Restricted Swelling Research Articles

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

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

MRI Evaluation of Traumatic and Non-traumatic Pathologies of the Ankle Joint and Hindfoot: A Single-Center Observational Study.

Background Pathologies affecting the ankle joint and hindfoot can present with a variety of clinical symptoms and etiologies, necessitating accurate diagnostic tools for effective management. Magnetic resonance imaging (MRI) is a valuable imaging modality for assessing these pathologies, providing detailed visualization of bone, joint, tendon, and other soft tissue abnormalities. Objectives To evaluate MRI findings in a diverse cohort of 105 participants with pathologies affecting the ankle joint and hindfoot, focusing on the prevalence and types of bone, joint, tendon, and soft tissue abnormalities. Materials and methods A single-center observational descriptive study was conducted at Dr. D. Y. Patil Medical College and Hospital and Research Centre, Pune, India, over a period from August 2022 to July 2024, involving 105 participants (54.3% male, 45.7% female) with a mean age of 39.04 years. MRI scans were analyzed to assess the prevalence of bone, joint, tendon, and soft tissue pathologies. Clinical profiles, symptom duration, and etiological classifications were documented. Results Analysis of the results obtained from 105 (N = 105) study participants revealed that pain (94.3%, or 99 cases) was the most common symptom, followed by restricted movement (86.7%, or 91 cases), trauma history (75.2%, or 79 cases), and swelling (73.3%, or 77 cases). Traumatic causes (76.2%, or 80 cases) predominated, while inflammatory (48.3%, or 14 cases) and infective (34.5%, or 10 cases) causes were also significant. MRI findings showed marrow edema in 41.9%, or 44 cases, subchondral cysts in 22.9% (24 cases), fractures in 17.1% (18 cases), and erosions in 10.5% of participants (11 cases). Joint involvement was most frequent in the tibiotalar (76.2%, or 80 cases) and subtalar joints (58.1%, or 61 cases). Tendon pathologies included peritendonitis (55.2%, or 58 cases) and tendinosis (23.8%, or 25 cases), with the Achilles tendon being the most frequently affected (39%, or 41 cases). Ligament injuries were predominantly sprains (46.7%, or 49 cases), with less frequent partial (18.1%, or 19 cases) and complete tears (7.6%, or eight cases). Soft tissue findings included subcutaneous edema (76.2%, or 80 cases) and bursitis (24.8%, or 26 cases). Among the study participants who presented with non-traumatic pathologies, inflammatory pathologies (48.3%, or 14 cases) were the most common, followed by infective (34.5%, or 10 cases) and neoplastic (17.2%, or five cases) pathologies. Conclusion MRI effectively identifies a wide range of pathologies in the ankle and hindfoot, with marrow edema, joint effusion, and tendon pathologies being prevalent. The study underscores the utility of MRI in diagnosing and assessing various conditions in the ankle joint complex and highlights the need for accurate imaging to guide treatment decisions. Future research should focus on correlating MRI findings with clinical outcomes to enhance diagnostic accuracy and management strategies.

Responsiveness of Charged Double Network Hydrogels to Ionic Environment

AbstractCharged double network (DN) hydrogels are widely studied for their desirable mechanical strength and tunable properties. In this work, the influence of polymer concentration on microstructure and properties of agarose/polyacrylic acid DN hydrogels is studied. Agarose, the first network, is a brittle biopolymer, while polyacrylic acid (PAAc) is a weak polyelectrolyte. The microstructure, visualized in liquid environment, displays an agarose scaffold coated and interconnected by PAAc, deviating from the common assumption of an entangled double network. Importantly, the charging of PAAc in the hydrogel is regulated not only by the pH and weak polyelectrolyte effects, but also by the restricted swelling of the double network, and hence, it is an inherent regulation mechanism of charged hydrogels. The interactions between the hydrogel and the ionic environment induce microstructural changes and charging of the double network, impacting surface properties such as topography, stiffness, and adhesion, which are spatially resolved by liquid‐environment atomic force microscopy. The responsiveness of the DN hydrogels significantly depends on both polymer concentrations and ion concentrations. These findings provide insights into the responsive behavior of double network hydrogels and reveal universal mechanisms for charged hydrogels, which can guide the future development of functional soft materials.

Hydrophobic and hygroscopic properties of cellulose treated with silicone agents

The effects of various cellulose treatments on the hydrophobic properties and sorption behavior with respect to liquid water uptake and water vapor sorption were examined within the study. Different hydrophobic agents based on silicon compounds were applied to improve the properties of cellulose-based sheets. The 1H,1H,2H,2H perfluorooctyltriethoxysilane treatment increased hydrophobicity significantly, while N-octyltriethoxysilane and inorganic sodium silicate solution treatments only slightly affected the properties. Silicone-cellulose interaction varied, influencing the fiber saturation and moisture content of the material. The swelling differences between untreated and treated cellulose and, consequently, the uncovering of new active sorption sites during a swelling process and the increase in the content of bound water were confirmed by the T2 relaxation times analysis. The GDW sorption model estimated maximum water content but lacked activation dynamics. The blocking phenomenon of active sorption sites together with silicone improved hydrophobicity had different mechanisms for applied agents. The 1H,1H,2H,2H perfluorooctyltriethoxysilane additionally cross-linked silane structure and restricted cellulose swelling.

Finite Element Modelling of the Effect of Adhesive Z-Connections on the Swelling of a Laminated Wood Composite

This study used finite element analysis (FEA) to model the effects of adhesive Z-connections on the thickness swelling of laminated wood composites exposed to water. We hypothesized that the area density, diameter, and spatial distribution of adhesive Z-connections will influence the ability of Z-connections to restrain thickness swelling of the composites. We tested this hypothesis by modelling a wood composite in ANSYS FEA software v. 17.0 to explore the effect of moisture on the thickness swelling of the wood composite. The results were compared with those obtained experimentally. We then examined the effect of the area density, size (diam.), and spatial distribution of the adhesive Z-connections on the thickness swelling of wood composites. Our results showed a positive correlation between the number of adhesive Z-connections in the composites and restriction of thickness swelling following 72 h of simulated moisture diffusion. Similarly, increasing the size of adhesive Z-connections also restricted thickness swelling. In contrast, different spatial distributions of Z-connections had little effect on restraining thickness swelling. Our modelling approach opens up opportunities for more complex designs of adhesive Z-connections, and also to examine the effect of wood properties, such as permeability, density, and hygroscopic swelling ratios on the thickness swelling of laminated wood composites.

Semi-interpenetrating network anion exchange membranes based on flexible polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene and rigid Poly(vinylbenzyl chloride) for fuel cell applications

Balancing ion conductivity, mechanical strength, and alkali stability is a significant challenge in the application of anion exchange membranes (AEMs) in anion exchange membrane fuel cells (AEMFCs). In this study, rigid poly(4-vinylbiphenyl chloride) (PVB) and flexible polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) are selected as the polymer backbones to create semi-interpenetrating network (SIPN) AEMs. To achieve high ionic conductivity, quaternary ammonium groups are grafted onto each PVB structural unit, and TMHDA reacts with CMSEBS to construct a cross-linking network while also generating quaternary ammonium groups. This approach, along with well-defined micro-morphology, result in SIPN-SEBS/PVB-10 exhibiting an impressive ionic conductivity of 105.7 mS cm−1 at 80 °C. The SIPN structure, formed by the linear quaternary ammonium PVB and cross-linked SEBS, enhances the compatibility between the rigid and flexible components, resulting in good tensile strength (>14.5 Mpa) and elongation at break (>31.8%) for SIPN-SEBS/PVB AEMs at 25 °C in the wet state. Furthermore, SIPN-SEBS/PVB AEMs exhibit excellent chemical stability, in addition to the restricted swelling behavior, which can be attributed to the stable PVB and SEBS main chains. After immersion in a 1 M NaOH solution at 80 °C for 30 days, the degradation of backbones and cations in all membranes is less than 10% and 20%, respectively. Moreover, the peak power density of SIPN-SEBS/PVB-10 in an H2/O2 single fuel cell reaches an impressive value of 379 mW cm−2. Based on these excellent properties, the developed SIPN AEMs hold great promise as candidates for AEMFCs.

Isolation and Characterization of Colon Targeting Starch from the Non‐Conventional Source of Jharkhand, India

AbstractStaple foods are generally the conventional sources of starch. The exploration of non‐conventional and cheap sources of starch has gained momentum. In the present study, starch from mankanda (Alocaisa macrrorhizos) tubers is isolated by using base, NaOH 0.05%, w/w sodium hydroxide extracted starch (NAS) and acidic (citric acid 0.03%; Citric acid extracted starch (CAS) media and evaluated for its physicochemical, structural, thermal, rheological, and release profile. The %yield of NAS and CAS starch is found to be 8.14% and 7.28%, with neutral pH, high water holding capacity, moisture content, amylose content, low ash values, restricted swelling, and excellent flow. The granules of the starches are irregular, with a diameter ranging from 1.34 to 16.12 µm. X‐ray diffraction (XRD) analysis reveals the combination of type A and B crystal. Fourier Transform Infrared Spectroscopy (FT‐IR) spectra of both starch samples are almost found to be similar in nature. Thermogravimetric analysis (TGA) and differential scanning colorimetric (DSC) analysis indicate good thermal stability. Both starches exhibit shear thinning behavior. In vitro drug release studies reflect that the extracted native starch from mankanda tubers has an immense potential for the development of sustained release formulations to target the lower gastrointestinal region like the colon by protecting the drug from the physiological environment of the stomach and small intestine.

Immobilized hindered amine radical scavenger for durability enhancement of perfluorosulfonic acid membrane in PEMFCs

Membrane durability is one of the crucial considerations that restrict the development of proton exchange membrane fuel cells (PEMFCs). The widely used and inexpensive stabilizer hindered amine 4-amino-2,2,6,6-tetramethylpiperidine (TEMP) was selected as the free radical scavenger and tethered onto the skeleton of carboxyl-functionalized metal-organic frameworks for addressing its migration problem. The resulted inorganic-organic hybrid dopant (UIO-66-TEMP) was then incorporated into the Nafion matrix to alleviate the attacks of free radicals on the membrane in the fuel cell working circumstances. Besides the improved mechanical strength and oxidative stability, and restricted water swelling and hydrogen crossover, the resulted hybrid membranes also possess excellent proton conductivity up to 176 mS cm−1, endowing them with high power density up to 612.78 mW cm−2, 1.5 times higher than recast Nafion. After accelerated durability testing for 120 h, the OCV decay rate of the hybrid membranes decreased to 0.74 mV h−1, only 40% of recast Nafion (1.89 mV h−1). Meanwhile, the optimized hybrid membrane still maintained a high peak power density of 463.62 mW cm−2 and a low hydrogen crossover density of 4.44 mA cm−2, which were superior to recast Nafion after OCV durability tests. Hindered amines can be “regenerated” by the “Denisov cycle” to ensure that they can be used sustainably in the fuel cell. The results demonstrate that the novel UIO-66-TEMP decorated with hindered amine radical scavengers are promising nanofillers for mitigating the membrane degradation and improving the proton conductivity, thereby significantly enhancing the performance and durability of PEMFCs.

High amylose starch thermally processed by ohmic heating: Electrical, thermal, and microstructural characterization

High amylose starch (HAS) exhibits restricted granular swelling, limiting its use in many food applications. In this work, we investigated for the first time the potential of ohmic heating (OH) to enhance the swelling of HAS granules in a very efficient manner in terms of processing times. Specifically, the impact of OH at two voltages (130 and 150 V), two moisture conditions (1:3 and 1:5 w/v), and two final temperatures (160 and 180 °C) on the structural, thermal, pasting, and digestion of HAS (70% amylose, AM) was investigated. The electrical conductivity of native HAS showed a transition at 168 ± 1 °C consistent with the thermal transition at 139–192 °C (DSC) with an enthalpy of 11.39 J/g. Furthermore, OH caused a reduction of resistant starch (RS) from 52.0 to 34.5%, and a significant increase in granular swelling (as represented by the increased initial, maximum, and final viscosities). The above was further corroborated by SEM micrographs, which showed the disruption of the granular structure that aligned with a decrease in the relative crystallinity and shift to a B-type polymorphism. Results showed that the high temperatures reached during ohmic heating result in partial HAS gelatinization and enhanced granular swelling.

Core-shell starch as a platform for reducing starch digestion and saturated fat intake

Ill-balanced diets, especially high-carbohydrate and high-fat diets, have led to an explosion of diabetes and cardiovascular diseases worldwide, posing great threats to human health. The structural design of functional foods can offer promising solutions to these afflictions. Here, we introduce a versatile core-shell starch made from food-grade starch and alcohol-soluble protein to reduce starch digestion and saturated fat intake. The fabrication of core-shell structure is realized through an anti-solvent method, assisted by electrostatic interaction, which is generalizable to starches and proteins from different sources and feasible for scale-up production. The protein shell imparts a higher gelatinization temperature and a lower pasting viscosity to the starch, suggesting restricted granule swelling, which leads to a reduced starch digestibility as proved by in vitro digestion studies. The hypoglycemic effect of core-shell starch is demonstrated in vivo. We also show that the application of core-shell starch can be extended to oil encapsulants and saturated fat replacers due to the impact of protein shell on the surface hydrophobicity of the starch. These results may advance the establishment of healthy diets and the tackling of diet-related diseases.

Differences in characteristics and infection severity between odontogenic and other bacterial oro-naso-pharyngeal infections

BackgroundDifferent bacterial infections of the oro-naso-pharyngeal (ONP) region may progress and require hospital care. The present study clarified differences in infection characteristics between hospitalized patients with odontogenic infections (OIs) and other bacterial ONP infections. The specific aim was to evaluate clinical infection variables and infection severity according to infection aetiology, particularly regarding features of OIs compared with other ONPs.MethodsRecords of patients aged ≥16 years requiring hospital care for an acute bacterial ONP infection in the emergency units of Otorhinolaryngology or Oral and Maxillofacial Surgery at the Helsinki University Hospital (Helsinki, Finland) during 2019 were evaluated retrospectively. The main outcome variables were need for intensive care unit (ICU) treatment and length of hospital stay. The primary predictor variable was infection category, defined as OI or other ONP. The secondary predictor variable was specific ONP infection group. Additional predictor variables were primary clinical infection signs, infection parameters at hospital admission, and delay from beginning of symptoms to hospitalization. Explanatory variables were sex, age, current smoking, heavy alcohol use or substance abuse, and immunosuppressive disease, immunosuppressive medication, or both. Comparison of study groups was performed using Fisher’s exact test, student’s t-test, and Mann-Whitney U.ResultsA total of 415 patients with bacterial ONPs fulfilled the inclusion criteria. The most common infections were oropharyngeal (including peritonsillar, tonsillar, and parapharyngeal infections; 51%) followed by infections from the odontogenic origin (24%). Clinical features of OIs differed from other ONPs. Restricted mouth opening, skin redness, or facial or neck swelling (or both) were found significantly more often in OIs (p < 0.001). OIs required ICU care significantly more often than other ONPs (p < 0.001) and their hospital stay was longer (p = 0.017).ConclusionsInfections originating from the tonsillary and dental origin had the greatest need for hospitalization. Clinical features of OIs differed; the need for ICU treatment was more common and hospital stay was longer compared with other ONPs. Preventive care should be emphasized regarding OIs, and typical infection characteristics of ONP infection subgroups should be highlighted to achieve early and prompt diagnosis and treatment and to reduce hospitalization time.

Exploring the underlying mechanisms on starch restricted swelling-induced reduction in digestion rate of buckwheat noodles

To elucidate the slower digestion rate of buckwheat starch in noodles-matrix, the digestion kinetics of Tartary (TBN) and common (CBN) buckwheat starch reconstituted noodles as well as wheat starch reconstituted noodles (WSN) were compared using a simulated oral-gastric-intestinal in vitro digestion. The swelling degree of starch in cooked noodles can be expressed by quantitative analysis of microstructure. The digestion rate of WSN was 2.3–2.9 times higher as compared to CBN and TBN. The swelling degree of starch in CBN and TBN was restricted due to their denser structure, which led to the reduction of the contact area between starch molecules and amylase. Additionally, the stronger water retention ability and higher cohesiveness of CBN and TBN could hinder the water migration, and ultimately affect the accessibility of enzymes. These results demonstrated that the restricted swelling of starch in CBN and TBN during cooking was the important reason for their slower digestibility.

White Latex: Appealing "Green" Alternative for PVdF in Electrode Manufacturing for Sustainable Li-Ion Batteries.

Nowadays, poly(vinylidene fluoride) (PVdF) has been dominantly utilized as a polymeric binder in commercialized Li-ion batteries. However, standardized PVdF-based electrode manufacturing seems cost-intensive and environmentally hazardous, which relies on the usage of toxic N-methyl-2-pyrrolidone (NMP) as a dispersant. In view of cost control and environmental awareness, switching to a water-processable green binder, as a substitute for PVdF, has been imperative with realistic significance. Herein, commercially available white latex (WL), containing poly(vinyl acetate) as a staple ingredient, was directly used as an alternative aqueous binder for PVdF in the fabrication of graphite/Li4Ti5O12-based lithium-ion anodes. WL exhibits robust adhesion of the electrode coating to the current collector; meanwhile, the restricted electrolyte swelling of the binder is verified by in situ electrochemical dilatometry. Outperforming PVdF, WL endows graphite with extensive surface coverage by the binding agent, dramatically reducing irreversible decomposition of the electrolyte (SEI formation) on graphite. Consequently, the WL-based graphite anode delivers the highest initial coulombic efficiency (CE) of 92% and remarkable long cyclic stability with a high capacity retention of 332.7 mAh/g, compared to the PVdF- and carboxymethyl cellulose (CMC)-based ones. Moreover, WL is also compatible with Li4Ti5O12, endowing it with more stable cycling behavior than that of the counterparts prepared with both PVdF and even CMC. Our described WL represents an appealing "green" alternative for PVdF in manufacturing sustainable and ecofriendly energy storage devices.

Effects of oil-modified crosslinked/acetylated starches on silver carp surimi gel: Texture properties, water mobility, microstructure, and related mechanisms

This study investigated the texture properties, water mobility and microstructure of surimi gel added with crosslinked tapioca starch (CTS) and acetylated tapioca starch (ATS), and their counterparts modified with oil (Oil-CTS and Oil-ATS, respectively). Both Oil-CTS and Oil-ATS could improve the breaking force, deformation and elasticity of surimi gel, especially Oil-CTS. Additionally, oil-modified starches could increase the water-holding capacity of surimi gels and prompt the transformation of free water to bound water, resulting in the decrease of water mobility. The difference between oil-modified starches and their counterparts in gel-enhancing effect is due to the swelling ability and different microstructure of surimi/starch gels. Namely, oil-modified starches prompted the formation of a more homogeneous and compact gel network, endowing the surimi/Oil-CTS gel with tiny pores due to its restricted swelling property, while others were opposite. Raman spectral results further unveiled that the addition of oil-modified starches promoted the protein conformational transition from α-helix to β-sheet and β-turn, as well as a decrease of ionic bonds and an increase of hydrogen bonds and hydrophobic interactions of surimi gel, which were beneficial to form firm and compact gel structure. The overall results indicated the new oil-modified starches (especially Oil-CTS) have great potential to improve the quality of surimi-based products.

Tuning interlayer structure to construct steady dual-crosslinked graphene oxide membranes for desalination of hypersaline brine via pervaporation

Graphene oxide (GO) membranes have shown great potential in desalination. However, it is still a challenge to tune the interlayer structure of GO and suppress its swelling in water to realize superior separation performance and enhance the mechanical stability of membrane. Herein, polyethyleneimine (PEI) with different molecular weight was employed to crosslink GO nanosheets and tune interlayer spacing of lamellar GO membrane for desalination of hypersaline brine by pervaporation (PV). A dual crosslinking structure was performed via electrostatic interaction and covalent bonding between PEI and GO rendering effectively restricted swelling of GO. The interlayer spacing was adjusted by tuning PEI molecular weight and the surface charge of GO membrane was converted to positive to repel ions. The membrane crosslinked with larger PEI (c-GO-PEI 70k) exhibited the most robust structure and showed outstanding PV desalination performance with high water flux of 86.0 kg/m2 h and salt rejection of 99.99% in treating 10 wt% NaCl hypersaline solution at 90 °C. This work provides further understanding of regulating interlayer structure and constructing high-performance GO membranes for PV desalination.

Effect of degree of cross linking on physicochemical, rheological and morphological properties of Sorghum starch

Sorghum starch was cross-linked (CL) with epiclorohydrin (EPI) at different concentrations (0.1–1.0%). Degree of cross-linking (DC) ranged between 49.5-89.7% (for 0.5–1.0% CL starch); the highest value was observed for 1.0% CL starch. Amylose content, swelling power, and solubility ranged between 5.1–18.5%, 6.9–10.5 g/g, 6–11%, respectively. As compared to native starch, peak viscosity increased for 0.1 and 0.3% CL starches, further increase in cross-linking levels resulted in decrease. Temperature sweep testing showed lower G′ values for 0.3–1.0% CL starches in comparison to native starch. Frequency sweep testing of CL starches showed G′ and G′′ values between 365–2010 Pa and 67–113 Pa, respectively.The flow behaviour index (n) ranged between 0.14–0.34, indicating shear thinning behaviour of CL starch pastes. Consistency index (K) value varied from 20.23–119.2 (Pa.s), the highest and the lowest values were observed for 0.1 and 1.0% CL starches, respectively. Crosslinking resulted in pronounced effect on starch morphology. CL starches showed rough surface, cavities and cracks on their surface. For stabilized granular structure and restricted swelling, CL starch is most commonly used in food industry.

Mechanical properties of starch-filled alginate gel particles

The aim of this work was to investigate the mechanical behaviour of alginate-based composite particles. Alginate gel beads with entrapped starch were used as the replicates of storage cells of plant tissue. Beads were formulated using different ratios of both ingredients and were produced using two methods, resulting in particles in the macro- and micro-scale size range. Compression tests revealed an effect of bead size on mechanical properties and a dominant role of the alginate on the material properties. Starch was successfully encapsulated as native granules in the beads and once encompassed, it suffered restricted swelling, up to 45 % of its original size, after undergoing heating. Force versus displacement data were fitted to both an empirical and the Hertz model and Young’s modulus was found to increase only with heated starch inclusions. Microscopy was deemed crucial for the interpretation of mechanical measurements.

Properties of extruded cross-linked waxy maize starches and their effects on extruded oat flour

The objectives of this study were to study the extrusion of cross-linked waxy maize starches (CLWMS) with different cross-linking levels and their function as a secondary ingredient in extruded oat flour (OF) formulations. CLWMS (18 %) and OF (82 %) were hydrated to 20 % moisture content and subjected to twin-screw extrusion at the screw speed of 350 rpm. Low cross-linking level of CLWMS (0.05 % sodium trimetaphosphate/sodium tripolyphosphate) in OF formulation increased the void fraction and reduced the breaking strength of extrudates. The low cross-linked starch was more resistant to breakdown and had a higher pasting viscosity than the unmodified starch. Higher cross-linking levels of CLWMS restricted swelling of starch granule and increased the resistant starch level of OF formulation but had very poor structural and textural properties. Varying the level of cross-linking offers an alternative way to manipulate the structural, textural and nutritional properties of extrudates in snack and cereal applications.

Intact endosperm cells in buckwheat flour limit starch gelatinization and digestibility in vitro.

The objective of this study was to determine the biophysical properties of buckwheat (BW) endosperm and their influences on detachment of intact cells, starch gelatinization and digestibility. The intact cells were isolated from BW kernels by dry milling and sieving. The microscopy and texture analysis showed intact endosperm cells could be detached easily due to the fragile structure and low hardness of BW endosperm. More than 70% intact cells were found in commercial light flour. The starch granules entrapped in intact cells exhibited a delay gelatinization and restricted swelling behavior (2-3℃ higher onset gelatinization temperature than isolated starch). Starch in BW flour had a markedly lower extent of digestion compared to the broken cells and isolated starch. This study provided a new mechanistic understanding of low glycemic index of BW food, and could guide the processing of BW flour to retain slow digestion properties.

Observations on the impact of amylopectin and amylose structure on the swelling of starch granules

Four different types of amylopectin structure have been reported in our earlier work based on the internal unit chain profile obtained from limit dextrins of amylopectin and data strongly suggested that chain length and organization of internal unit chains of amylopectin influence the gelatinization and retrogradation properties of the starch. Another important functional attribute is granule swelling that mainly contributes to the viscosifying property of starches. In this study, unmodified defatted amylose-containing starch granules possessing amylopectin of four types were subjected to swelling in warm water. The swelling pattern of the granules was related to the structural type of the amylopectin component. Granules having amylopectin of Type 1 structure started to swell at lower temperature (about 55 °C) and possessed more restricted swelling than most of the other starches. Type 1 starches lost their integrity at temperatures above 85 °C, whereas starch granules with Type 2 and 3 amylopectin were still intact at 95 °C. Starches with Type 4 amylopectin were heterogeneous with respect to their swelling: Lesser yam starch possessed comparatively restricted swelling between 75 and 95 °C, whereas canna and potato starch swelled extensively and disintegrated already before 95 °C. Some waxy samples were also included in the investigation and these were generally more sensitive to swelling than their non-waxy counterparts, showing that amylose restricts the swelling and stabilizes the granular structure, albeit there was no correlation between the apparent amylose content and the swelling of tested samples. Instead, the result suggested a correlation between the structure of amylopectin and the deposition of amylose in the starch granules.