Effect of high hydrostatic pressure on the supramolecular structure of corn starch with different amylose contents

Effect of ethanol addition on the physicochemical, structural and in vitro digestive properties of Tartary buckwheat starch-quercetin/rutin complexes

The effects of ethanol on the physicochemical, structural and in vitro digestive properties of Tartary buckwheat starch-quercetin/rutin complexes (e-TBSQ and e-TBSR) were investigated. Ethanol restricted the gelatinization of Tartary buckwheat starch (TBS), which resulted an increase in ∆H, G' and G" as well as a decrease in apparent viscosity of e-TBSQ and e-TBSR. The particle size, scanning electron microscopy and X-ray diffraction results showed that ethanol influenced the morphological structure of TBS granules and the starch crystalline structure in e-TBSQ and e-TBSR changed from B-type to V-type when the ethanol concentration was 25%. Saturation transfer difference-nuclear magnetic resonance results revealed that ethanol weakened the binding ability of quercetin/rutin to TBS in e-TBSQ and e-TBSR, leading to a change in the binding site on the quercetin structural unit. The residual ungelatinized TBS granules in e-TBSQ and e-TBSR induced a high slowly digestible starch content, and thus displayed a "resistant-to-digestion".

Lecithin enhances the complexation between pea starch and fatty acids in aqueous system, and affects the starch's structure and enzymatic hydrolysis

This paper investigates a newly found effect of lecithin on the complexation between starch and saturated fatty acids. Rapid visco analysis showed that adding lecithin to the pea starch-fatty acid mixtures resulted in a viscosity peak during the setback stage of the pasting curve. Subsequent differential scanning calorimetry showed that pea starch-fatty acid-lecithin systems formed more V-type structures than pea starch-fatty acid complexes. X-ray diffraction and Fourier transform infrared spectroscopy indicated the addition of lecithin developed the long-range and short-range order of the V-complexes. Small-angle X-ray scattering showed the ternary system had a more compact stack in nano-scale and smaller D bragg than the binary complex. In vitro enzymatic hydrolysis revealed higher hydrolysis resistance of ternary systems compared to binary complexes. The results of this research provide a mechanism for modifying starch-lipid complexes and contribute to scientific understanding of food ingredient interactions.

The Application of High-Hydrostatic-Pressure Processing to Improve the Quality of Baked Products: A Review

The current trend in the food industry is towards "clean label" products with high sensory and nutritional quality. However, the inclusion of nutrient-rich ingredients in recipes often leads to sensory deficiencies in baked goods. To meet these requirements, physically modified flours are receiving more and more attention from bakery product developers. There are various findings in the literature on high hydrostatic pressure (HHP) technology, which can be used to modify various matrices so that they can be used as ingredients in the baking industry. HHP treatments can change the functionality of starches and proteins due to cold gelatinization and protein unfolding. As a result, the resulting ingredients are more suitable for nutrient-rich bakery formulations. This review describes the information available in the literature on HHP treatment conditions for ingredients used in the production of bakery products and analyses the changes in the techno-functional properties of these matrices, in particular their ability to act as structuring agents. The impact of HHP-treated ingredients on the quality of dough and bakery products and the effects on some nutritional properties of the treated matrices have been also analysed. The findings presented in this paper could be of particular interest to the bakery industry as they could be very useful in promoting the industrial application of HHP technology.

The effects of high-pressure treatment on the structure, physicochemical properties and digestive property of starch - A review

High hydrostatic pressure (HHP) is a novel technology used in the food-processing industry. Starch is an important renewable natural resource. The applications of starch are determined by its properties, which in turn are determined by its structure. In this study, the effects of HHP treatment on starch structure (granular structure, crystalline structure, molecular structure, and molecular conformation) and properties (pasting, retrogradation, thermal, digestive, rheological, swelling, solubility, water absorption, and oil absorption properties) are summarised. Additionally, the mechanism of HHP-induced gelatinisation is discussed. First, the strong hydration ability of starch molecules under high pressure facilitates the binding of water molecules to starch molecules via hydrogen bonding. These bound water molecules may block the channels inside the starch granules, leading to the formation of a sealed space. Finally, the granules disintegrate because of the intra/extra pressure difference. This study provides a reference for the application of HHP to starch processing and modification.

Microstructures of Starch Granules with Different Amylose Contents and Allomorphs as Revealed by Scattering Techniques

In this study, as-is (ca. 12% moisture by mass) and hydrated (50% water by mass) granules of waxy potato (WP), waxy wheat (WW), waxy maize, normal maize, and high-amylose maize (HAM) starches were investigated by using small-angle neutron and X-ray scattering (SANS and SAXS), wide-angle X-ray scattering, and ultra-small-angle neutron scattering. The SANS and SAXS data were fitted using the two-phase stacking model of alternating crystalline and amorphous layers. The partial crystalline lamellar structures inside the growth rings of granules were analyzed based on the inter-lamellar distances, thicknesses of the crystalline lamellae and amorphous layers, thickness polydispersities, and water content in each type of layer. Despite having a longer average chain length of amylopectin, the WP and HAM starches, which had B-type allomorph, had a shorter inter-lamellar distance than the other three starches with A-type allomorph. The WP starch had the most uniform crystalline lamellar thickness. After hydration, the amorphous layers were expanded, resulting in an increase of inter-layer distance. The low-angle intensity upturn in SANS and SAXS was attributed to scattering from interfaces/surfaces of larger structures, such as growth rings and macroscopic granule surfaces. Data analysis methods based on model fitting and 1D correlation function were compared. The study emphasized─owing to inherent packing disorder inside granules─that a comprehensive analysis of different parameters was essential in correlating the microstructures with starch properties.

Effects of the Amylose/Amylopectin Content and Storage Conditions on Corn Starch Hydrogels Produced by High-Pressure Processing (HPP)

In this study, the effects of the amylose/amylopectin content on starch gelation and the physical characteristics of hydrogels produced by HPP were studied by optical and rheological measurements in steady-state conditions. Additionally, the effects of the storage temperature (4 °C and 20 °C) and type of packaging (plastic bags or sealed Petri dishes) on the physical stability of the hydrogels were evaluated for 30 days of storage by evaluating the shrinkage of the granules, as well as the weight loss, water activity, organoleptic, and rheological properties. The experimental findings suggested that amylose plays an antagonistic role in determining the capacity of the starch granules to absorb water under pressure and to create stable and structured gels and on the physical stability of hydrogels due to its influence over the starch retrogradation extent during storage. Twenty per cent amylose was the minimum concentration to form stable corn starch HPP hydrogels with good physical and rheological properties. Moreover, a storage temperature of 20 °C and the use of polymeric bags were evaluated as the most suitable storage conditions and packaging materials enabling the long storage of corn starch hydrogels.

Recent advances in structural characterization of biomacromolecules in foods via small-angle X-ray scattering

Small-angle X-ray scattering (SAXS) is a method for examining the solution structure, oligomeric state, conformational changes, and flexibility of biomacromolecules at a scale ranging from a few Angstroms to hundreds of nanometers. Wide time scales ranging from real time (milliseconds) to minutes can be also covered by SAXS. With many advantages, SAXS has been extensively used, it is widely used in the structural characterization of biomacromolecules in food science and technology. However, the application of SAXS in charactering the structure of food biomacromolecules has not been reviewed so far. In the current review, the principle, theoretical calculations and modeling programs are summarized, technical advances in the experimental setups and corresponding applications of in situ capabilities: combination of chromatography, time-resolved, temperature, pressure, flow-through are elaborated. Recent applications of SAXS for monitoring structural properties of biomacromolecules in food including protein, carbohydrate and lipid are also highlighted, and limitations and prospects for developing SAXS based on facility upgraded and artificial intelligence to study the structural properties of biomacromolecules are finally discussed. Future research should focus on extending machine time, simplifying SAXS data treatment, optimizing modeling methods in order to achieve an integrated structural biology based on SAXS as a practical tool for investigating the structure-function relationship of biomacromolecules in food industry.

Supramolecular structure of quinoa starch affected by nonenyl succinic anhydride (NSA) substitution

Quinoa starch granular structure as affected by nonenyl succinic anhydride (NSA) substitution was investigated by multiple approaches, including scattering, spectroscopic, and microscopic techniques. The modification had little impact on the morphology of starch granules. The NSA substitution was found mainly in the amorphous lamellae and amorphous growth rings. The NSA modification increased the thickness of the amorphous lamellae. The homogeneity of the ordered structure in the granules was improved, probably because the NSA modification reduced the amount of defects in the semi-crystalline growth ring. Compared to other chemical modifications such as acylation, succinylation was more effective in modifying the starch lamellar structure. A possible reaction pattern of NSA modification on quinoa starch is proposed, in which the NSA modification may follow the sequence of amorphous growth rings, the amorphous matrices among blocklets, amorphous and crystalline lamellae in semi-crystalline growth rings. This study provides new insights on the structural changes of starch granules induced by succinylation on the supramolecular level.

Improvement of buckwheat noodles quality via differential pressure explosion puffing (DPEP): cooking and structural quality

In order to improve the poor formability and taste, a method of buckwheat noodles via differential pressure explosion puffing (DPEP) pre-gelatinization was developed. The effects of DPEP on gelatinization properties of buckwheat flour was investigated. The textural properties, sensory evaluation, cross section morphology, crystal structure, thermodynamic properties and simulated digestion in vitro of buckwheat noodles were characterized. The results indicated that DPEP treatment was beneficial for the texture properties and sensory evaluation, while the cooking loss rate and broken rate of noodles were reduced to 16.31% and 6.28%. The crystal structure of starch in noodles pretreated via DPEP form a more compact structure and enhanced the water holding capacity. DPEP reduced the digestibility in vitro of the noodles. The level of rapidly digestible starch reduced to 15.6%, slowly digestible starch and resistant starch increased to 21.6% and 62.8%, which made the buckwheat noodles have potential to improve health of diabetics.

Nonthermal physical modification of starch: An overview of recent research into structure and property alterations

To tailor the properties and enhance the applicability of starch, various ways of starch modification have been practiced. Among them, physical modification methods (micronization, nonthermal plasma, high-pressure, ultrasonication, pulsed electric field, and γ-irradiation) are highly potential for starch modification considering its safety, environmentally friendliness, and cost-effectiveness, without generating chemical wastes. Thus, this article provides an overview of the recent advances in nonthermal physical modification of starch and summarizes the resulting changes in the multi-level structures and physicochemical properties. While the effect of these techniques highly depends on starch type and treatment condition, they generally lead to the destruction of starch granules, the degradation of molecules, decreases in crystallinity, gelatinization temperatures, and viscosity, increases in solubility and swelling power, and an increase or decrease in digestibility, to different extents. The advantages and shortcomings of these techniques in starch processing are compared, and the knowledge gap in this area is commented on.

Effect of cooling rate on long-term recrystallized crystal of rice starch in the presence of flavor compounds

This study evaluated the effect of cooling rate on starch recrystallization in the presence of 2,3-butanedione and 2-acetyl-1-pyrroline, which could form B-type and V-type complexes with starch, respectively. Rapid cooling resulted in poor perfection and high heterogeneity of both B-type and V-type recrystallized crystal. For B-type crystal, rapid cooling changed nucleation mode from instantaneous (Avrami index n < 1) to continuous mechanism (1 ≤ n ≤ 2), and decreased recrystallization rate from 0.0502 to 0.0160 d^-n, indicating the increased retention of starch on 2,3-butanedione. V-type crystal was formed at initial stages of recrystallization, and inhibited the growth of B-type crystal. The loose crystalline obtained by rapid cooling is conducive to the retention of flavor compounds for B-type complexes (especially ≤14 days) and V-type complexes (especially ≤1 day). These results could provide guidance for maintaining fragrance of instant rice during long-term storage.

Storage temperature and time affect the enzyme resistance starch and glycemic response of cooked noodles

White-salted noodles are prepared, stored and consumed in various ways. However, relationships among cooking and storage conditions on nutritional functionality are not fully understood. The manuscript elucidates the mechanism of formation of resistant starch (RS) leading to slower digestion rate of variously cooked (boiled, steamed, stir-fried, fried and microwave heated) noodles followed by storage under different conditions (-18, 4 and 25 °C for 4, 24 and 48 h). RS content of noodles stored at 25 °C was higher than noodles stored at 4 °C, which was consistent with increases in the degree of crystallinity during storage. We showed that the residual moisture content primarily facilitated the mobility of starch chains and contributed towards the increase in RS associated with the decrease of enzyme susceptivity of noodles after storage. Evidence that supramolecular organization (helical structure and crystallinity) had a more pronounced effect than the macroscopic structure such as compactness or bulk density was also provided.

The analysis of the effects of high hydrostatic pressure (HHP) on amylose molecular conformation at atomic level based on molecular dynamics simulation

For more effective using of HHP (high hydrostatic pressure) in starch processing, in this study, molecular dynamics simulation was used to explore the effects of pressure on amylose molecular conformation at the atomic level. The results shown that, firstly, high pressure decreased the intramolecular hydrogen bonds and increased the amylose-solvent hydrogen bonds, which is consistent with the process of high pressure starch gelatinization. Secondly, high pressure made amylose polymers more "stout". Meanwhile, high pressure decreased the angle of α-1,4 glycosidic linkage and increased the dihedral angles of α-1,4 glycosidic linkage, which indicates that pressure has obvious effects on amylose molecular conformation. Thirdly, high pressure made amylose polymers more stable. Moreover, in view of the results of energies, HHP may have an opposite gelatinization mechanism to heating. The results may be complementary to the existing experimental phenomena and provide theoretical guidance value for the using of HHP in starch processing.

The effects of HHP (high hydrostatic pressure) on the interchain interaction and the conformation of amylopectin and double-amylose molecules

Starch is an important resource in nature, and HHP (high hydrostatic pressure) is one of the most important physical modification technologies. In this study, molecular dynamics simulation was used to explore the interchain interaction and the changes of molecule conformations of amylopectin and double-amylose helix at atomic level in different pressure. The results shown that, firstly, high pressure increased the content of 4C1 chair conformation, decreased the RMSD (root mean square deviations) and RMSF (root mean square fluctuation), made molecules more stable. Secondly, high pressure increased the interchain VDW (Van der Waals) and electrostatic forces, then caused the decreases of the interchain distances and surface area of both amylopectin and double-amylose, made molecules more compact. Thirdly, high pressure decreased the intramolecular hydrogen bonds, increased the molecule-solvent hydrogen bonds. These findings can explain some existing experimental phenomena from the atomic level, meanwhile, it may also provide importance reference value for using of HHP in starch processing and the studies of starch granule structure.

Self-Assembled Micelles Based on OSA-Modified Starches for Enhancing Solubility of β-Carotene: Effect of Starch Macromolecular Architecture

Self-assembled micelles based on octenyl succinic anhydride (OSA)-modified starch were prepared to enhance the solubility of β-carotene. The critical micelle concentration (CMC) was lower for OSA-modified starch with a lower molecular weight (Mw) or higher degree of substitution (DS). Above the CMC, OSA-modified starch assembled into spherical micelles with an average hydrodynamic diameter of <20 nm, as determined by dynamic light scattering (DLS). All the radii of gyration ( R_g), obtained from Guinier fitting of small-angle X-ray scattering (SAXS) data, were between 3 and 9 nm, and they were positively correlated with the Mw but negatively correlated with both the DS and the starch concentration. β-Carotene was encapsulated effectively into the starch micelles, and the concentration of β-carotene in the micelles was positively correlated with the concentration, Mw, and DS of the starch, with a maximum value of 53.14 μg/mL. The incorporation of β-carotene enlarged the hydrophobic core and induced a significant increase in the R_g of the micelles determined by SAXS, and it may have also promoted the aggregation of the micelles resulting in a marked increase in the D_h determined by DLS.

Co-Processed Excipients for Dispersible Tablets-Part 2: Patient Acceptability

Palatability and patient acceptability are critical attributes of dispersible tablet formulation. Co-processed excipients could provide improved organoleptic profile due to rational choice of excipients and manufacturing techniques. The aim of this study was to identify the most suitable co-processed excipient to use within directly compressible dispersible tablet formulations. Nine excipients, selected based on successful manufacturability, were investigated in a randomised, preference and acceptability testing in 24 healthy adult volunteers. Excipients were classified in order of preference as follows (from most preferred): SmartEx QD100 > F-Melt Type C > F-Melt Type M > MicroceLac > Ludiflash > CombiLac > Pharmaburst 500 > Avicel HFE-102 > Avicel PH-102. Broad differences were identified in terms of acceptability, with SmartEx QD100 being 'very acceptable', F-Melt Type C, F-Melt Type M and MicroceLac being 'acceptable', Ludiflash, CombiLac and Pharmaburst 500 being 'neutral' and Avicel products being 'very unacceptable' based on ratings using five-point hedonic scales. Organoleptic differences were ascribed to different composition and physical properties of excipients, resulting in dissimilar taste and mouth-feel. Excipients with particle size in water larger than 200-250 μm were considered poorly acceptable, which supports the use of this value as a threshold for maximum particle size of dispersible formulation. The most promising co-processed excipients for directly compressible dispersible tablets were successfully identified.

Synthesis, characterization, and antifungal property of starch derivatives modified with quaternary phosphonium salts

Four novel starch derivatives modified with quaternary phosphonium salts were designed and successfully synthesized, including trimethylphosphonium acetyl starch chloride, tributylphosphonium acetyl starch chloride, tricyclohexylphosphonium acetyl starch chloride, triphenylphosphonium acetyl starch chloride, and characterized by FTIR, UV, ¹H NMR, ¹³C NMR, and ³¹P NMR spectra. Their antifungal activities against four kinds of phytopathogens were evaluated using the radial growth assay and minimum inhibitory concentration procedure. The fungicidal assessment revealed that the synthesized starch derivatives had superior antifungal activity compared with starch. Especially, the inhibitory indices of triphenylphosphonium acetyl starch chloride against these four kinds of plant pathogens were higher than 70% at 1.0mg/mL. The results indicated that quaternary phosphonium groups should be high-efficiency antifungal function groups, and meanwhile longer alkyl chain lengths or the stronger electron-withdrawing groups were responsible for enhanced antifungal versatility and efficacy. The cytotoxicity of starch and starch derivatives bearing quaternary phosphonium salts was evaluated in vitro on HEK-293T cells. As novel quaternary phosphonium functionalized starch derivatives could be prepared efficiently and exhibited superduper antifungal activity, this synthetic strategy might provide an effective way and notion to prepare novel antifungal biomaterials.