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There are few studies applying pulsed electric field (PEF) on solid foods in databases. Egg white protein (EWP) was subjected to PEF for elucidating mechanism of changes in molecular structure of enzymes and protein components for solid foods. Determination of free and total sulfhydryl groups, ultraviolet (UV) spectroscopy, infrared (IR) spectroscopy, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were used to compare EWP before and after PEF treatment. The results showed that the amount of free sulfhydryl increased while that of total sulfhydryl decreased after PEF exertion. PEF did not change the SDS-PAGE patterns visibly and no shift in maximum absorption wavelength but intensity could be observed in UV spectra of EWP. IR spectra of EWP were subjected to Gaussian multi-component peak modeling for molecular secondary structure analyses. Either the voltage of the PEF ( P < 0.01) or the residence time of the sample ( P < 0.05) significantly decreased the relative portion of α-helices while increased that of β-sheets in EWP, and impact could also be seen in respect of contents of β-turns and random coils in amide I region of EWP and its fractions. The results are of reference values to potential applications of PEF on solid foods. [ABSTRACT FROM AUTHOR]

Barley is a cereal to seek for higher value added. Its β-glucan has been paid much attention as a soluble dietary fiber. Barley polysaccharide (BP) of a cultivar for brewing was extracted by ultrasonic assistance and derived by using a relatively lower toxic esterifying agent-sulfamic acid to obtain sulfated barley polysaccharides (SBPs) with various degrees of substitution (DS). Comparisons were made amongst SBPs and BP in antioxidant abilities in vitro with total reducing power, scavenging effect on DPPH , hydroxyl radicals, superoxide anion radicals and lipid antioxidation and inhibition against α-glucosidase. The results showed that antioxidant activity of BP was significantly enhanced by sulfation modification. The activities increased with the concentration and DS. Kinetic analyses revealed that the inhibitory effects of SBPs and BP on α-glucosidase were reversible and SBPs exhibited a mixed type of inhibition while BP was a noncompetitively inhibitory process. The present work reflected that BP could be a potential raw material for the development of antiglycemic pharmaceuticals. [ABSTRACT FROM AUTHOR]

Abstract: Pulsed electric field (PEF) treatment was applied to brown rice grains in a treatment chamber which was surrounded by organic glass as walls around a pair of horizontally paralleled plate electrodes to investigate the feasibility of PEF on low moisture food materials. Based on a monolayer of brown rice grains the results showed that the lipase activity could be significantly inactivated by PEF. Among the PEF parameters, the voltage was the most important to the inactivating efficiency, followed by frequency and pulse width; while the time was less dominant. The interactions between voltage and pulse width and between frequency and pulse width also contributed to the lipase inactivation significantly. By using Box–Behnken design, response surface methodology was applied to optimize the process and a well fitting model was obtained with PEF parameters, voltage, frequency, pulse width, and residence time. Industrial relevance: Pulsed electric field (PEF) is a low temperature and environment friendly technology in food processing. It is promising and has received considerable attention over the years in the past. PEF has been applied to inactivate microorganisms or enzymes. However, research work regarding PEF focused almost only on liquid food processing so far. There has been no report of PEF on solid food materials. Rice bran is abundant and nutritious, but it could not be stored for a long time because enzymolysis takes place soon after it is scraped off from rice grains. If the PEF could be used for lipase inactivation in brown rice grains, the stabilized rice bran should be obtained after milling during the material convey. It would be another effective and in-line rice bran stabilization technique potential in the rice industry. Furthermore, the application scope of PEF in food industry could be widened. [Copyright &y& Elsevier]

Abstract: Edible mushrooms have been consumed in Asian countries for healthy functions historically with polysaccharides, which have been manufactured as ending products, as one of the major bioactive components. Driven by profits, some inglorious manufacturers conducted adulteration using cheap carbohydrates. The extracted polysaccharides from Agaricus blazei Murill, Ganoderma lucidum and Lentinus edodes were chosen as products and maltodextrin, carboxymethyl cellulose (CMC), water soluble corn starch and guar gum as adulterants for adulteration investigation. Scanning electron microscope (SEM) observation implied regular granular shapes of fungal polysaccharides different significantly from the adulterants. Infrared spectra revealed α- and β-anomeric types of polysaccharides and carbohydrates. X-ray diffractometry (XRD) suggested different diffraction patterns of polysaccharides from adulterant carbohydrates, the former were amorphous while the later somewhat crystalline of different crystallinity. Chiral properties of polysaccharides and carbohydrates showed big differences in specific rotation with good correlation between the content of “pure” fungal polysaccharides and adulterants. [Copyright &y& Elsevier]

The extracts of Lycium chinense Mill fruits with water, 50% ethanol and 95% ethanol were compared in antiradical efficiency according to the Chinese consumption tradition. The results showed that water infusion was similar to 50% ethanol extract in flavonoids (1154 ± 89 and 1207 ± 66 mg kg−1, respectively), 95% ethanol extract contained more flavonoids (1497 ± 70 mg kg−1). The main flavonoids in Lycium chinense Mill fruits were rutin and chlorogenic acid in water extract, rutin and protocatechuic acid in 50% ethanol extract and rutin in 95% ethanol extract as determined with high-performance liquid chromatography (HPLC). All extracts showed a slow kinetics in DPPH⋅ antiradical reaction system. The antiradical efficiency of the extracts tended to become stronger as the polarity of the solvents decreased. [Copyright &y& Elsevier]

Summary: In this study, pre‐gelatinized highland barley flour (PHBF), pre‐gelatinized sweet potato starch (PSPS), wheat gluten (WG), and egg white protein (EWP) were used to develop highland barley noodles. Their effects on noodle quality were analysed, and then noodle formula optimization was carried out based on them. Changes in quality characteristics and intermolecular structure were analysed to explore the underlying mechanism. PHBF, PSPS, WG, and EWP influence the quality characteristics of HB noodles from diverse angles. After formula optimization, noodles with improved cooking and textural properties were obtained, in which HBF accounts for 93.0% of the composite flour and can be categorised as low expected glycemic index (eGI) foods. The viscosity and elasticity of the dough both improved; a more stable protein structure and enhanced starch structure were formed; and increased intermolecular forces were observed, which would contribute to the enhanced protein cross‐linking, structural order, and textural properties of noodles. [ABSTRACT FROM AUTHOR]

Hydroxypropyl methylcellulose (HPMC)/sodium citrate (SC)/lipid tea polyphenol (LTP) photophobic films with different pore sizes from micron scale to nanometer scale were prepared by regulating the SC content (1–7%). The microstructures, physical and sustained antioxidant properties of these films were studied by using wide angel X-ray diffraction, small angle X-ray scattering (SAXS), scanning electron microscope, whiteness meter, ultraviolet spectrophotometer, texture analyzer and peroxide value test. Composite films with higher SC content showed larger pore size and whiteness. With the increasing SC content, crystallinity first increased then decreased. The addition of SC decreased the D s (surface fractal dimension) value, smoothness of the cross-section structure, tensile strength, elongation and modulus of composite films. HPMC/SC/LTP microporous films possessed control-release property in oil system, reflected by the lowest peroxide value of peanut oil enclosed in film with 3% SC during three weeks, meaning this film showed the best sustained antioxidant property. [ABSTRACT FROM AUTHOR]

In this study, glucan 1,4‐α‐maltotriohydrolase (AMTS) is used to modify corn starch granules to elucidate the structural and physical property changes following AMTS modification. The degree of hydrolysis (DH) of granular corn starch is modulated by adding various amounts of AMTS. Pore structures with more pores, deep channels, and cavities in starch granules with extended hydrolysis are observed by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The short‐range ordered structure, lamellar structure, and crystalline structure are significantly enhanced under moderate AMTS modification, and then slightly decreased with further modification. These structural changes significantly improve oil and water absorption capacities, decrease solubility and swelling power, diminish pasting properties, and lower the digestibility of granular corn starch. When AMTS interferes with the starch system, the specific surface area of granular starch gradually increases with extended hydrolysis, with the maximum being almost 4.6‐fold that of native starch. All these results suggest AMTS hydrolysises of corn starch granules through an "inside‐out" pattern, preferential hydrolysis of the amorphous region, and subsequent alternate hydrolysis of the amorphous and crystalline regions. Overall, AMTS is a potential granular starch hydrolase for producing porous starch used as the carrier material in a variety of food applications. [ABSTRACT FROM AUTHOR]

Photophobic (white) films were prepared with hydroxypropyl methylcellulose (HPMC) and monosodium phosphate (NaH 2 PO 4 ) to overcome the redox reaction induced by titanium dioxide photocatalysis of HPMC/TiO 2 white film. What’s more, HPMC/NaH 2 PO 4 white film could overcome the drying temperature dependent property of white films based on HPMC and calcium salts. Attenuated total reflection Fourier transform infrared spectroscopy, wide angel X-ray diffraction, small angle X-ray scattering, scanning electron microscope and texture analyzer were used to investigate the effect of NaH 2 PO 4 on the short-range, supra-molecular structures and properties of HPMC film. The formation mechanism of the white film was speculated by analyzing the structures of different scales. The results showed that the interaction might happen between H 2 PO 4 −1 group of NaH 2 PO 4 and CH, CH 2 and CH 3 group of HPMC. These interactions influenced the polymer chain movement and combination and further affected the aggregation structures. Specifically, the compactness, smoothness and scale range of the surface fractal scatters in films increased and elongated particles of two scales appeared. These changes of ordered structure in the micro-region might contribute to increasing the reflected light and decreasing the transmission light of films, resulting in white films with photophobic property. The addition of NaH 2 PO 4 decreased the crystallinity and smoothness of the cross-section of HPMC film, which resulted in a little lower tensile strength, elongation and elastic modulus of HPMC/NaH 2 PO 4 films. Films of less than 10% of NaH 2 PO 4 showed similar mechanical properties with pure HPMC film, which offered proper parameters for the production of HPMC/NaH 2 PO 4 photophobic films in the application. [ABSTRACT FROM AUTHOR]

Pulsed electric field (PEF) was applied to moisture-preconditioned canola seeds to evaluate the effect on oil yield. The effect of PEF on functional and structural properties of canola protein left over after oil extraction were also examined in albumin and globulin fractions obtained at optimal conditions for oil yield. Generally, PEF pretreatment significantly improved (P < 0.01) the following functional properties of canola protein and its fractions: solubility, water-holding capacity, emulsibility, emulsion stability, oil-holding capacity, foamability, and foam stability. Infrared spectrometry revealed that the secondary structure of the protein changed upon PEF, as shown by changes in the proportions of α-helices, β-sheets, and β-turns in the amide I region. An increased amount of free sulfhydryl groups and surface hydrophobicity suggested alterations in tertiary structure as well. PEF caused the formation of new protein aggregates with low molecular mass, demonstrated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and changes in the number of total sulfhydryl groups. [ABSTRACT FROM AUTHOR]

Both the effects of enzymolysis condition on the microstructures and emulsifying property of enzymatic modified quinoa starch (EMQS) and the effects of emulsion formulation on the EMQS based emulsions were investigated. The emulsifying capacity (EC) and stability (ES) of EMQS were positive correlated with enzyme amount (0–2.4 % w/w starch). The particle sizes of EMQS decreased and its hydrophobicity increased with increasing enzyme amount (0–2.4 % w/w starch), which were the main reasons for the increasing emulsifying performance of EMQS. With the increasing starch concentration, the EC of the EMQS increased, the oil droplet size of the emulsion decreased. With the oil/water ratios ranging from 1:9 to 6:4, the emulsification index (EI) and oil droplet size of the emulsion increased. EMQS based emulsion had a relatively good stability in the pH range of 2–10. This study lays the foundation for the application of EMQS as a stable clean-label Pickering emulsifier. [ABSTRACT FROM AUTHOR]

The study investigated the effect of removing protein and/or lipid on the physicochemical characteristics and digestibility of sand rice flour (SRF). Morphological images showed that protein removal had a greater impact on exposing starch granules, while lipids acted as an adhesive. The treatment altered starch content in SRF samples, leading to increased starch crystallinity, denser semi-crystalline region, lower onset gelatinization temperature (T o), higher peak viscosity and gelatinization enthalpy (ΔH), where Protein removal showed a more pronounced effect on altering physicochemical properties compared to lipid removal. The research revealed a positive correlation between rapidly digestible starch (RDS), maximum degree of starch hydrolysis (C ∞), digestion rate constant (k) values and 1047/1022 cm−1 ratio, showing a strong connection between short-range structure and starch digestibility. The presence of endogenous proteins and lipids in SRF hinder digestion by restricting starch swelling and gelatinization, and physically obstructing enzyme-starch interaction. Lipids had a greater impact on starch digestibility than proteins, possibly due to their higher efficacy in reducing digestibility, higher lipid content with greater potential to form starch-lipid complexes. This study provides valuable insights into the interaction between starch and proteins/lipids in the sand rice seed matrix, enhancing its applicability in functional and nutritional food products. [ABSTRACT FROM AUTHOR]

The excessive water sensitivity of hydroxypropyl methylcellulose (HPMC) films prevent them from being used extensively. In order to overcome this limitation, superhydrophobic HPMC films were meticulously crafted through the utilization of a composite of polydimethylsiloxane (PDMS) and ball-milled rice starch, corn starch, or potato starch (RS/CS/PS) for the coating process. Initially possessing hydrophilic properties, the HPMC Film (CA = 49.3 ± 1.8°) underwent a transformative hydrophobic conversion upon the application of PDMS, resulting in a static contact angle measuring up to 103.4 ± 2.0°. Notably, the synergistic combination of PDMS-coated HPMC with ball-milled starch demonstrated exceptional superhydrophobic attributes. Particularly, the treated HPMC-based film, specifically the HP-CS-2 h film, showcased an impressive contact angle of 170.5° alongside a minimal sliding angle of 5.2°. The impact of diverse starch types and the ball milling treatment on the PDMS/starch coatings and HPMC film was thoroughly examined using scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXS), and particle size analysis. These studies demonstrated that the low surface energy and roughness required for the creation of superhydrophobic HPMC-based films were imparted by the hierarchical structure formed by the application of PDMS/ball-milled starch. Polydimethylsiloxane (PubChem CID: 24764); Hydroxypropyl methylcellulose (PubChem CID: 671); Ethyl acetate (PubChem CID: 8857). [Display omitted] [ABSTRACT FROM AUTHOR]

Grifola frondosa polysaccharide (GFP2) was extracted and purified by anion‐exchange chromatography. A selenized G. frondosa polysaccharide, SeGFP2, was modified in selenylation by nitric acid–sodium selenite (HNO3‐Na2SeO3) method. Structural features were investigated, and the lymphocyte proliferation and antioxidant activities were compared taking GFP2 as control. SeGFP2 with a molecular weight of 2.12 × 104 Da was composed of mannose, glucose, and galactose with a ratio of 3.5:11.8:1.0. A typical absorption of selenium ester was observed in SeGFP2 molecule. SeGFP2 was proposed as a branched polysaccharide, which consisted of 1,3‐D‐Glcp, 1,6‐D‐Glcp, 1,4,6‐D‐Galp, and 1,3,6‐D‐Manp. SeGFP2 showed a linear filamentous structure with some branches. SeGFP2 could significantly promote T‐ or B‐lymphocyte proliferation and the enhancement was higher than GFP2. The in vitro antioxidant activities of SeGFP2 were more potent than GFP2. These present data suggested that selenylation could significantly improve the lymphocyte proliferation and in vitro antioxidant activities of GFP2. [ABSTRACT FROM AUTHOR]

The lipase (LA) and peroxidase (POD) activities, as well as morphological structure, physicochemical and digestion properties of sand rice flour (SRF) treated with superheated steam (SS), were investigated. SS treatment at 165 °C completely deactivated LA and resulted in a 98% deactivation of POD activities in SRF. This treatment also intensified gelatinization, induced noticeable color alterations, and decreased pasting viscosities. Furthermore, there was a moderate reduction in crystal structure, lamellar structure, and short-range ordered structure, with a pronounced reduction at temperatures exceeding 170 °C. These alterations significantly impacted SRF digestibility, leading to increased levels of rapidly digestible starch (RDS) and resistant starch (RS), with the highest RS content achieved at 165 °C. The effectiveness of SS treatment depends on temperature, with 165 °C being able to stabilize SRF with moderate changes in color and structure. These findings will provide a scientific foundation for SS applicated in SRF stabilization and modification. [Display omitted] • Superheated steam (SS) treatment deactivates lipase and peroxidase. • SS treatment efficiency depends on the temperature input. • SS treatment is potential for sand rice flour stabilization. [ABSTRACT FROM AUTHOR]

• AC electric field (ACEF) acted on peanut protein isolate (PPI) structure and flavor. • Structure and volatile compounds analyzed quantitatively and qualitatively. • ACEF caused alteration of secondary and tertiary structure. • ACEF promising in improving structure and flavor of PPI. The impacts of intensity and treating time of alternating current (AC) electric field (EF) on structure and volatile compounds of peanut protein were investigated for low denaturation. The secondary and tertiary structures, polar and weakly polar volatiles were characterized qualitatively and quantitatively using ultraviolet and fluorescence photospectrometry, free sulfhydryl and disulfide groups determination, and combination of gas chromatography and mass spectrometry. The results showed that the ACEF affected significantly proportions of α-helices, β-sheets, β-turns, and random coils as evidenced by Fourier transform infrared spectrometry. Blue shifts of UV and fluorescence spectra, increased surface hydrophobicity and disulfide bonds could be observed after ACEF treatments. The DB-WAX and DB-5MS columns for the polar and weakly polar volatile compound separation revealed that ACEF caused either disappearance or emerging of volatile compounds. The PCA demonstrated that the two principal components contributed about 70 % or more to the flavor and PLS-DA discriminated 18 key compounds. [ABSTRACT FROM AUTHOR]

[Display omitted] • Less than 3% egg white protein affected the properties of highland barely noodles. • Egg white protein improve protein structure through aggregation and cross-linking. • The working mechanism of egg white protein varied among noodle processing stages. • Effect of egg white protein on the highland barely noodles was does-dependent. • Excessive egg white protein decreased noodles quality and deducted protein network. The effect of egg white protein on the protein structure of highland barely noodles during processing was investigated, and the underlying mechanism was examined. Egg white protein significantly influenced the stress relaxation of highland barley dough. 1% and 2% egg white protein improved the cooking and textural properties of highland barely noodles. During mixing and sheeting, it improved the structure of the protein network by promoting protein aggregation and cross-linking, whereas its effect on non-covalent interactions was quite different. During cooking, egg white protein promoted protein aggregation and cross-linking via heat-induced polymerization, and the distribution regularity of the protein network was improved as its flexibility diminished. The protein structure of highland barely noodles during processing was closely related to the addition amount of egg white protein, and the cooking, textural, and chemical interactions of highland barely noodles during processing changed considerably when more than 3% egg white protein was added. [ABSTRACT FROM AUTHOR]

A small granule starch from sand rice (Agriophyllum squarrosum) was subjected to heat‐moisture treatment (HMT) at different moisture contents (MCs,15%–30%). With MC≤20%, a higher MC resulted in increases in the starch orders (i.e., short‐range and crystalline structure) with unchanged granule morphology. Nonetheless, a further elevated MC (>20%) gradually destroyed the granule morphology and starch orders. Also, HMT gradually vanished the lamellar structure as MC increased during HMT. These structural evolutions in HMT‐modified starch resulted in greater thermal stability, higher pasting temperature, lower pasting viscosity and weakened digestibility. Particularly, HMT applied directly in sand rice starch at 20% MC obtained the highest amount of SDS and RS (23.6%), which was 2.2‐fold higher than that of native starch. Therefore, the small granule sand rice starch can be modulated by HMT through controlled MC to expand their application range in food production. [ABSTRACT FROM AUTHOR]

Quinoa starch was developed as a new kind of Pickering emulsifier by enzymatic modification. The morphological structure, crystalline structure, lamellar structure, fractal structure, particle size distribution, contact angle, emulsion index (EI), and emulsion micromorphology were studied to explore the relationship between structure characteristics, hydrophilic property, and emulsifying properties of enzymatically modified (EM) quinoa starches. With the increasing enzymatic hydrolysis time in the test range of 0–9 h, particle size of EM quinoa starch decreased, and the broken starch and contact angle of EM quinoa starch increased; the EI value of emulsions with EM quinoa starch increased, and the oil droplet size of emulsions with EM quinoa starch decreased. It suggested that both the smallest particle size and the closest extent of the contact angle to 90° derived the best emulsifying property of EM-9. The EM quinoa starch had higher emulsifying capacity at higher oil volume fraction (Φ) (50%) than at lower Φ (20%), proving that the EM starch has potential to be used as Pickering emulsifiers in higher oil products, such as salad dressing. [ABSTRACT FROM AUTHOR]

Different ionic liquid (IL)s were added to hydroxypropyl methylcellulose /monosodium phosphate (HPMC/MSP) photophobic film to improve its ductility, and their effects on its multi-scale structures and physical properties were studied. After adding these ILs, smoothness of the fractal structure, tensile strength, modulus of the film did not change obviously, while the crystallinity, the number of holes, and elongation increased, the hole size and T g decreased. Compared to films with other ILs, the film with 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF 4) showed the largest elongation and crystallinity, the smallest hole size, the least holes, and highest whiteness. The film with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) showed the largest water content and the lowest T g. The increased elongation proved that all these ILs could improve the ductility of the film, among which, [EMIM]BF 4 had the strongest plasticizing effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pulsed, DC and AC electric field (EF) applied on pea protein (PP). • Secondary and tertiary structure of PP changed by EFs. • Intermolecular interactions of PP affected significantly by EFs. • Function properties of PP significantly increased by EFs. • Flavor of PP improved by EFs. Based on the standpoint of low carbon footprint processing and less denaturation of plant protein ingredient, the effects of pulsed electric field (PEF), direct current electric field (DCEF), and alternating current electric field (ACEF) treatments on the structure, functional properties and volatile compounds of pea protein isolate were investigated. The results showed that the electric fields (EFs) caused both blueshifts (max. ∼8 cm−1) and redshifts (max. ∼7 cm−1) in the IR spectra and blueshifts (max. ∼5 nm) in the UV spectra. PEF caused an increase of emulsifying activity index and a decrease of emulsion stability index to DCEF and ACEF. A total of 27 volatile compounds were identified and the EFs could cause emerging of new volatiles and disappearing of inherent volatiles potentially to modify the flavor of products. Alterations were significantly observed among the types of EF, but seldomly among the operating parameter levels in the same EF. [ABSTRACT FROM AUTHOR]

[Display omitted] • Critical melting with freeze–thaw (CMFT) can be used as a clean-label way to prepare porous starch. • Partial weakening of structure before FT is critical for porous starch formation. • Freezing rates determined the pore-forming characteristics of starch. • CMFT-prepared porous starch had more ordered double-helical structures. • CMFT significantly increased the thermostability and water/oil absorption of starch. In this work, critical melting (CM) combined with freeze-thawing treatment (FT, freezing at −20 ℃ and −80 ℃, respectively) was used to prepare porous starch. The results showed that CM combined with the slow freezing rate (−20 ℃) can prepare porous starch with characteristics of grooves and cavities, while combined with the rapid freezing rate (−80 ℃) can prepare with holes and channels, especially after repeating FT cycles. Compared with the native counterpart, the specific surface area, pore volume, and average diameter of CMFT-prepared porous starch were significantly increased to 4.07 m2/g, 7.29 cm3/g × 10−3, and 3.57 nm, respectively. CMFT significantly increased the thermal stability of starch, in which the To, Tp, and Tc significantly increased from 63.32, 69.62, and 72.90 (native) to ∼69, 72, and 76 °C, respectively. CMFT significantly increased water and oil absorption of porous starch from 91.20 % and 72.00 % (native) up to ∼163 % and 94 %, respectively. Moreover, CMFT-prepared porous starch had a more ordered double-helical structure, which showed in the significantly increased relative crystallinity, semi-crystalline lamellae structure, and the proportion of the double helix structure of starch. The synergistic effect of melting combined with ice recrystallization can be used as an effective way to prepare structure-stabilized porous starch. [ABSTRACT FROM AUTHOR]

The impacts of ohmic heating (OH) on the physical structure and volatile compounds of peanut protein (PP) were investigated for low denaturation plant-based meat ingredient using peanut protein isolate (PPI). The microstructure, texture, color, polar and weakly polar volatile compounds were characterized qualitatively and quantitatively using colorimetry, scanning electron microscopy, texture analysis, headspace solid-phase microextraction, DB-WAX and DB-5MS columns for separation, and combination of gas chromatography (GC) and mass spectrometry (MS). The principal component analysis and partial least square discrimination were applied to the results of the volatile compounds attribution. The results showed that OH treatments modified the second and tertiary structure of PP, improved the texture, caused either disappearance of indigenous compounds or emerging of new volatile compounds. OH could reduce off-flavor and increase pleasant compounds of PPI. The findings suggested that the OH is promising in vegetable protein structure and flavor improvement. • Ohmic heating (OH) applied on peanut protein isolate (PPI). • Polar and weakly polar volatiles analyzed quantitatively and qualitatively. • OH promising in improving PPI texture, structure and flavor as base ingredient. [ABSTRACT FROM AUTHOR]

Pulsed electric field (PEF) is promising in food industry in modifying properties of materials. The influences of PEF pretreatment on hydrolysis, texture, multi-scale and semi-crystalline lamellar structure, thermal properties, and flavor of rice were investigated with two special treatments for high and low contents of slowly digestible starch and resistant starch, using enzymatic hydrolysis, scanning electron microscopy, differential scanning calorimetry, X-ray diffractometry, small angle X-ray scattering, attenuated total-reflection Fourier-transform infrared spectrometry, texture profile analysis, and gas chromatography-mass spectrometry (MS)-MS. Upon PEF pretreatment, the starch hydrolysis degree and glycemic index of cooked rice increased slightly; the hardness, springiness, cohesiveness and chewiness of cooked rice increased significantly (P < 0.05). PEF reduced the integrity of cell structure, altered the gelatinization enthalpy, relative crystallinity degree, semi-crystalline layered structure of rice lightly, without obviously changing the diffractive pattern type of rice grains. PEF pretreatment caused decrease of phenols and ketones and increase of acids and aldehydes in cooked rice. • Pulsed electric field (PEF) significantly affected texture of cooked rice. • PEF significantly enhanced starch hydrolysis and increased glycemic index of cooked rice. • PEF significantly changed composition of volatile compounds of rice. [ABSTRACT FROM AUTHOR]

Photophobic (white) films were prepared by mixing hydroxypropyl methylcellulose (HPMC) of different molecular weights with sodium citrate (SC). Wide angle X-ray diffractometry, small angle X-ray scattering, scanning electron microscopy, dynamic mechanical analysis, whiteness determination and texture analysis were used to investigate the effect of HPMC molecular weight on the aggregation structures and properties of HPMC film. The crystalline integrity decreased with the increased molecular weight of HPMC for these HPMC/SC films. Similar crystallinity was observed for 6HPMC/SC and 15HPMC/SC, which was larger than that of 50HPMC/SC. All the three HPMC/SC film showed surface fractal structure with similar D s. With the increasing molecular weight of HPMC, the HPMC/SC film showed honeycomb structures with smaller holes and more compact porous structure, T g first increased and then decreased a little, the tensile strength and elongation increased with the increasing HPMC molecular weight. 50HPMC/SC films with the smallest pores showed the largest whiteness. A new T g ' peak was observed for HPMC/SC film. • Effect of HPMC molar mass on structural properties of HPMC/SC films was studied. • The HPMC/SC film with higher HPMC molar mass showed smaller and more compact holes. • The tensile strength and elongation increased with the increasing molar mass of HPMC. • 50 HPMC/SC films with the smallest pores showed the largest whiteness. • New T g ′ peak was observed for HPMC/SC film, with the most obvious for 6 HPMC/SC film. [ABSTRACT FROM AUTHOR]

Poor quality of barley hinders badly the beer production in China. α-Amylase activity plays a very important role in malted barley (Hordeum vulgare L.) for beer production during the mashing process. Pulsed electric field (PEF) and Ca2+ in the form of CaCl2 were introduced to elevate α-amylase activity of barley malt for modifying the quality, and positive consequences emerged. The influences of PEF operating parameters on α-amylase activity were investigated, and the parameter settings were optimized based on factorial experiments, and a highly (R2 = 0.9859) correlated regression model was established using response surface methodology. An increment of about 29% for α-amylase activity was achieved at the optimal parameter settings as 8 kV of pulse voltage, 500 Hz of pulse frequency, 8 μs of pulse width, and 14 min of material residence time. The incorporation of PEF with Ca2+ demonstrated much better functions than the utilization of PEF or Ca2+ alone. The orthogonal experiment design was adopted to optimize the conditions for incorporation of PEF with Ca2+, and it showed that at 8 kV of pulse voltage, 500 Hz of pulse frequency, 7 μs of pulse width, 12 min of material residence time, and 80 mg L−1 of Ca2+ concentration, the largest increment of over 54% for α-amylase activity was obtained. Evaluations of PEF and Ca2+ on Amy6-4, the gene responsible for α-amylase in barley seed, were made to look into the mechanism how they functioned in barley malting, and it was found that the elevation of α-amylase activity was because of the significant (P < 0.05) increase of the amounts of total RNA and Amy6-4 expression. [ABSTRACT FROM AUTHOR]

Highlights • Effect of PEF on structural properties of starches type A, B, and C investigated. • Polarized light microscopy, XRD, ATR-FTIR, SSNMR, SAXS, GPC used. • Effect of PEF on structure and in vitro digestibility of starch patterns revealed. Abstract Effect of pulsed electric field (PEF) on the structural properties of representative starches with different crystalline type, wheat starch for type A, potato starch for type B, and pea starch for type C, were investigated with polarized light microscopy (PLM), X-ray diffractometry (XRD), attenuated total internal reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, solid-state nuclear magnetic resonance (SSNMR) spectroscopy, small-angle X-ray scattering (SAXS), and gel permeation chromatography (GPC) to understand whether PEF could be applied directly in starchy foods. The results showed that PEF could change the structure of all three types of starch, especially potato starch; the birefringence, represented by Maltese cross in polarized microscopic observation changed slightly; XRD and SSNMR spectra demonstrated PEF did not change the crystalline type of starch granules. However, relative crystallinity variations happened at some points of electric field intensity (EFI). Increasing with the EFI, a bigger variation of R 1045/1022 happened in potato starch than in wheat starch and pea starch, as illustrated by ATR-FTIR. Significant influences of PEF on the scatter structure and fractal dimension of self-similar structures were observed for wheat starch and potato starch, but not for pea starch. The GPC suggested that molecular weight distribution changed for all the three starches. And in vitro tests showed that PEF changed significantly (P < 0.05) the digestibility of starches, especially wheat starch and potato starch. [ABSTRACT FROM AUTHOR]

Abstract Monosodium phosphate (MP), sodium citrate (SC), sodium lactate (SL) and magnesium citrate (MC) can be blended with hydroxypropyl methylcellulose (HPMC) to make photophobic (white) films at lower drying temperatures. Small angle X-ray scattering (SAXS), wide angle X-ray diffraction (XRD), scanning electron microscopy (SEM), whiteness determination, dynamic mechanical analysis (DMA) and texture analysis were adopted to study the variation of microstructures and properties. These four kinds of HPMC/salt films showed decreased crystallinity and increased compactness and smoothness of the self-similar structures in larger scale ranges. HPMC/MP, HPMC/SC and HPMC/SL film showed coarser and porous morphologies, lower mechanical parameters and higher whiteness than pure HPMC film. HPMC/MC film showed smoother morphologies, higher tensile strength, elongation and whiteness than pure HPMC film. Porous structures and more compact self-similar structures might contribute to the photophobic property of these films, and relatively smooth morphology might dominate the increasing mechanical parameters of HPMC/MC film. [ABSTRACT FROM AUTHOR]

Highlights • Smaller granules had the fewest lamellar structure. • The fractal structure of SPS showed the lowest compactness. • The fractal structure of SCS showed the highest compactness. • SPS had the highest total double helix content. • LCS showed a new diffractive peak at 24.3°, and SPS showed a new 13C peak at 64 ppm. Abstract Large-, medium-, and small-sized granules were separated from cassava and potato starches. Fourier transform infrared spectroscopy, wide angle X-ray diffraction, small angle X-ray scattering, nuclear magnetic resonance and scanning electron microscope were used to investigate the supramolecular structures of cassava and potato starch fractions. The crystallinity of small-sized potato starch (SPS) was lower than that of its counterparts, while crystallinities of all cassava fractions were similar. The contents of lamellar structure of small-sized granules were the smallest, while those of their counterparts were similar. The lamellar repeat distance was similar for the starch fractions. Self-similar structure of SPS showed mass fractal with the lowest compactness, while that of small-sized corn starch showed surface fractal with the largest compactness. The NMR test revealed that SPS had the highest total double helix content, while its counterparts showed similar values. Moreover, a new 13C peak at 64 ppm was observed for SPS. [ABSTRACT FROM AUTHOR]

In this study, rice starch (RS) was mixed with varying amounts of rice protein (RP; 0 % to 16 %) to explore the effects of protein on the gelatinization and retrogradation of starch during storage. The increased RP addition decreased the viscosity and gelatinization enthalpy of the mixtures but caused an upward trend in the gelatinization temperature, indicating that protein hampers the process of starch gelatinization. Furthermore, RP addition reduced gel hardness, decreased retrogradation enthalpy and crystallization rate constant, but increased Avrami exponent upon RS retrogradation. RP addition also facilitated the mobility of water molecules, weakened the conversion from bound water to free water in the gels, and moderately increased the uniformity and thickness of gel shape. In summary, RP had a dose-dependent effect on the gelatinization and retrogradation behavior of RS, although the anti-retrogradation concentration effect strongly weakened at protein levels exceeding 12 %. It is noteworthy, that excessive RP addition resulted in disulfide bond formation, which increased gel strength and network structure but reduced the ability of RP to facilitate water molecule mobility and restrict water migration, ultimately reducing its anti-retrogradation capability. This phenomenon can be partially attributed to spontaneous protein-protein interaction caused by excessive protein addition, replacing the starch-protein interaction. [ABSTRACT FROM AUTHOR]

In this study, rice starch (RS) was mixed with varying amounts of rice protein (RP; 0 % to 16 %) to explore the effects of protein on the gelatinization and retrogradation of starch during storage. The increased RP addition decreased the viscosity and gelatinization enthalpy of the mixtures but caused an upward trend in the gelatinization temperature, indicating that protein hampers the process of starch gelatinization. Furthermore, RP addition reduced gel hardness, decreased retrogradation enthalpy and crystallization rate constant, but increased Avrami exponent upon RS retrogradation. RP addition also facilitated the mobility of water molecules, weakened the conversion from bound water to free water in the gels, and moderately increased the uniformity and thickness of gel shape. In summary, RP had a dose-dependent effect on the gelatinization and retrogradation behavior of RS, although the anti-retrogradation concentration effect strongly weakened at protein levels exceeding 12 %. It is noteworthy, that excessive RP addition resulted in disulfide bond formation, which increased gel strength and network structure but reduced the ability of RP to facilitate water molecule mobility and restrict water migration, ultimately reducing its anti-retrogradation capability. This phenomenon can be partially attributed to spontaneous protein-protein interaction caused by excessive protein addition, replacing the starch-protein interaction. [ABSTRACT FROM AUTHOR]

The limited and unstable interactions between potato starch (PS) and xanthan gum (XG) by simple mixing (SM) lead it difficult to induce substantial changes in starchy products. Structural unwinding and rearrangement of PS and XG by critical melting and freeze-thawing (CMFT) were used to promote PS/XG synergism, and the physicochemical, functionalities, and structural properties were investigated. Compared to "Native" and SM, CMFT promoted the formation of large clusters with a rough granular surface and wrapped by a matrix composed of released soluble starches and XG (SEM), thus making the composite more compact to thermal processes, such as the significantly decreased WSI and SP, and increased the melting temperatures. The enhanced synergism of PS/XG after CMFT effectively decreased the breakdown viscosity from ~3600 (Native) to ~300 mPa·s and increased the final viscosity from ~2800 (Native) to ~4800. CMFT significantly increased the functional properties of PS/XG composite, including water/oil absorptions and resistant starch content. CMFT caused the partial melting and loss of large packaged structures in starch (XRD, FTIR, and NMR), and the melting and the loss of crystalline structure controlled at approximately 20 % and 30 %, respectively, are the most effective for promoting PS/XG interaction. • Critical melting and freeze-thawing (CMFT) enhanced potato starch/xanthan gum (PS/XG) interaction. • Starch melting and crystalline loss controlled at ~20 % and 30 %, respectively, are the most effective. • Soluble starches released by CMFT are beneficial to promote PS/XG interchain entanglement. • CMFT increased the functional properties of starch with decreased digestibility. • CMFT effectively raised the thermal, heating, and shear stability of starch. [ABSTRACT FROM AUTHOR]

Se-polysaccharide (Se-GFP-22) from Se-enriched Grifola frondosa has double and cooperative activities of polysaccharide and Se. To delineate the underlying mechanism and signaling cascade involved in immune-stimulatory property of Se-GFP-22, the production of cellular mediators and key proteins in signaling pathway was examined. Results showed that Se-GFP-22 exhibited no cytotoxic and had a high capacity to promote macrophage phagocytosis, up-regulate interleukin-2 (IL-2), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and nitric oxide (NO) productions, as well as the relative messenger RNA (mRNA) expressions. In Se-GFP-22-induced macrophages, intracellular superoxide dismutase (SOD) activity was significantly increased to protect cells from oxidative injury. However, Se-GFP-22 induced macrophage activation was suppressed when the toll-like receptor 4 (TLR4) signaling pathway was blocked by a specific TLR4 inhibitor. According to the western blot analysis and the use of specific inhibitors against the mitogen-activated protein kinases (MAPK) signaling pathway, we speculated that Se-GFP-22 activated RAW264.7 macrophages through the TLR4-mediated MAPK signaling pathway. This study provides a molecular basis for the potential of Se-GFP-22 as a novel immune-stimulatory agent. • The immunomodulatory effect and the underlying mechanism of Se-GFP-22 were studied. • Se-GFP-22 promoted the secretion of NO, IL-2, TNF-α and IFN-γ in RAW264.7. • Se-GFP-22 upregulated mRNA expression of iNOS, IL-2, TNF-α and IFN-γ. • Se-GFP-22 activated the immune-stimulatory effects via TLR4/MyD88/MAPK pathway. [ABSTRACT FROM AUTHOR]

The effect of an interchain entanglement on the enhancement of starch and hydrocolloid synergism and their changes in structural and functional properties was investigated. Potato starch (PS) and xanthan gum (XG) were taken as research materials, and critical melting at the onset melting temperature of starch combined with freeze-thawing (CMFT) was used to promote interchain entanglement of PS/XG. The work suggested that CMFT effectively stabilized the aqueous mixture system of PS/XG, showing no phase separation in the water phase system, even after 12 h of storage. The PS/XG composite prepared by CMFT had significantly improved stability against acid, salt, and shear stress during the thermal process DSC demonstrated that CMFT raised the T o of composite to ∼67 from 62.79 °C for native PS. RVA suggested that when pasted in distilled water, acid, and salt solution media, the breakdown viscosity of PS/XG composite declined to ∼380, 660, and 240 from 3615, 1541, and 1114 mPa s for native PS, respectively. CMFT significantly affected the apparent dropping properties of the starch paste, displaying a shorter and more cohesive paste drop against gravity. CMFT effectively improved the gelling properties of starch, with significant improvement in apparent surface adhesion properties and texture of gels, as well as freeze-thawing stability. [Display omitted] •Critical melting and freeze-thawing (CMFT) enhanced potato starch/xanthan gum (PS/XG) synergism. •Release of soluble starches by CMFT effectively promotes interchain entanglement with XG. •Partial melting of the ordered crystalline structure is beneficial to promoting PS/XG interaction. •CMFT significantly improved the pasting and gelling properties of starch. •CMFT effectively raised the thermal, acid, salt, and shear stability of starch paste. [ABSTRACT FROM AUTHOR]

To assess the efficacy of electric field (EF) on vegetable protein juice-holding and texturisation as a low denaturation processing means, the impacts of pulsed (PEF) and low direct current (DCEF) electric field on the water- (WHC) and oil-holding capacity (OHC), microstructure, texture and physical structure of wheat gluten were investigated using wet gluten dough. The results showed that the PEF and DCEF affected the WHC and OHC significantly. The PEF seemed not to affect the textural properties so severely although significant differences appeared in hardness, chewiness, gumminess, and cohesiveness; there were no significant differences either in springiness or in resilience. The DCEF had a stronger impact on all the textural indices. Scanning electronic microscopy suggested that the PEF caused smaller and uniform micropores and the DCEF derivated more continuous and compact microstructure. Fourier transform infrared spectrometry demonstrated that EF significantly altered the composition proportion of the secondary structure. A slight blue shifts of UV spectra, a red shift of fluorescence spectra, and an increased surface hydrophobicity of gluten could be observed after EF treatment. X-ray diffractometry demonstrated that the EF significantly made the physical structure of wet gluten compacter. The results suggested that EF is promising in vegetable protein texturisation. • Effect of Pulsed (PEF) and DC (DCEF) electric field on wet gluten compared. • Water- and oil-holding ability, texture, microstructure, physical structure investigated. • PEF and DCEF affected texture and microstructure as massager and presser. • Both fields caused alteration of secondary and tertiary structure. [ABSTRACT FROM AUTHOR]

Hydroxypropyl methylcellulose (HPMC) and curdlan (CL) were used to prepare uniform films. The influence of the composition ratios and drying temperature on the microstructures, compatibility and physical performance of HPMC/CL films were studied. The crystalline peaks corresponding to CL component of HPMC/CL films increased with the increasing CL content. Increasing CL content resulted in increased hydrogen bonds in HPMC/CL film, reduced transmittance at 500 nm, oxygen permeability and water solubility of the HPMC/CL films. Higher drying temperature led to increased phase separation and decreased physical properties of pure HPMC film, and led to increased compatibility, cross-section smoothness, oxygen barrier property and mechanical properties of pure CL and blending films. [ABSTRACT FROM AUTHOR]

Porous starch is one of the widely used multifunctional materials in food and pharmaceutical industries. This work was carried out to prepare porous starch by a novel clean-label method of critical melting (CM) and freeze-thawing (FT) treatment. Porous starch prepared by CMFT showed observable grooves and holes on the surface, channels and cavities inside the granule. Repeated FT after CM promoted the formation of porous structures, in which freezing rates showed different effects on the pore-forming properties of starch granules. Compared to the native counterpart, porous starch prepared by CMFT showed significantly increased thermal stability as shown by water solubility, swelling power, DSC, and RVA. CMFT treatment significantly increased water and oil absorption of porous starch from 85 to 75% (native) up to about 160 and 100%, respectively. Moreover, CMFT prepared porous starch showed the appearance of a visible diffraction peak at 20°, indicating a more ordered double-helical structure in starch granules. The synergistic effect of CM combined with FT could be used to prepare porous starch with "clean-label". [Display omitted] • Critical melting with freeze-thawing could be used for porous starch preparation. • The prepared porous starch has an increased thermostability. • Treatment significantly increased the water and oil absorption of porous starch. • Melting energy and ice crystals recrystallization are critical for porous structure formation. • Reassociation of leached soluble starches during treatment raised thermostability of starch. [ABSTRACT FROM AUTHOR]

[Display omitted] • Partial gelatinization and freeze-thawing significantly modified the properties of waxy maize starch. • The addition of xanthan gum enhanced these effects of physical treatments. • Treatments affected inner structure and chain arrangement of starch. • Treatments improved the pasting properties and produced a short and cohesive paste. • Treatments increased the gelling ability and stability to freeze-thawing cycles. To improve the pasting and gelling behaviors of waxy maize starch, an aqueous dispersion with or without xanthan gum was subjected to partial gelatinization (5 ℃ above the onset melting temperature of starch) and freeze-thawing treatment. After the treatments, starch granules were slightly deformed, with partial loss of birefringence, and tended to aggregate. The relative crystallinity and thermal stability of waxy maize starch crystals decreased by the treatments. These changes indicated that the treatment affected the inner structure and chain arrangement of the granules. The treated waxy maize starches, however, showed a higher overall pasting viscosity with shorter and more cohesive pastes than that of the native starch. The treated starches formed rigid gels with increased stability against freeze-thawing. The addition of small amounts of xanthan gum enhanced the effects of the treatments. [ABSTRACT FROM AUTHOR]

Critical melting pretreatment for granular swelling and soluble starch release was performed before freeze-thawing (FT) to enhance the effect of FT treatment on structure modification of potato starch. The critical melting temperature applied was based on the onset melting temperature (T o) of the native potato starch. After pretreatment, the effect of multiple FT cycles on the morphology, structure, and functionality was investigated. The pretreatment effectively induced granular swelling and partial disruption of the crystalline structure by increasing the volume of water molecules inside the granules. The pasting pattern changed obviously after treatments with the significantly increased final viscosity (up to 5000 from 2900 mPa s) and decreased breakdown (1/5th of native starch). Soluble starch released due to the both critical melting and FT treatments had a strong tendency to reassociate outside the granules, which effectively raised the thermal stability of starch granules. Moreover, increased water (∼109–∼164%) and oil (∼56–∼64%) absorption of starch at room temperature were observed. The synergistic effect of the combination of critical melting pretreatment and mechanical force of ice crystals effectively modified the properties of potato starch, suggesting a useful clean-label method for starch modification. [Display omitted] • Pretreatment enhanced modification effect of freeze-thawing on potato starch (PS). • Critical melting pretreatment applied is based on onset melting temperature of PS. • The combined treatment changed the morphology, structure, and functionality of PS. • Thermal stability of PS granules raised significantly after the combined treatment. • Partial disruption of chain arrangement and soluble starch release plays a key role. [ABSTRACT FROM AUTHOR]

An aqueous suspension of native potato starch (PS)/xanthan gum (XG) mixture was subjected to physical treatments, including critical melting (mild heating, MH; partial gelatinization, PG) and freeze-thawing (FT) treatments. The Physical treatments significantly changed the morphology, pasting, and structural characteristics of potato starch compared with the simple aqueous blending of PS and XG. Microscopy revealed that the starch granules partially melted and some of the melted granules aggregated into a cluster after critical melting and FT treatment. The overall intensity of X-ray diffraction peaks and relative crystallinity also decreased obviously after treatment, indicating partial disruption of the starch inner structure. Both XG addition and physical treatment decreased the solubility index, swelling power, and water holding capacity of starch after physical treatments. Moreover, the final viscosity (from 2988 to about 5000 mPa s) and shear stability (from 3542 to about 200 mPa s) of starch paste were substantially increased by the physical treatments. The critical melting caused the leaching of soluble starch, which induced the formation of starch/XG aggregate matrix attached to the surface of starch granules during FT treatment, contributing to the starch property modification. While the formation of these matrices might also be the reason for the increased thickness of the starch semi-crystalline lamellar structure. [Display omitted] • Critical melting and freeze-thawing treatments with xanthan gum (XG) effectively modified potato starch. • Treatments significantly changed the morphology, pasting and structural characteristics of starch. • Formation of soluble starch/XG matrix during treatments stabilized the starch granules against heating. • Treatments raised the final viscosity and shear stability of starch pastes. • Intensity of X-ray diffraction peaks and relative crystallinity decreased obviously after treatments. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the probiotic effects of Lactobacillus strains against Vibrio parahaemolyticus causing gastroenteritis. Six-week-old ICR mice were pretreated with four Lactobacillus strains at three dosages, and then challenged with V. parahaemolyticus TGqx01 (serotype O3: K6). The results showed that V. parahaemolyticus TGqx01 caused severe intestinal fluid accumulation ( FA) and villi damage in control mice which were pretreated with phosphate-buffered saline. In contrast, significant alleviation of FA was seen in mice pretreated by with a high dose of Lactobacillus strains ( P < 0.05, n = 6) but not in mice that received low-dose pretreatments. Among middle-dose treatments, two highly adhesive strains, Lactobacillus rhamnosus H15 and Lactobacillus brevis Y29-4, significantly decreased intestinal FA and villi damage in treated mice ( P < 0.05). Two low-adhesive strains, Lactobacillus acidophilus Y14-3 and Lactobacillus fermentum F16-6, had no significant alleviating effects. At the same dosing levels, no significant differences in FA were observed in mice pretreated with strains with similar adhesive abilities but different antagonistic activities. Our findings suggest that Lactobacillus strains can alleviate V. parahaemolyticus-induced intestinal FA in mice, and the doses required for in vivo efficacy depend more on adhesive ability than on the antibacterial activity of strains. [ABSTRACT FROM AUTHOR]

Pulsed electric field (PEF) was efficient in inactivating lipase in wheat grains. To understand the modification in wheat components, the functional, rheological, and structural properties of vital wheat gluten (VWG) were evaluated after PEF treatment. The results showed that the PEF parameters, electric field intensity (EFI), pulse frequency, pulse width, and material residence time significantly (P < 0.01) affected the solubility, water-holding capacity, oil-holding capacity, foaming capacity, foam stability, and emulsion stability to different extents. The transition temperature and denaturation enthalpy of gluten protein decreased significantly (P < 0.01). The elastic modulus, viscous modulus, tanδ of the wet gluten protein, and the apparent viscosity of VWG changed slightly; however, they changed significantly (P < 0.05) with the increase in EFI. Larger EFIs resulted in a more homogeneously condensed and evenly distributed wet gluten pore. The proportion of α-helices and β-sheets had decreased and increased with the increase in EFI, respectively, while the proportion of random coils changed insignificantly (P > 0.05). The amount of free and total sulfhydryl increased and decreased significantly (P < 0.01) with an increase in EFI, respectively. Surface hydrophobicity was significantly reduced (P < 0.01). • Pulsed electric field (PEF) was applied to dry wheat gluten powder. • Functional, rheological and structural properties were investigated. • PEF showed significant actions on gluten protein properties to different extent. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ductility increased with the increase of [EMIM]Ac. • The pore size and pore number can be regulated by changing the [EMIM]Ac content. • After adding [EMIM]Ac, the film still kept good photophobic property. • The improved films have potential to be used as packaging for light sensitive foods. X-ray diffraction, small angel X-ray scattering, scanning electron microscopy, moisture determination, dynamic mechanical analysis, whiteness assay and mechanical testing were used to study the effects of different doses of [EMIM]Ac on the microstructures and physical properties of HPMC/MSP film. By adjusting the 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) content (0 %–8 %), the mechanical properties and microstructures could be regulated. The elongation of the film increased from 5.91 % to 12.83 % with the increasing [EMIM]Ac content from 0% to 8% without affecting the tensile strength and modulus significantly. The average pore area decreased from 0.82 μm2 to 0.05 μm2 and the pore number increased with the increasing [EMIM]Ac content from 0% to 8%. Moreover, with the increasing [EMIM]Ac content, T g decreased. 6% and 8% [EMIM]Ac decreased the compactness and smoothness of the fractal structure of the film greatly. [EMIM]Ac improved the ductility of HPMC/MSP film, which was mainly due to the decreased pore size and T g. The improved photophobic films are both flexible and with easily changeable porous structure, which can be used as controllable packaging to carry and control-release different functional agents for different light sensitive foods. [ABSTRACT FROM AUTHOR]

Rice accounts for more than half the global population as staple food with starch predominating the major component. The effect of pulsed electric field (PEF) on thermal, paste and digestible properties, morphology, and hierarchical structure of rice starch in solid state was investigated. Upon PEF treatment, the gelatinization enthalpy (Δ Η) of starch decreased, the retrogradation value of starch paste decreased slightly; and the rapid digestible starch (RDS) increased, the slowly digestible starch (SDS) decreased and the resistant starch (RS) changed slightly. PEF might act on the outer structure of starch granules, slightly changed the molecular structure of rice starch by rearranging the short-range structure and damaging the amorphous and crystalline structure. Pearson correlation analysis suggested that molecular weight of amylopectin, Δ Η and digestibility were strongly dependent on the electric field strength; the changes in multi-scale structure was closely related to those in properties of PEF. The improvement of digestibility of rice starch might be attributed to the disruption of starch granule surface as evidenced by SEM observation and the rearrangement of multi-scale structures of rice starch induced by PEF. • PEF can modulate the properties and multi-scale structures of rice starch. • M w of amylopectin, ΔΗ and digestibility changes depending on the EFI input. • The digestibility improvement attributes to rearrangement of starch structures. [ABSTRACT FROM AUTHOR]