all PS-IN gels were typical non-Newtonian fluids and exhibited a solid-like behavior. With the increased concentration of IN, hardness, chewiness, and gumminess of PS-IN gels significantly declined, in which the minimum value was at addition level of 20%. The presence of IN increased the gelatinization temperatures of PS-IN gels, while decreased the gelatinization enthalpy. Fourier-transform infrared spectroscopy (FT-IR) results indicated that no covalent bonding but intermolecular hydrogen bonding occurred between PS and IN. No influence of IN on the diffraction peak of PS after pasting was confirmed by X-ray diffraction analysis. In addition, IN decreased the content of rapidly and slowly digestible starch of PS, while increasing the content of resistant starch. These results will expand the application range of PS, and also provide a theoretical basis for the development of inulin-starch based products.

Effects of Auricularia auricula-judae polysaccharide on pasting, gelatinization, rheology, structural properties and in vitro digestibility of kidney bean starch

Auricularia auricula-judae polysaccharide (AP) has unique molecular structures and multiple bioactivities with excellent gel-forming property and thermal tolerance. However, few researches focus on the interactions between AP and legume starches. In this study, the effects of AP on the pasting, gelatinization, rheology, microstructure, and in vitro digestibility of kidney bean starch (KBST) were evaluated. The pasting, gelling and structural properties of AP-KBST mixtures were characterized by rapid visco analyzer, rheometry, texture analyzer, laser particle analyzer, low-field nuclear magnetic resonance, Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. And an in vitro method was employed to measure the digestibility of AP-KBST composites. The pasting viscosity, swelling degree of starch granules, viscoelasticity, gel strength, cold storage stability and water-retention capacity of KBST were enhanced with increasing AP concentration. The combination of AP and KBST exhibited a higher short-range ordered and a firmer and denser structure than that of KBST alone. Moreover, AP increased the contents of resistant starch and slowly digestible starch, which were positively correlated with the storage modulus and the degree of order, thereby suggesting that the formation of strong and ordered gel network structure by synergistic interactions between AP and KBST was responsible for the reduced starch digestibility.

Development of Absorbent Using Amylose-Graphite Composite Electrode for Removal of Heavy Metals

Amylose of Phragmites Australis captures heavy metals in a box consisting of sugar chains. However, its absorption rate is low in the period of the month scale. Therefore, the electrochemical driving force was used to promote the absorption rate in this research. Amylose was doped with TiO₂ porous graphite electrode. The composted absorbent was characterized using XRD(X-ray diffraction), SEM (Scanning Electrode Microscopy), Raman spectroscopy, and electrochemical methods. The affinity and maximum absorption amount were calculated using the isotherm method. In this study, Pb²⁺, Cu²⁺, Cd²⁺, and Cr⁶⁺ were chosen to demonstrate because these heavy metals are significant pollutants in Japan’s surface water. It was found that the maximum absorption was Cu²⁺ (56.82-mg/L) > Pb²⁺ (55.89-mg/L) > Cr⁶⁺ (53.97-mg/L) > Cd²⁺ (52.83.68-mg/L) at −0.5 V vs. Ag/AgCl. This is approximately the same order as the hydration radius of heavy metals. In other words, the absorption amounts were determined by the size of heavy metal ions. Subsequently, the mixed heavy metal standard solution was tested; the maximum absorption amount was 21.46 ± 10.03 mg/L. It was inferred that the electrochemical driving force could be shown as the ion size effect in the mixed solution. Despite there being no support for this hypothesis at this time, this study succeeded in showing that the electrochemical driving force can improve the ability of the absorbent.