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This study aimed to in v estigate the effect of non-covalent interactions between different concentrations (0.1–1.2 %, w / v) of hyaluronic acid (HA) and 3 % (w / v) whey protein isolate (WPI) on the stability of oil-in-water emulsions. Non-covalent interactions between WPI and HA were detected using Fourier-transform infrared spectroscopy. The addition of HA increased the electrostatic repulsion between molecules and reduced the particle size of WPI. Circular dichroism spectroscopy results indicated that the addition of HA caused an increase in β-sheet content and a decrease in α-helix and random coil content in WPI. Moreover, HA increased the emulsion viscosity and strength of the interfacial network structure. Micrographs obtained using confocal laser scanning microscopy indicated that the emulsion with 0.8 % (w / v) HA exhibited good dispersion and homogeneity after storage for 14 d. Complexation with HA significantly altered the rheological and emulsifying properties of WPI, providing an emulsion with excellent stability under heating treatment, freeze-thawing treatment and centrifugation. The results provide a potential for HA application in emulsified foods. • The properties of the WPI-HA complex were tested at different HA concentrations. • HA had a strong non-covalent interaction with WPI. • HA promoted the absorption of protein on the oil droplet surface. • The addition of HA prevented aggregation of WPI. • The stability of the emulsions stabilized by the WPI-HA complex was improved. [ABSTRACT FROM AUTHOR]

For Codonopsis Radix polysaccharides (CRPs), oral administration is generally considered the most convenient route for patients. However, the details of its absorption and transport mechanisms remain unclear. In this study, we aimed to evaluate the oral absorption of CPA (an inulin-type fructan extracted from CRPs) in mice and Caco-2 cells. It was labeled with fluorescein isothiocyanate, and the fluorescence derivative (FCPA) was used to trace the behavior of CPA. The results showed that FCPA could be absorbed after oral administration and has a wide tissue distribution, including in the stomach, intestine, kidneys, and liver. FCPA was poorly absorbed, and its internalization was time- and energy-dependent, as well as dependent on cholesterol- and dynamin-mediated endocytosis. Confocal laser scanning microscopy showed successful cellular internalization of FCPA from the cytoplasm to the nucleus. In addition, we found that FCPA was trafficked to endosomes and lysosomes, and that tubulin was required for its intracellular transport. These findings add new details to our knowledge of the internalization and transport mechanisms of CPA, which may prove useful to the development and application of oral formulations of CRPs. [ABSTRACT FROM AUTHOR]

To develop natural complex materials as starch-dominated emulsifiers, pregelatinization was conducted on potato flour. The effects of gelatinization degrees (GDs, 0 %–50 %) on the structural characteristics, physicochemical properties, and emulsifying potentials of potato flour were investigated. Increasing GD of potato flour promoted protein aggregation on starch granules surfaces and transformed starch semicrystalline structures into melted networks. The emulsion stabilized with 50 % GD potato flour exhibited excellent storage stability (7 d) and gel-like behavior. With increasing GD from 0 to 50 %, the respective apparent viscosities and elastic moduli of emulsion increased from 21.4 Pa to 1126.7 Pa, and from 0.133 Pa·s to 1176.6 Pa·s, promoting the formation of a stable network structure in the emulsion. Fourier transform infrared spectra from emulsions with a continuous phase of >20 % GD displayed a new peak around 1740 cm−1, suggesting improved covalent interactions between droplets, thereby facilitating emulsion stability. Confocal laser scanning microscopy images indicated that droplets could be anchored in the melted networks and broken starch granules, inhibiting droplets coalescence. These results suggest that pregelatinization is a viable strategy for customizing natural starch-dominated emulsions. [Display omitted] • Emulsions stabilized by pregelatinized potato flour were successfully fabricated. • Proteins were aggregated on the surface of starch in the gelatinized potato flour. • Increased gelatinization degree of potato flour enhanced the stability of emulsion. • The enhancement of emulsification was due to increasing interactions of components. [ABSTRACT FROM AUTHOR]

Glutinous sorghum grains were soaked (60–80 °C, 2–8 h) to explore the effects of soaking, an essential step in industrial processing of brewing, on starch. As the soaking temperature increased, the peak viscosity and crystallinity of starch gradually decreased, while the enzymatic hydrolysis rate and storage modulus first increased and then decreased. At 70 °C, the content of amylose, the enzymatic hydrolysis rate of starch, and the final viscosity first increase and then decrease with the increase of soaking time, reaching their maximum at 6 h, increased by 53.1 %, 11.0 %, and 10.4 %, respectively, as compared with the non-soaked sample. At 80 °C (4 h), the laser confocal microscopy images showed a network structure formed between the denatured protein chains and the leached-out amylose chains. The molecular weights of starch before and after soaking were all in the range of 3.82–8.98 × 107 g/mol. Since 70 °C is lower than that of starch gelatinization and protein denaturation, when soaking for 6 h, the enzymatic hydrolysis rate of starch is the highest, and the growth of miscellaneous bacteria is inhibited, which is beneficial for subsequent processing technology. The result provides a theoretical basis for the intelligent control of glutinous sorghum brewing. [Display omitted] • Soaking at 70 °C for 6 h, the enzymatic hydrolysis rate of starch is the highest. • As the soaking temperature increases, the starch granules swell, deform and break. • Networks formed between starch and protein by soaking glutinous sorghum. [ABSTRACT FROM AUTHOR]

Reducing sodium in foods has attracted the attention of consumers, it is therefore necessary to explore sodium alternatives (i.e., low-sodium salt). However, the mechanism of low-sodium salt on gluten in dough remains unclear. Effect of low-sodium salt on the aggregation behaviors of gluten in dough was investigated and compared with those with NaCl and KCl in this study. The results showed that low-sodium salt enhanced gluten strength and prolonged gluten aggregation time. Low-sodium salt decreased the content of SDS extractable protein under non-reducing conditions. Low-sodium salt changed the spatial conformation of gluten by reducing β-turn structure and increasing β-sheet structure. Confocal laser scanning microscopy images indicated that low-sodium salt promoted the formation of a larger and dense gluten network. In summary, this study showed that low-sodium salt promoted the aggregation of gluten in dough, and the change of gluten structure explained this aggregation mechanism. Its mode of action was similar to NaCl and KCl, which provided a theoretical basis for the study of sodium substitutes in flour products. • Low-sodium salt enhanced gluten strength and prolonged gluten aggregation time. • Low-sodium salt reduced SDS extractable protein content in dough. • Low-sodium salt increased D 32 and D 43 of gluten in dough. • Low-sodium salt changed spatial structure of gluten in dough. • Low-sodium salt promoted the formation of a larger and dense gluten network. [ABSTRACT FROM AUTHOR]

Kudzu, a plant known for its medicinal value and health benefits, is typically consumed in the form of starch. However, the use of native kudzu starch is limited by its high pasting temperature and low solubility, leading to a poor consumer experience. In this study, kudzu starch was treated using six modification techniques: ball milling, extrusion puffing, alcoholic-alkaline, urea-alkaline, pullulanase, and extrusion puffing-pullulanase. The results of the Fourier transform infrared spectrum showed that the intensity ratio of 1047/1022 cm−1 for the modified starches (1.02–1.21) was lower than that of the native kudzu starch (1.22). The relative crystallinity of modified kudzu starch significantly decreased, especially after ball milling, extrusion puffing, and alcoholic-alkaline treatment. Furthermore, scanning electron microscopy and confocal laser scanning microscopy revealed significant changes in the granular structures of the modified starches. After modification, the pasting temperature of kudzu starch decreased (except for the urea-alkaline treatment), and the apparent viscosity of kudzu starch decreased from 517.95 Pa·s to 0.47 Pa·s. The cold-water solubility of extrusion-puffing and extrusion puffing-pullulanase modified kudzu starch was >70 %, which was significantly higher than that of the native starch (0.11 %). These findings establish a theoretical basis for the potential development of instant kudzu powder. • Effect of six modification methods on the structural properties of kudzu starch • The cold-water solubility of starch increased by 700 times after extrusion puffing. • Six modification methods positively affected the properties of kudzu starch. • Six modifications reduced the pasting temperature of kudzu starch. [ABSTRACT FROM AUTHOR]

Enzyme immobilization usually make use of nanomaterials to hold up biocatalysis stability in various unamiable reaction conditions, but also lead large discount on enzyme activity. Thus, there are abundant researches focus on how to deal with the relation of enzyme molecules and supports. In this work, a new state of highly active enzymes has been established through facile and novel in situ immobilization and soft template removal method to construct enzyme contained hollow silica nanosphere (catalase@HSN) biocatalysts where enzymes in the cavity exhibit "immobilized but not rigid state". The obtained catalase@HSN was characterized by transmission electron microscopy, scanning electron microscopy and confocal laser scanning microscopy et al. Catalase@HSN exhibits excellent activity (about 80 % activity recovery rate) and stability suffers from extreme pH, temperature, and organic solvents. Moreover, the reusability and storage stability of catalase@HSN also are satisfactory. This proposed strategy provides a facile method for preparing biocatalysts under mild conditions, facilitating the applications of immobilized enzyme in the fields of real biocatalytic industry with high apparent activity and passable stability. A new state of highly active enzymes has been established through soft template removal method to construct enzyme contained hollow silica nanosphere (enzyme@HSN) biocatalysts where enzymes in the cavity exhibit "immobilized but not rigid state". [Display omitted] • Hybrid MOF using glutathione as alternative ligand was used as self-sacrificial template for hollow silica fabrication. • Enzyme molecules in hollow silica nanosphere are "Immobilized but Not Rigid State" with improved activity. • This proposed strategy provides a facile method for preparing nano-biocatalysts under mild conditions. [ABSTRACT FROM AUTHOR]

We herein evaluated the impact of adding wheat bran dietary fiber (WBDF) on the aggregation behavior of gluten in dough at various stages of the noodle-making process. Scanning electron microscopy and confocal laser scanning microscopy images confirmed the effective insertion of WBDF particles into the gluten matrix. Importantly, the gap between WBDF and gluten widened during the rolling process. The addition of WBDF led to a reduction in glutenin macropolymer (GMP) content and an elevation in sulfhydryl content, induced the depolymerization behaviors at the molecular level. Additionally, it facilitated the conversion of α-helices and β-turns into β-sheets and random coils within the dough. Moreover, the processing and addition of WBDF contributed to a decrease in weight loss, whereas the degradation temperature remained constant. Resting decreased the sulfhydryl content, whereas sheeting and cutting increased it, further fostering protein depolymerization in the presence of WBDF. These actions significantly increased the β-sheets and random coils content at the expense of β-turns and α-helices content. Significantly, controlled processing emerged as a crucial factor in enhancing gluten depolymerization induced by WBDF in the dough. This comprehensive study provides a nuanced perspective on controlling dough processing to strike a balance between dietary fiber-rich and high-quality foods. • GMP revealed that WBDF addition level had more influence than noodle-making process. • WBDF, and sheeting and cutting induced the transformation of α-helix and β-turn into β-sheet and random coil structure. • Resting resulted in a more uniform gluten network. • WBDF and processing had a synergistic effect on the gluten aggregation behavior of the dough. [ABSTRACT FROM AUTHOR]

In this study, cinnamic acid (CA) conjugated hydroxypropyl chitosan (HPCS) derivatives (HPCS-CA) with different degrees of substitution (DS) were successfully synthesized. The reaction was divided into two steps: the first step was to modify chitosan (CS) to HPCS, and the second step was to graft CA onto HPCS. Structural characterization and properties were carried out employing elemental analysis, Fourier transform infrared (FT–IR) spectroscopy, ultraviolet–visible (UV–vis) spectroscopy, nuclear magnetic resonance (NMR) spectra, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The solubility test revealed the better water solubility of derivatives than CS. In addition, in vitro antibacterial and antibiofilm tests were performed. As expected, HPCS-CA derivatives exhibited good antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The MIC and MBC of HPCS-CA derivatives could reach 256 μg/mL and 512 μg/mL, respectively. Confocal laser scanning microscopy (CLSM) analysis proved the inhibitory effect of HPCS-CA derivatives on S. aureus and E. coli biofilms by disrupting the formation of biofilms, reducing the thickness of biofilms, and the number of live bacteria. These results suggest the potential applicability of HPCS-CA derivatives in the treatment of biofilm-associated infections and provide a practical strategy for the design of novel CS-based antibacterial materials. • HPCS-CA derivatives with different degree of substitution were synthesized through amide reaction. • FT–IR, NMR, and UV–vis revealed that HPCS-CA derivatives were successfully synthesized. • HPCS-CA derivatives exhibited good antibacterial and antibiofilm properties compared to CS and HPCS. • HPCS-CA derivatives provide a practical strategy for the design of novel chitosan antibacterial materials. [ABSTRACT FROM AUTHOR]

A cellulose nanocrystal based oxidation system is developed for oxidizing starch in the presence of NaClO, and provides an alternative and green method to improve the oxidizing degree of oxidized starch. The underlying mechanism for the oxidation was studied with confocal laser scanning microscopy. It was found that cellulose nanocrystal would penetrate into the starch microparticles and contribute to oxidation. The function of cellulose nanocrystal on the physicochemical properties of oxidized starch was investigated. With the incorporation of the oxidized starch into starch/polyvinyl alcohol/glyceryl composite films, the mechanical property and transparency of the films improved substantially. The highest oxidation level of starch was attained at 0.5 wt% cellulose nanocrystal dosage and the carboxylate content was 1.10%, the composite film showed the maximum transparency of 0.66 and highest contact angle of 102.0°. Meanwhile, the best film was obtained with oxidized starch containing 1.0 wt% cellulose nanocrystal. Compared to native starch and TEMPO-oxidated starch, the cellulose nanocrystal-based oxidized starch improved the hydrophobicity of film more substanially. In conclusion, cellulose nanocrystal acts as prooxidant and reforcing agent in this starch-based composite film, which makes them promising materials in the preparation of novel composite materials. [Display omitted] [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of hydrothermal treatments (heat-moisture treatment (HMT) and annealing (ANN)) on the physicochemical properties and in vitro digestibility of yam starch and yam flour. Hydrothermal treatments decreased the pasting properties of yam starch and yam flour. Compared with yam starch, HMT significantly (p < 0.05) reduced the pasting viscosities of yam flour. Both HMT and ANN caused an increase of the gelatinization temperatures (T o , T p , and T c) and a decrease of enthalpy (△H). The increasement in ratio of 1047/1022 cm−1 and 995/1022 cm−1 suggested that HMT and ANN resulted in an increase in short-range order. The crystalline pattern of all samples was still A-type, and HMT yam starch exhibited higher crystallinity (26.20%). The most significant inhibition of in vitro digestibility was found in HMT yam flour, with slowly digestible starch and resistant starch contents increasing by 3.73% and 4.40%, respectively. Hydrothermal treatments made the no-starch ingredients in yam flour agglomerate and adhere to starch granules. Confocal laser scanning microscopy showed that the starch being coated or embedded by protein was a possible reason for the differences in physicochemical properties and in vitro digestibility between yam starch and yam flour. [ABSTRACT FROM AUTHOR]

A food-grade emulsion gel was stabilized using waxy maize starch (WS) incorporated (−)-epigallocatechin-3-gallate (EGCG) at different ratio (from 5 % to 20 %, w/w). The microstructure, rheological behavior, physical stability and antioxidant activity of emulsion gels were investigated using confocal laser scanning microscopy (CLSM), cryo-scanning electron microscopy (cryo-SEM), and rheometer, etc. The results suggested that incorporated EGCG obviously affected the spatial configuration of WS hydrogel. The WS/EGCG hydrogels presented an excellent lipophilic capacity characterized by tightly adhering to linseed oil droplets in the emulsion gels. Moreover, the viscosity, viscoelasticity and physical stability of the emulsion gels stabilized by the WS/EGCG hydrogel matrices were significantly enhanced. The emulsion gel stabilized by the WS/EGCG hydrogel matrix (15 % EGCG) had long-term emulsifying stability because its emulsified phase volume fraction (77.14 %) remained stable for 30 days. Compared with typical natural and synthetic antioxidants in food and pharmaceutical processing, the emulsion gels stabilized by the WS/EGCG hydrogel matrices showed significant stronger DPPH (97.45 %) and ABTS•+ (97.97 %) free radical scavenging activity. These results demonstrate that WS/EGCG hydrogels can not only be used in food-grade matrix materials to stabilize emulsion gels but also improve the antioxidant activity of the emulsion gels. [Display omitted] • Addition of EGCG has visible effect on microstructure of waxy starch hydrogel. • WS-EGCG interactions endow the starch hydrogel with lipophilicity. • WS/EGCG hydrogels can absorb on the surface of oil droplets as stabilizers. • WS/EGCG hydrogel can form an orderly network structure on emulsion droplets. [ABSTRACT FROM AUTHOR]

The effect of acidification through hydrochloric acid combined with inulin (In), and inulin/sodium alginate (In/SA) on the stability of native/thermally denatured myofibrillar proteins (MPs/TMPs) particles in an aqueous system was investigated. At the same pH, MPs-In and TMPs-In particles were smaller and had higher absolute potentials than MPs-In/SA and TMPs-In/SA particles. Additionally, the size of MPs-In particles reached 1 μm, and the solubility increased from 21.73 ± 0.57 % to 76.26 ± 1.27 % when the pH was reduced from 5.0 to 3.0. The absolute potential of TMPs 3-In particles increased from 15.77 ± 0.72 to 28.20 ± 0.30 mV, and the solubility increased from 18.65 ± 0.72 % to 74.53 ± 0.74 %. Confocal laser microscopy revealed that, compared with pH 5.0 or 4.0, MPs-In/TMPs-In particles dispersed more evenly at pH 3.0 compared with pH 5.0 or 4.0. This further confirmed that electrostatic repulsion between particles maximally contributed to particle stability. Furthermore, the α-helix content in TMPs-In particles at pH 3.0 decreased from 41.51 ± 1.09 % (TMPs control) to 16.61 ± 1.87 %. This decrement of an up to 60 % led to decreased intramolecular hydrogen bonds and improved surface hydrophobicity. Therefore, a single polysaccharide (In) combined with MPs/TMPs particles exhibited higher dispersion and stability at pH 3.0. These findings could provide new insights into chicken-derived protein beverage processing. • The solubility of MPs-In particles was 76.26 % at pH 3.0 and 8.96 % at pH 5.0. • The main particle size of MPs combined with inulin was as low as 1 μm at pH 3.0. • The hydrophobicity of MPs/TMPs particles was enhanced by adding a polysaccharide. • α-helix content of TMPs-In reduced more sharply with lowered pH than MPs-In. • The dispersion and stability of MPs-In were better than that of MPs-In/SA at pH 3.0. [ABSTRACT FROM AUTHOR]

A food-grade emulsion gel was stabilized using waxy maize starch (WS) incorporated (−)-epigallocatechin-3-gallate (EGCG) at different ratio (from 5 % to 20 %, w/w). The microstructure, rheological behavior, physical stability and antioxidant activity of emulsion gels were investigated using confocal laser scanning microscopy (CLSM), cryo-scanning electron microscopy (cryo-SEM), and rheometer, etc. The results suggested that incorporated EGCG obviously affected the spatial configuration of WS hydrogel. The WS/EGCG hydrogels presented an excellent lipophilic capacity characterized by tightly adhering to linseed oil droplets in the emulsion gels. Moreover, the viscosity, viscoelasticity and physical stability of the emulsion gels stabilized by the WS/EGCG hydrogel matrices were significantly enhanced. The emulsion gel stabilized by the WS/EGCG hydrogel matrix (15 % EGCG) had long-term emulsifying stability because its emulsified phase volume fraction (77.14 %) remained stable for 30 days. Compared with typical natural and synthetic antioxidants in food and pharmaceutical processing, the emulsion gels stabilized by the WS/EGCG hydrogel matrices showed significant stronger DPPH (97.45 %) and ABTS•+ (97.97 %) free radical scavenging activity. These results demonstrate that WS/EGCG hydrogels can not only be used in food-grade matrix materials to stabilize emulsion gels but also improve the antioxidant activity of the emulsion gels. [Display omitted] • Addition of EGCG has visible effect on microstructure of waxy starch hydrogel. • WS-EGCG interactions endow the starch hydrogel with lipophilicity. • WS/EGCG hydrogels can absorb on the surface of oil droplets as stabilizers. • WS/EGCG hydrogel can form an orderly network structure on emulsion droplets. [ABSTRACT FROM AUTHOR]

In the present study, we prepared cinnamaldehyde (CA) conjugated chitosan-stabilized emulsions (CSCAEs), and the influence of pH on their properties and lipolysis behavior was investigated. Compared to the emulsions stabilized by chitosan itself (CSEs), CSCAEs had better stability against pH during storage. As pH increased from 2.5 to 6.25, the viscosity and modulus of CSCAEs increased. However, when pH shifted from 6.25 to 6.5, emulsion showed lower viscosity and modulus. Confocal laser scanning microscopy results demonstrated that oil droplets still kept intact and individually distributed, and chitosan homogenously covered on the oil droplets at low pH conditions (pH 2.5, 4.0). At higher pH conditions (pH 5.0, 5.5), a few chitosan aggregates on the oil droplets were observed. At pH 6.0 and 6.25, the compact gel network structure was formed. At pH 6.5, some void was found among the chitosan gel network. In vitro simulated digestion experiments presented that pH had no significant effect on the lipolysis process of emulsions. When the oil content varied from 10% to 50%, emulsions still kept good stability against pHs, but the lipolysis extent after digestion decreased. This knowledge provides a strategy for improving stability of chitosan-stabilized emulsion against harsh pH conditions. • Cinnamaldehyde conjugated chitosan emulsions had good stability against pH. • The absorption and desorption of chitosan could be controlled by pH. • Rheological properties of emulsions were modulated by pH. • Lipolysis behavior of emulsions depended on the pH condition and oil content. [ABSTRACT FROM AUTHOR]

Fluorescent nanoprobe with good water dispersibility was synthesized by the coupling of fluorescent 1,8-naphthalimide dye (NANI) as well as biocompatible poly (ethylene glycol) (PEG) to cellulose nanocrystals (CNC). FTIR, TGA and XPS analysis confirmed the successful covalent conjugation of NANI and PEG. The rod-like morphology of CNC was generally retained after two-step successive grafting of NANI and PEG. The contact angle and transmittance measurements showed that the grafted PEG brushes improve the hydrophilicity of fluorescent CNC probes and their dispersibility in high-concentration NaCl solutions. The fluorescent CNC probe had good biocompatibility and was successfully used for the bioimaging of Hela cells in physiological environment at high salt concentration. Laser confocal microscopy showed that the fluorescent CNC probe can penetrate the cell membrane and disperse uniformly in the cell with good biocompatibility. The fluorescent CNC probe with nanometer size, strong fluorescence emission and high salt-tolerance possess potential application in biomedical field. Poly(ethylene glycol)-grafted fluorescent cellulose nanocrystals were synthesized by two-step EDC/NHS-mediated coupling reaction. The fluorescent cellulose nanocrystals possessed good water-dispersibility and biocompatibility, which further improved the bioimaging performance of Hela cells. Unlabelled Image • Fluorescent dye and poly(ethylene glycol) were covalently conjugated to cellulose nanocrystals. • Good fluorescence property and water dispersibility at high salt concentration were achieved. • The fluorescent cellulose nanocrystals were successfully used for the bioimaging of Hela cells. [ABSTRACT FROM AUTHOR]

Redox-responsive theranostic nanoparticles based on poly-(N -ε-carbobenzyloxy- l -lysine) (PZLL) grafted hyaluronan (HA) (HA-g-SS-PZLL) copolymers were constructed for hepatocellular carcinoma diagnosis and therapy. These hyaluronan derivatives formed nanoparticles via a self-assembly process in aqueous solution at low concentration. Theranostic nanoparticles were obtained after loading hydrophobic doxorubicin (DOX) and superparamagnetic iron oxide (SPIO) into the core of the nanoparticles via a dialysis method. Theranostic nanoparticles exhibited redox triggered DOX release behavior, and faster DOX released from theranostic nanoparticles was detected under a reducing environment compared with slow DOX release under a normal physiological environment. Confocal laser scanning microscopy (CLSM), flow cytometry and Prussian blue staining against HepG2 cells demonstrated that HA-g-SS-PZLL theranostic nanoparticles were capable of delivering DOX and SPIO into the cells. The analysis of the anticancer effect revealed that the HA-g-SS-PZLL theranostic nanoparticles shown higher cytotoxicity against HepG2 cells than DOX-loaded HA-g-PZLL nanoparticles. In vitro T 2 magnetic resonance imaging (MRI) results exhibited that theranostic nanoparticles showed a good contrast enhancement effect, and the r 2 relaxivity value was approximately 231 Fe mM−1 s−1. Finally, the theranostic nanoparticles acted as nanoprobes for HepG2 tumor-bearing BALB/c mice for in vivo MRI. Therefore, HA-g-SS-PZLL copolymers have great potential as theranostic nanoparticles for tumor-targeted diagnosis and treatment. [ABSTRACT FROM AUTHOR]

The surfactant-free nature and higher stability of Pickering emulsions make them preferable solutions over conventional emulsions for skin applications. In this work, Pickering emulsions stabilized by chitosan/gum Arabic (CH/GA) nanoparticles were tested as vehicles for trans-resveratrol topical delivery. Skin absorption was examined ex vivo using Franz diffusion cells and porcine skin. Pickering emulsions allowed higher cutaneous retention and lower permeation of resveratrol, in comparison with a control solution based on a 20% v/v ethanol. The total amount of resveratrol retained in the skin, 24 h after the application, was 11.60% and 10.82% of the applied dose for the tested Pickering emulsion-based formulations prepared with 0.5% and 1.5% w/v CH/GA nanoparticles, respectively. In contrast, resveratrol skin retention from the control solution was only 2.86%. Confocal laser scanning microscopy revealed enhanced skin deposition of Nile Red to deeper layers from the Pickering emulsion-based formulations. Moreover, Pickering emulsions led to trans-resveratrol photostability increase, as measured after exposure to UV for 4 h. These results show that the CH/GA Pickering emulsions are promising solutions for the topical delivery of trans-resveratrol and have the potential to be used as green cosmetic products. Unlabelled Image • Stable RSV-loaded chitosan/gum Arabic Pickering emulsions were developed. • Topical delivery of RSV from Pickering emulsions was assessed for the first time. • Entrapment of RSV in Pickering emulsions enhanced its retention in the skin. • Chitosan/gum Arabic Pickering emulsions improved the photostability of RSV. [ABSTRACT FROM AUTHOR]

Surface modification of multiwalled carbon nanotubes (MWCNTs) could enhance the features of the nanomaterial as carrier for enzyme immobilization. In this strategy, magnetic MWCNTs were fabricated by incorporating them with cobalt and functionalization was carried out by aminated polydopamine. The surface modified MWCNTs were then used as a carrier for the immobilization of Candida rugosa lipase (CRL) via covalent binding using glutaraldehyde. The immobilized CRL maintained high activity, which was 3-folds of free CRL. The immobilized CRL exhibited excellent thermal resistance as validated by TGA and DTA technique and was found to be active in a broad range of pH and temperatures in comparison to free CRL. Systematic characterization via FT-IR spectroscopy, CD spectroscopy, SEM, TEM and confocal laser scanning microscopy confirmed the presence of CRL on the modified MWCNTs. Immobilized CRL presented an exquisite recycling performance as after ten consecutive reuses it retained around 84% of its initial hydrolytic activity and further showed high yield enzymatic synthesis of ethyl butyrate and isoamyl acetate having characteristic pineapple and banana flavour demonstrating 78% and 75% ester yield, respectively. The present work provides a novel perspective for lipase catalyzed biotechnological applications by adding a magnetic gain to intrinsic features of MWCNTs. • Modified MWCNT NC immobilized CRL resulted in 3 fold activity stimulation. • Immobilized CRL exhibited excellent operational stability. • CRL immobilization was affirmed by CLSM, TEM, SEM, FT-IR and CD spectroscopy. • AGM affirmed the magnetic behaviour of the as-synthesized NC. • CRL#PDA@Co-MWCNT resulted in high yield enzymatic synthesis of fruit flavours. [ABSTRACT FROM AUTHOR]

Although noticeable scientific and technological progress, cancer remains one of the deadliest diseases worldwide and advancements in diagnosis, targeting and treating cancer cells are an urgency. In this study, we designed and synthesized novel amino acid and polypeptide modified polysaccharide derivatives associated with fluorescent nanomaterials for producing nanohybrids with functionalities for bioimaging and cell penetrating. Carboxymethylcellulose (CMCel) was chemically biofunctionalized with L-cysteine (CMCelCys) or poly-L-arginine (CMCelPolyArg) and the conjugates were used as capping ligands for synthesizing fluorescent AgInS 2 quantum dots (AIS-QDs) in aqueous colloidal media. These systems were characterized by FTIR, NMR, UV–Vis, TEM-EDX, DLS, zeta potential and PL for assessing physicochemical properties, structural and morphological features. Mitochondrial activity assay (MTT) was used for evaluating preliminary cytotoxicity and confocal laser microscopy for investigating cellular uptake of the nanohybrids. Results confirmed the biofunctionalization of CMCel through amide bonds formation and indicated the formation of water-dispersed fluorescent nanocolloids with core-shell nanostructures composed by semiconductor cores stabilized by shell layers of CMCelCys or CMCelPolyArg. The nanohybrids' optical properties were affected by the grafting of functionalities into CMCel. All nanohybrids demonstrated no in vitro cytotoxicity based on MTT results and were successfully internalized by glioma cells, behaving as fluorescent nanoprobes for bioimaging and biolabeling. Unlabelled Image • Novel "green" fluorescent polysaccharide-AIS QD nanobioconjugates were developed. • Core-shell nanostructures were functionalized with L-cysteine and poly-L-arginine. • AIS-carboxymethylcellulose colloids were formed and functionalized in aqueous media. • The nontoxic nanoconjugates behaved as active fluorescent nanoprobes for bioimaging. • The nanoconjugates can be applied as fluorescent nanoplatforms for cancer research. [ABSTRACT FROM AUTHOR]

Reduced-fat food has become a popular choice among contemporary consumers. This study aims to develop a starch-based fat substitute and incorporate it into reduced-fat milk gel acidified with glucono-δ-lactone (GDL) to achieve similar rheological properties as a full-fat gel. The gel properties of the fat substitute were assessed. The study examined the rheological properties, syneresis, textural properties and microstructure of acidified milk gels while also monitoring acidification process. Starch hydrolysates with low dextrose equivalent (DE) (<5.1 %) can serve as an effective fat substitute due to their excellent gelling properties The rheological and textural properties of the reduced-fat acidified milk gel with DE at 3.1 % of starch hydrolysate and 30 % fat substitution are similar to those of the full-fat milk gel. The syneresis and confocal laser scanning microscopy (CLSM) results indicated that the microstructure of the reduced-fat acidified milk gel was similar to the full-fat version. Moreover, the sensory properties of the reduced-fat acidified milk gel were acceptable when the DE was 3.1 %, and 30 % fat was replaced. In our study, we utilized hydrolyzed starch to produce reduced-fat acidified milk gels, which could potentially be used in the development of reduced-fat yogurt formulations. [ABSTRACT FROM AUTHOR]

This study investigated the morphology distribution, molecular structure, and aggregative properties variation of gluten protein during dough mixing stage and interpreted the interaction between starch with different sizes and protein. Research results indicated that mixing process induced glutenin macropolymer depolymerization, and promoted the monomeric protein conversion into the polymeric protein. Appropriate mixing (9 min) enhanced the interaction between wheat starch with different particle sizes and gluten protein. Confocal laser scanning microscopy images showed that a moderate increase in B-starch content in the dough system contributed to forming a more continuous, dense, and ordered gluten network. The 50A-50B and 25A-75B doughs mixed for 9 min exhibited a dense gluten network, and the arrangement of A-/B-starch granules and gluten was tight and ordered. The addition of B-starch increased α-helixes, β-turns, and random coil structure. Farinographic properties indicated that 25A-75B composite flour had the highest dough stability time and the lowest degree of softening. The 25A-75B noodle displayed maximum hardness, cohesiveness, chewiness, and tensile strength. The correlation analysis indicated that starch particle size distribution could influence noodle quality by changing the gluten network. The paper can provide theoretical support for regulating dough characteristics by adjusting the starch granule size distribution. • B-starch contributed to forming a more continuous, dense and ordered gluten network. • B-starch could increase the GMP content, stabilize gluten network during mixing. • The 25A-75B flour had maximum dough stability time and the lowest degree of softening. • Model depicting the interaction between A-/B-starch and gluten was established. [ABSTRACT FROM AUTHOR]

The interactions of fish gelatine (FG) with hyaluronic acid (HA) are studied in an aqueous environment at 25 °C by turbidimetric titration, confocal scanning laser microscopy, dynamic light scattering, zeta potentiometry, spectrophotometry with methylene blue, and construction of state diagrams. FG forms soluble complexes with HA above a boundary pH (pH φ1 ), where both biopolymers are net-negatively charged, but develop insoluble complexes as liquid-state complex coacervates below pH φ1 , where the two biopolymers are oppositely charged. The insoluble complexes are continuously aggregated with further acid titration, followed by immediate visible phase-separation when another boundary pH (pH p ) is reached. The complex formation is mainly driven by electrostatic attractions rather than hydrogen bonding or hydrophobic interactions. The complex formation is promoted by increasing FG-to-HA weight ratio or total biopolymer concentration, or at a low ionic strength, but significantly suppressed in the presence of high ionic strength. [ABSTRACT FROM AUTHOR]

In this study, a novel nanofiber material with Polylactic acid (PLA), natural plant polysaccharides- Bletilla striata polysaccharide (BSP) and Rosmarinic acid (RA) as the raw materials to facilitate wound healing was well prepared through coaxial electrospinning. The morphology of RA-BSP-PVA@PLA nanofibers was characterized through scanning electron microscopy (SEM), and the successful formation of core-shell structure was verified under confocal laser microscopy (CLSM) and Fourier transform infrared spectroscopy (FTIR). RA-BSP-PVA@PLA exhibited suitable air permeability for wound healing, as indicated by the result of the water vapor permeability (WVTR) study. The results of tension test results indicated the RA-BSP-PVA@PLA nanofiber exhibited excellent flexibility and better accommodates wounds. Moreover, the biocompatibility of RA-BSP-PVA@PLA was examined through MTT assay. Lastly, RA-BSP-PVA@PLA nanofibers can induce wound tissue growth, as verified by the rat dorsal skin wound models and tissue sections. Furthermore, RA-BSP-PVA@PLA can facilitate the proliferation and transformation of early wound macrophages, and down-regulate MPO+ expression of on the wound, thus facilitating wound healing, as confirmed by the result of immunohistochemical. Thus, RA-BSP-PVA@PLA nanofibers show great potential as wound dressings in wound healing. [ABSTRACT FROM AUTHOR]

The myofibrillar protein (MP) degradation and in vitro digestive properties of porcine longissimus during freezing at −8, −18, −25 and − 40 °C for 1, 3, 6, 9 and 12 months were investigated. As the freezing temperature and duration of frozen storage increased, the amino nitrogen and TCA (trichloroacetic acid)-soluble peptides of the samples were significantly increased, while the total sulfhydryl content and band intensity of myosin heavy chain, actin, troponin T, tropomyosin were significantly decreased (P < 0.05). At higher freezing storage temperatures and durations, the particle size of MP samples and the green fluorescent spots detected using a laser particle size analyzer and confocal laser scanning microscopy became large. After 12 months of freezing, the digestibility and the degree of hydrolysis of the trypsin digestion solution of the samples frozen at −8 °C were significantly decreased by 15.02 % and 14.28 %, respectively, when compared to fresh samples, whereas, the mean surface diameter (d 3,2) and mean volume diameter (d 4,3) were significantly increased by 14.97 % and 21.53 %, respectively. Therefore, frozen storage induced protein degradation and impaired the ability of digestion in the pork proteins. This phenomenon was more evident as the samples were frozen at high temperatures over a long storage period. • Changes in protein degradation and in vitro digestive properties were induced by freezing. • Frozen storage induced protein degradation and impaired the pork protein digestion ability. • Higher freezing temperatures and durations aggravated protein degradation. [ABSTRACT FROM AUTHOR]