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•Oxidized dextrans (ODex) with different aldehyde group contents are prepared.•ODex is used as a green cross-linking agent for gelatin to obtain hydrogels.•A high content of aldehyde ...groups leads to an enhanced degree of cross-linking.•The composite hydrogels are thermally stable with excellent mechanical properties.•Adjustment of the hydrogel characteristics allows the controlled release of curcumin.
Controlled drug delivery could minimize side effects while maintaining a high local dose. Herein, a hydrogel carrier was prepared by forming dynamic imine bonds between gelatin and oxidized dextran (ODex) of different molecular weights (Mw = 10, 70, and 150 kDa). The morphology, thermal stability, rheology, mechanical properties, and swelling properties of the hydrogels and the controlled release of curcumin were characterized. When dextran with a higher Mw was used, the ODex contained more aldehyde groups, which led to a higher degree of cross-linking, considerably shorter gel time, decreased hydrogel porosity, and well-controlled release of curcumin. In addition, the cross-linked hydrogels exhibited not only high thermal stability but also excellent mechanical properties. However, because the matrix was hydrophilic, the swelling properties of the hydrogels were not significantly affected by the Mw of ODex. These observations suggest an approach for designing nutrient delivery carriers with improved controlled release.
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•The protein–phenolic compound conjugates are prepared by three methods.•The structures and antioxidant properties of these conjugates were investigated.•The physical stabilities and ...oxidation properties of their emulsions were examined.•The conjugates prepared via one of the methods slowed lipid and protein oxidation.•The conjugates prepared via the other two methods promoted protein oxidation.
Oil-in-water emulsions are widely used in the food industry; however, lipids are often easily oxidized, which may adversely affect food quality. Herein, we investigated the effects of alkali treatment, free radical induction, and carbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS)-mediated synthetic methods on the structures and antioxidant properties of soy protein isolate (SPI)–gallic acid (GA) conjugates and the physical stabilities and protein–lipid co-oxidation properties of the resulting emulsions. These three methods are well established; however, their effects on the same protein–phenolic compound system have not been directly compared. Additionally, the co-oxidation of proteins and oils in emulsions remains unexplored. Alkali treatment yielded superior antioxidant properties compared to those obtained using free radicals or EDC/NHS, as this method was more likely to yield CS bonds and resulted in an increased quantity of grafted GA. Spectroscopic analysis showed that alkali treatment promoted GA oxidation and thereby increased GA-protein interactions and the quenching of tryptophan fluorescence. Correspondingly, EDC/NHS-mediated conjugation retained the activity of the hydroxyl groups of GA to the largest extent. Moreover, the grafting of GA improved the physical and oxidative stabilities of the emulsions. In particular, EDC/NHS-mediated conjugation produced an emulsion with optimal oxidative stability owing to its effective inhibition of lipid and protein oxidation. Conversely, the conjugates synthesized via alkali treatment and free radical induction displayed less inhibition of lipid oxidation and promoted protein oxidation. In conclusion, optimized protein–phenolic compound conjugates for use in developing nutritional fortification products with longer shelf lives can be obtained by using appropriate synthetic methods.
Comparison between oxidized hydrogen-substituted graphyne (O-HsGY) and graphene oxide (GO) on adsorption and electrochemical properties were studied as well as the possible mechanisms were discussed ...on the effects of modification by deep eutectic solvents (DESs)/ionic liquids (ILs) and composition with multi-walled carbon nanotubes oxide (O-MWCNT). And the effects of DESs and ILs for GO and O-HsGY were compared. The electrical conductivity of the modification materials by DESs/ILs were improved and the aggregation of GO was prevented to some extent. The specific surface area and pore size of composite materials were larger, which could provide more active sites for the electrolyte ions and genotoxic impurities for adsorption/desorption and diffusion. Due to the different extent of expanded interlayer space after modification and better dispersity in solution, the GO-related materials have better adsorption and electrochemical capacitance properties compared with O-HsGY-related materials. There was much inductive affection of groups in DES3 which can effectively inhibit the stacking of GO sheets. And DES3-GO showed good adsorption performance for three types of aniline genotoxic impurities with the adsorption performance of 12.21 mg g
−1
, 8.11 mg g
−1
and 15.98 mg g
−1
by static adsorption experiment, respectively. The larger surface area and pore size were obtained for the composites modified by IL and the oxidation of GO was reduced to a greater extent which improved the conductivity of GO. And the specific capacitance of 130.57 F g
−1
was obtained for IL2-GO/O-MWCNT at the current density of 1.5 A g
−1
.
Graphical Abstract
This study aimed to identify the most suitable delivery system for quercetin. To achieve this objective, four delivery systems, i.e., coarse emulsions, nano-emulsions, high internal phase emulsions ...(HIPEs), and emulsion gels, were prepared and characterized by structure, rheology, stability, and bioaccessibility. The nano-emulsion exhibited the smallest particle size, highest absolute ζ-potential, and best thermal stability and storage stability. The HIPEs showed the best freeze-thaw and oxidative stability. Regarding rheology, all delivery systems exhibited elastic gel-like behavior, which consistent to the characteristics of non-Newtonian fluids. The encapsulation efficiencies of quercetin in these delivery systems were greater than 81.56%. The lowest rate of free fatty acid release was observed in the HIPEs, and the highest bioaccessibilities of quercetin were observed in the nano-emulsion and emulsion gel. Thus, the nano-emulsion is the most suitable for the delivery of quercetin among the four delivery systems.
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•Coarse emulsion, nano-emulsion, HIPEs, and emulsion gel were fabricated.•The encapsulation efficiency of quercetin in these delivery systems was >81.56%.•HIPEs decreased the release rate of FFA during in vitro simulated digestion.•The nano-emulsion and emulsion gel exhibited the highest bioaccessibilities.•The nano-emulsion was the most suitable for the delivery of quercetin.
In this study, oil-in-water emulsions were co-stabilized by a soy protein isolate-(−)-epigallocatechin gallate (SPI-EGCG) conjugate, tea saponin (TS), and hexadecyltrimethylammonium bromide (CTAB) ...(0.01–1.00%, w/v), and the influence of the mixed SPI-EGCG-conjugate–surfactant interface on the physical stability and protein–lipid co-oxidation properties of each emulsions was investigated. Our results demonstrated that TS exhibits a better emulsifying ability than CTAB by significantly reducing interfacial tension; this emulsion contained the smallest particles at a TS concentration of 1.0% (w/v). In addition, the interfacial protein content revealed the existence of synergistic (CTAB) and competitive (TS) adsorption between the protein and surfactant. The presence of TS displaced protein molecules at the interface and inhibited protein oxidation, which reveals that proteins adsorbed at the oil–water interface are more sensitive to oxidation than unadsorbed proteins. The degrees of protein and lipid oxidation were enhanced in the presence of CTAB. Furthermore, the addition of TS delayed lipid oxidation; this phenomenon was most pronounced at a TS concentration of 1.0% (w/v). Our results indicate that combining SPI-EGCG conjugates with TS provides an optimal design for the development of nutritionally fortified products with longer shelf lives.
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•Effects of the surfactant concentration and type on the emulsions were investigated.•TS gave the best emulsification ability and effective interfacial tension reduction.•The co-oxidation of proteins and lipids occurred depending on the protein location.
Spray-drying can stabilize high-moisture-content oil bodies (OBs) against adverse environmental conditions and improve the nutritional value of foods containing OBs. This study investigates the ...effect of the dextrose equivalent (DE) of maltodextrin (MD) on the physicochemical properties and oxidative stability of soybean OB microcapsules during spray-drying. Adding MD to OB microcapsules reduced the surface-oil content and improved the drying yield and encapsulation efficiency. Microcapsules produced by MD having a DE of 10 (MD 10) returned the highest microencapsulation yield (88.84 g/100 g) and efficiency (93.41 g/100 g). OBs stabilized by MD 10 (OB-MD 10) also exhibited optimal water content, water activity, reconstitutability, hygroscopicity, density, and flowability. The addition of MD 10 reduced the size and narrowed the size distribution of microcapsules, thereby reducing agglomeration. Furthermore, MD 10 produced a more effective interfacial barrier, thereby improving the thermal and oxidative stability of the microencapsulated OBs, which can be explained by the molecular structure of the carrier. MD 10 was found to be the most effective wall material for stabilizing OBs. This work establishes spray-drying as a promising method for the industrial production and application of OBs as functional oil products that can carry biologically active ingredients.
•Soybean oil bodies (OBs) were encapsulated using maltodextrin (MD) by spray-drying.•MD-encapsulated OBs were more-stable than spray-dried free OBs.•MD increased the thermal and oxidative stability of OB microcapsules.•MD with dextrose equivalent of 10 (MD 10) produced the most stable OB microcapsules.
•Heat-induced SPH gels comprised basic B polypeptide in 11S and β subunits in 7S.•Ultrasound enhanced the hardness of SPH gels at pH 3–9.•Ultrasound increased ionic and hydrogen bonds of SPH gels at ...pH 7–9.•SPH gel treated by pH 7 + ultrasound exhibited the superior gelation characteristics.
This study aimed to evaluate the gelation characteristics of soybean protein hydrolysate (SPH) extracted by enzyme-assisted aqueous extraction. Specifically, the changes in gelation behaviors for heat-induced (95 °C, 20 min) SPH dispersions treated with pH (pH 3, 5, 9; pH 7 as control) and ultrasound (U; 240 W, 30 min) were investigated. The results showed that typical gel behavior with high elastic nature in the viscoelasticity and network structures were observed during the heating process, where the disulfide bond played a dominant role in the gel network formation of all the samples. Notably, the heat-induced aggregation in the SPH gels was mainly formed by the association of the basic B polypeptide in 11S and β subunit in 7S. The most superior SPH gel was formed at pH 7 when assisted by ultrasonication during the heating process. This as-synthesized gel showed a uniform filamentous structure and exhibited the more excellent textural, rheological and thermal properties than those of the samples formed under acidic and alkaline conditions. These results are of great value in revealing the gelation mechanism of SPH.
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•Complex formation of SPI with dextran dialdehyde (ODex) via Schiff base reaction.•A novel biopolymer-based nanoparticle delivery system for curcumin was developed.•The thermal and ...storage stability of nanocomplex was improved by ODex.•The nanocomplex has excellent antioxidant properties.•Controlled release properties of curcumin improved by ODex.
Dextran dialdehyde (ODex) was added to a nanocomplex of soy protein isolate (SPI)-curcumin (Cur) to improve its stability and achieve controlled release of Cur. The SPI-to-ODex mass ratio was optimized to achieve excellent properties and stability. Interactions between various components were confirmed by spectroscopic analysis, and the effect of ODex on the stability and bioactivity of SPI-Cur colloids was discussed. ODex was found to be crosslinked with SPI via the Schiff base reaction, which increased the ζ-potential and improved the surface hydrophobicity of nanocomplexes. At a SPI-to-ODex mass ratio of 20:1, the nanocomplex had a smaller particle size (199.2 nm), higher ζ-potential (−45.48 mV), and higher encapsulation efficiency (96.25%). Furthermore, adding ODex changed the network structure and effectively improved the thermal and storage stability of Cur as well as its antioxidant properties. Moreover, controlled release of Cur was observed during simulated digestion in the gastrointestinal environment.
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