Pickering emulsions stabilized by chitosan-flaxseed gum-hyaluronic acid nanoparticles for controlled topical release of ferulic acid.

Chitosan (CS) based nanoparticles (NPs) were fabricated via an ionic gelation reaction modified by flaxseed gum (FG) or sodium tripolyphosphate (STPP). The average particle size, morphology, interfacial tension, and wettability of NPs were characterized. The particle size of CS-STPP-HA (hyaluronic acid)-FA (ferulic acid) NPs and CS-FG-HA-FA NPs was 400.8 nm and 262.4 nm, respectively under the optimized conditions of CS/STPP = 5:1 (w/w) or CS/FG = 1:1 (v/v) with HA concentration of 0.25 mg/mL and FA dosage of 25 µM. FG acted as a good alternative for STPP to form particles with CS in stabilizing Pickering emulsion with an internal diacylglycerol (DAG) phase of 50-80 % (v/v). The complex nanoparticles had high surface activity and contact angle close to 90 °C, being able to tightly packed at the droplet surface. The emulsions had high thermal, ionic and oxidative stability. With the aid of moisturizing polysaccharides and DAG oil, the emulsions had a good sustained-release ability for FA with deeper penetration and retention into the dermis of the skin. Thus, FG and HA-based NPs serve as green vehicles for the fabrication of novel Pickering emulsions and possess great potential to be applied as a delivery system for lipophilic active agents in functional food and cosmetic products.

Effect of Diacylglycerol Crystallization on W/O/W Emulsion Stability, Controlled Release Properties and In Vitro Digestibility.

Water-in-oil-in-water (W/O/W) emulsions with high-melting diacylglycerol (DAG) crystals incorporated in the oil droplets were fabricated and the compositions were optimized to achieve the best physical stability. The stability against osmotic pressure, encapsulation efficiency and in vitro release profiles of both water- and oil-soluble bioactives were investigated. The presence of interfacial crystallized DAG shells increased the emulsion stability by reducing the swelling and shrinkage of emulsions against osmotic pressure and heating treatment. DAG crystals located at the inner water/oil (W1/O) interface and the gelation of the inner phase by gelatin helped reduce the oil droplet size and slow down the salt release rate. The DAG and gelatin-contained double emulsion showed improved encapsulation efficiency of bioactives, especially for the epigallocatechin gallate (EGCG) during storage. The double emulsions with DAG had a lower digestion rate but higher bioaccessibility of EGCG and curcumin after in vitro digestion. DAG-stabilized double emulsions with a gelled inner phase thus can be applied as controlled delivery systems for bioactives by forming robust interfacial crystalline shells.

Interfacial behavior, gelation and foaming properties of diacylglycerols with different acyl chain lengths and isomer ratios.

Diacylglycerols (DAG) of varying chain lengths were synthesized and the acyl migrated samples with different 1,3-DAG/1,2-DAG ratios were obtained. The crystallization profile and surface adsorption differed depending on DAG structure. C12 and C14 DAGs formed small platelet- and needle-like crystals at the oil-air interface which can better reduce surface tension and pack in an ordered lamellar structure in oil. The acyl migrated DAGs with higher ratios of 1,2-DAG showed reduced crystal size and lower oil-air interfacial activity. C14 and C12 DAG oleogels exhibited higher elasticity and whipping ability with crystal shells surrounding bubbles, whereas C16 and C18 DAG oleogels had low elasticity and limited whipping ability due to the formation of aggregated needle-like crystals and loose gel network. Thus, acyl chain length dramatically influences the gelation and foaming behaviors of DAGs whereas the isomers exert little influence. This study provides basis for applying DAG of different structures in food products.

Physicochemical and In Vitro Digestion Properties of Curcumin-Loaded Solid Lipid Nanoparticles with Different Solid Lipids and Emulsifiers.

Curcumin-loaded solid lipid nanoparticles (Cur-SLN) were prepared using medium- and long chain diacylglycerol (MLCD) or glycerol tripalmitate (TP) as lipid matrix and three kinds of surfactants including Tween 20 (T20), quillaja saponin (SQ) and rhamnolipid (Rha). The MLCD-based SLNs had a smaller size and lower surface charge than TP-SLNs with a Cur encapsulation efficiency of 87.54-95.32% and the Rha-based SLNs exhibited a small size but low stability to pH decreases and ionic strength. Thermal analysis and X-ray diffraction results confirmed that the SLNs with different lipid cores showed varying structures, melting and crystallization profiles. The emulsifiers slightly impacted the crystal polymorphism of MLCD-SLNs but largely influenced that of TP-SLNs. Meanwhile, the polymorphism transition was less significant for MLCD-SLNs, which accounted for the better stabilization of particle size and higher encapsulation efficiency of MLCD-SLNs during storage. In vitro studies showed that emulsifier formulation greatly impacted on the Cur bioavailability, whereby T20-SLNs showed much higher digestibility and bioavailability than that of SQ- and Rha-SLNs possibly due to the difference in the interfacial composition. Mathematical modeling analysis of the membrane release further confirmed that Cur was mainly released from the intestinal phase and T20-SLNs showed a faster release rate compared with other formulations. This work contributes to a better understanding of the performance of MLCD in lipophilic compound-loaded SLNs and has important implications for the rational design of lipid nanocarriers and in instructing their application in functional food products.

Simultaneous loading of (-)-epigallocatechin gallate and ferulic acid in chitosan-based nanoparticles as effective antioxidant and potential skin-whitening agents.

Chitosan (CS) based nanoparticles simultaneously loaded with (-)-epigallocatechin gallate (EGCG) and ferulic acid (FA) were fabricated via ionic gelation method modified by sodium tripolyphosphate and genipin (G-CS-EGCG-FA NPs). The particle size, morphology, entrapment efficiency, rheological properties, antioxidant and tyrosinase inhibitory activity of NPs were investigated. The G-CS-EGCG-FA NPs exhibited irregular ellipsoidal shape with average diameter of 412.3 nm and high DPPH and ABTS·+ scavenging ability. The entrapment efficiency of EGCG and FA in NPs was 46.0 ± 1.3 % and 46.8 ± 1.6 %, respectively. CS-based NPs show no toxic effects on NIH 3 T3 cells and B16-F10 melanoma cells with concentration <200 µg/mL and 25 µg/mL, respectively and the cell viability ranged from 100 % to 118 %. Meanwhile, the oxidative repaired capacity of G-CS-EGCG-FA NPs (200 µg/mL) in H2O2-induced cells was over 100 %, higher than that of the same dose of free EGCG or FA. Moreover, the tyrosinase inhibition activity of G-CS-EGCG-FA NPs (25 µg/mL) (84.6 %) was more potent than that of free EGCG (55.3 %), free FA (47.1 %) and kojic acid, indicating the good skin repairing and whitening ability of G-CS-EGCG-FA NPs. Given these results, this research provides new insights for designing novel particles loaded with dual bioactive agents that possess synergistic benefits.

Sustainable Valorization of Litsea cubeba (Lour.) Pers. Residue as the New Lauric Oil Source Using Alternative Green Extraction and Refining Methods.

Litsea cubeba is an ethnic woody oil plant, in which essential oil rather than oil has been the main foreign trade product through the decades. Concerning large amounts of residue generated from L. cubeba essential oil processing, a sustainable valorization pathway of these biowastes is proposed in this study. First, such biowastes have been systematically investigated for the first time regarding their oils extracted by three extraction methods, where ultrasound-assisted extraction (UAE) could significantly improve the extraction rate of traditional pressing and solvent extraction without any changes in oil quality. Moreover, the composition of acylglycerols and fatty acids in L. cubeba fruit, kernel, and peel oils were also first identified, which further proved that peels with abundant free fatty acids could lead to high acid value of L. cubeba fruit oils. Compared to virgin coconut oils, L. cubeba kernel oils have a more balanced fatty acid composition with a high lauric acid level, which could be applied as a promising lauric oil resource. Considering the high acid value in L. cubeba kernel oils, both decoloration using activated clay and alkali deacidification were attempted, where the combination of alkali deacidification and 10% of activated clay performed the best considering both quality and cost.

Stabilisation of oleofoams by lauric acid and its glycerol esters.

Four types of pure lipid, namely lauric acid (LA), glycerol monolaurate (MAG), diglycerol laurate (DAG) and triglyceride laurate (TAG) were used to prepare oleofoams. The relationship between crystal profiles and their performance in oleofoams was established. DAG formed small needle-like crystals while MAG formed large flake-like crystals in oleogels, and crystal shells around air bubbles were observed in LA-, MAG- and DAG-based oleofoams. LA and DAG displayed higher over-run whereas DAG-stabilised foam possessed smaller bubbles and higher physical stability due to the presence of small ß and ß' crystals. Upon heating, DAG and TAG-based foams showed varying extents of oil drainage indicating the crystals were distributed in a different manner. Therefore, DAG was shown to be an excellent gelator in the fabrication of ultra-stable oleofoams. This work extends the lipid varieties with nutritional features and allows a better understanding on the stabilization mechanisms of lauric acid lipids in oleofoams.

W/O high internal phase emulsion featuring by interfacial crystallization of diacylglycerol and different internal compositions.

High internal phase emulsions (HIPEs) show promising application in food and cosmetic industries. In this work, diacylglycerol (DAG) was applied to fabricate water-in-oil (W/O) HIPEs. DAG-based emulsion can hold 60% water and the emulsion rigidity increased with water content, indicating the water droplets acted as "active fillers". Stable HIPE with 80% water fraction was formed through the combination of 6 wt% DAG with 1 wt% polyglycerol polyricinoleate (PGPR). The addition of 1 w% kappa (κ)-carrageenan and 0.5 M NaCl greatly reduced the droplet size and enhanced emulsion rigidity, and the interfacial tension of the internal phase was reduced. Benefiting from the Pickering crystals-stabilized interface by DAG as revealed by the microscopy and enhanced elastic modulus of emulsions with the gelation agents, the HIPEs demonstrated good retaining ability for anthocyanin and ß-carotene. This study provides insights for the development of W/O HIPEs to fabricate low-calories margarines, spread or cosmetic creams.

Tailored rigidity of W/O Pickering emulsions using diacylglycerol-based surface-active solid lipid nanoparticles.

Pickering water-in-oil (W/O) emulsions were fabricated by using medium-long chain diacylglycerol (MLCD)-based solid lipid nanoparticles (SLNs) and the connection between the characteristics of the SLNs and the colloidal stability of the emulsions was established. Via melt-emulsification and ultrasonication, MLCD-based SLNs with particle sizes of 120-300 nm were obtained with or without other surfactants. The particle size of the SLNs was influenced by the chemical properties of the surfactants, and surfactants decreased the contact angle of SLNs at the oil-water interface. Gelation was observed in SLNs modified by sodium stearoyl lactylate and lecithin, whereas the addition of Tween 20 resulted in a homogeneous SLN solution. The adsorption of surfactants onto SLN surfaces caused the production of higher amounts of α crystals accompanied by delayed crystallization onset which contributed to the reduction of particle size, interfacial tension and oil wetting ability. The W/O emulsions with higher rigidity and physical stability can be obtained by varying surfactant types and by increasing SLN mass ratios to 60%, whereby more SLNs are adsorbed at the droplet surface as a Pickering stabilizer. This study provides useful insights for the development of diacylglycerol-based SLNs and Pickering W/O emulsions which have great potential for food, cosmetic and pharmaceutical applications.

Fabrication and characterization of stable oleofoam based on medium-long chain diacylglycerol and ß-sitosterol.

Oleofoams have emerged as attractive low-calorie aeration systems, but saturated lipids or large amount of surfactants are commonly required. Herein, an innovative strategy was proposed to create oleofoams using medium-long chain diacylglycerol (MLCD) and ß-sitosterol (St). The oleofoams prepared using MLCD and St in ratios of 15:5 and 12:8 exhibited smaller bubble size and much higher stability. MLCD crystals formed rigid Pickering shell, whereby air bubbles acted as "active fillers" leading to enhanced rigidity. Both Pickering and network stabilization for the MLCD-St oleofoam provided a steric hindrance against coalescence. The gelators interacted via hydrogen bonding, causing a condensing effect in improving the gel elasticity. The oleofoams and foam-based emulsions exhibited a favorable capacity in controlling volatile release where the maximum headspace concentrations and partition coefficients showed a significantly decrease. Overall, the oleofoams have shown great potential for development of low-calorie foods and delivery systems with enhanced textural and nutritional features.

Immobilized Lipase in the Synthesis of High Purity Medium Chain Diacylglycerols Using a Bubble Column Reactor: Characterization and Application.

Novozym® 435, an immobilized lipase from Candida antarctica B. (CALB), was used as a biocatalyst for the synthesis of high purity medium chain diacylglycerol (MCD) in a bubble column reactor. In this work, the properties of the MCD produced were characterized followed by determining its practical application as an emulsifier in water-in-oil (W/O) emulsion. Two types of MCDs, namely, dicaprylin (C8-DAG) and dicaprin (C10-DAG), were prepared through enzymatic esterification using the following conditions: 5% Novozym® 435, 2.5% deionized water, 60°C for 30 min followed by purification. A single-step molecular distillation (MD) (100-140°C, 0.1 Pa, 300 rpm) was performed and comparison was made to that of a double-step purification with MD followed by silica gel column chromatography technique (MD + SGCC). Crude C8-DAG and C10-DAG with DAG concentration of 41 and 44%, respectively, were obtained via the immobilized enzyme catalyzing reaction. Post-purification via MD, the concentrations of C8-DAG and C10-DAG were increased to 80 and 83%, respectively. Both MCDs had purity of 99% after the MD + SGCC purification step. Although Novozym® 435 is a non-specific lipase, higher ratios of 1,3-DAG to 1,2-DAG were acquired. Via MD, the ratios of 1,3-DAG to 1,2-DAG in C8-DAG and C10-DAG were 5.8:1 and 7.3:1, respectively. MCDs that were purified using MD + SGCC were found to contain 1,3-DAG to 1,2-DAG ratios of 8.8:1 and 9.8:1 in C8-DAG and C10-DAG, respectively. The crystallization and melting peaks were shifted to higher temperature regions as the purity of the MCD was increased. Dense needle-like crystals were observed in MCDs with high purities. Addition of 5% C8-DAG and C10-DAG as emulsifier together in the presence of 9% of hydrogenated soybean oil produced stable W/O emulsion with particle size of 18 and 10 µm, respectively.

Effect of diacylglycerol interfacial crystallization on the physical stability of water-in-oil emulsions.

The influence of diacylglycerol (DAG) combined with polyglycerol polyricinoleate (PGPR) on the stability of water-in-oil (W/O) emulsions containing hydrogenated palm oil (HPO) was studied. Polarized light microscope revealed that DAG promoted HPO to crystallize at the water-oil interface, providing the combination of Pickering and network stabilization effects. It was proposed that the molecular compatibility of fatty acids in DAG with HPO accounted for the promotional effect. The interfacial crystallization of DAG together with the surface activity of PGPR led to the formation of emulsions with uniform small droplets and high freeze-thaw stability. Further exploration of physical properties indicated that the combination of DAG and PGPR dramatically improved the emulsion's viscoelasticity and obtained a larger deformation yield. Water droplets in DAG-based emulsions acted as active fillers to improve the network rigidity. Therefore, DAG is a promising material to be used as emulsifier to enhance the physical stability of W/O emulsions.

Non-aqueous foams formed by whipping diacylglycerol stabilized oleogel.

Formation of foams is critical for tailoring the texture and mouthfeel of fat-based products. Diacylglycerol (DAG) is regarded as a preferable alternative structurant to hydrogenated lipid. Effect of DAG concentration (2-10 wt%) on the characteristics of oleogels and foams including crystal polymorphisms, size and distribution, rheological and thermodynamic properties was investigated. Oleogel prepared with 10 wt% DAG had comparable whipping and foaming stability to that of 6 wt% fully hydrogenated palm oil (FHPO). DAG formed small plate-crystals which tend to occur at the bubble surface, whereas FHPO showed needle-like crystals that were formed mainly in the continuous phase. For the 2 wt% FHPO-8 wt% DAG-based oil foams, interfacial templating crystallization effect contributed to the smaller bubble size and improved rheological properties whereby less oil drainage and foam breakdown occurred. Hence, the non-aqueous foam formed by DAG has broad application prospect because of the thermoresponsive properties and the desirable health benefits.

Flexible and Hierarchical 3D Interconnected Silver Nanowires/Cellulosic Paper-Based Thermoelectric Sheets with Superior Electrical Conductivity and Ultrahigh Thermal Dispersion Capability.

To date, various electronic devices have been strategically fabricated, and simultaneous realization of high electrical conductivity, sensing property, and heat-conducting property by a simple, efficient, and accurate approach is significant but still challenging. Here, cellulosic fiber supported 3D interconnected silver nanowire (AgNW) networks with hierarchical structures are rationally designed to achieve excellent electrical conductivity and superior thermal dispersion capability. In particular, thermal annealing at the junctions enables both phonon and electron transfer as well as impedes interfacial slippage. In the current study, the AgNW/cellulosic paper with the low Ag content (1.55 wt %) exhibits a low sheet resistance of 0.51 Ω sq-1. More importantly, the AgNW/cellulosic paper-based flexible strain sensor has been reasonably developed, which can be applied to monitor various microstructural changes and human motions with high sensitivity and robust stability (fast response/relaxation time of ∼100 ms and high stability >2000 bending-stretching cycles). The AgNW/cellulosic paper-based device also displays efficient thermal dispersion property, which offers exciting opportunities for thermal management application. Furthermore, the obtained hybrid paper exhibits superior heat dispersion capacity for thermal management devices. Overall, uniform dispersion and 3D interconnected junctions of AgNW among the fibers inside the cellulosic papers lead to the combination of high mechanical strength, highly efficient electrical conductivity, and ultrahigh heat dispersion property. The AgNW/cellulosic paper has promising potentials in the flexible and wearable sensing elements, thermal management materials, and artificial intelligence devices.

Fabrication and Characterization of Oleogel Stabilized by Gelatin-Polyphenol-Polysaccharides Nanocomplexes.

The development of oleogel has attracted growing attention because of its health benefits and promising potential to substitute saturated or trans-fat. The present work reports a type of oleogel using the emulsion stabilized by gelatin (GLT), tannic acid (TA), and flaxseed gum (FG) complexes (GLT-TA-FG) through freeze-drying and oven-drying. Results showed that the incorporation of TA and FG promoted the formation of nanoparticles, resulting in increased charge quantity and reduced oil-water surface tension. The structural integrity of oleogel largely depends on the drying method, FG incorporation, and TA concentration. It was demonstrated that with oven drying, stable oleogel without oil leakage could only be fabricated in the presence of FG. The GLT-0.075 wt % TA-FG complexes formed a particle shell around the oil droplet, leading to the enhanced gel strength of the oleogel. In addition, the oleogel stabilized by GLT-TA-FG complexes had high thixotropic recovery degree and rehydration ability, implying the stabilizing effect of TA and FG. Therefore, the interfacially adsorbed particles and the polymer gel network in bulk together contributed to the compact structure of oleogel. We believe that the oleogel based on GLT-TA-FG complexes has potential applications in food products with tunable rheological and textural properties.

Effect of malondialdehyde modification on the binding of aroma compounds to soy protein isolates.

The interactions of soy protein isolate (SPI) and flavor compounds (hexanal, trans-2-hexenal, 1-octen-3-ol, trans-2-octenal, nonanal, and trans-2-nonenal) were investigated. The influence of SPI structure modified by malondialdehyde (MDA) and flavor compound structure on the interactions were determined by using headspace solid-phase microextraction (SPME) and gas chromatography (GC) combined with mass spectrometry (MS). The binding of native SPI to the flavor compounds decreased in the order trans-2-nonenal>nonanal>trans-2-octenal>trans-2-hexenal>hexanal>1-octen-3-ol. It might be attributed to that aldehydes are more hydrophobic than alcohols. The former is more conducive to hydrophobic binding with the SPI. Furthermore, the aldehydes, in particular trans-s-undecenal, could also react covalently. The effect of MDA modification on protein-flavor interactions depended on the structure of the flavor compound. Upon low concentration of MDA (≤1mM), the binding of all six flavors to SPI increased. However, a further increase in the extent of MDA (≥2.5mM), more soluble and even insoluble aggregates formed, which reduced the binding of hexanal and nonanal to SPI. The other four flavors with double bond revealed little changes in binding (trans-2-octenal, and trans-2-nonenal) or even an increase in binding (trans-2-hexenal, and 1-octen-3-ol). The results suggested that hydrophobic interactions were weakened upon high extent of oxidation, whereas covalent interactions were enhanced.

Additional band broadening of peptides in the first size-exclusion chromatographic dimension of an automated stop-flow two-dimensional high performance liquid chromatography.

The need to improve the peak capacity of liquid chromatography motivates the development of two-dimensional analysis systems. This paper presented a fully automated stop-flow two-dimensional liquid chromatography system with size exclusion chromatography followed by reversed phase liquid chromatography (SEC×RPLC) to efficiently separate peptides. The effects of different stop-flow operational parameters (stop-flow time, peak parking position, number of stop-flow periods and column temperature) on band broadening in the first dimension (1st D) SEC column were quantitatively evaluated by using commercial small proteins and peptides. Results showed that the effects of peak parking position and the number of stop-flow periods on band broadening were relatively small. Unlike stop-flow analysis of large molecules with a long running time, additional band broadening was evidently observed for small molecule analytes due to the relatively high effective diffusion coefficient (Deff). Therefore, shorter analysis time and lower 1st D column temperature were suggested for analyzing small molecules. The stop-flow two-dimensional liquid chromatography (2D-LC) system was further tested on peanut peptides and an evidently improved resolution was observed for both stop-flow heart-cutting and comprehensive 2D-LC analysis (in spite of additional band broadening in SEC). The stop-flow SEC×RPLC, especially heart-cutting analysis with shorter analysis time and higher 1st D resolution for selected fractions, offers a promising approach for efficient analysis of complex samples.

Self-assembled colloidal complexes of polyphenol-gelatin and their stabilizing effects on emulsions.

This research studies the in-depth characteristics including the binding interactions and morphological structure of tannic acid (TA)/grape seed proanthocyanidins (GSP) and gelatin (GLT) colloidal complexes, and evaluated the stability and lipid oxidation of emulsions formed by the colloidal complexes. Polyphenol and GLT (1.2 wt%) self-assembled complexes were fabricated by varying the mass ratio (1 : 16, 1 : 8 and 1 : 4) and pH in the range of 3-7. TA and GSP can form stable colloidal complexes with GLT at the nanoscale at pH 6, as shown by the particle size results, and the complexes exhibited a spherical morphology as seen by transmission electron microscopy. Hydrogen bonding was the main binding force for the interaction between polyphenols and GLT. The antioxidant activity of GLT was greatly improved after complexing with polyphenols. The oil/water emulsion formed by the complexes had a smaller droplet size and higher lipid oxidation stability during storage. This was largely due to the physical barrier formed by polyphenol-GLT colloidal complexes at the oil-water interface, which can prevent the pro-oxidant from penetrating into oil. These results clarified the structural, morphological and antioxidant properties of polyphenol-gelatin non-covalent complexes, which is of great value for their application in food solutions as well as in emulsion systems.

The influence of ionic strength on the characteristics of heat-induced soy protein aggregate nanoparticles and the freeze-thaw stability of the resultant Pickering emulsions.

The improvement of the freeze-thaw stability of emulsions by interfacial engineering has attracted increasing attention in recent years. The present work investigated the potential of using soy protein isolate (SPI) aggregate nanoparticles as the Pickering stabilizers to improve the freeze-thaw stability of the resultant emulsions. SPI nanoparticles with different particle sizes and surface properties were fabricated through heating the SPI solutions (at a constant protein concentration of 2%, w/v) at 95 °C for 15 min, by varying the ionic strength (I) in the range of 0-500 mM. The nanoparticles fabricated at I values of 100-500 mM exhibited larger particle sizes and higher surface hydrophobicity, but poorer emulsification efficiency than those at I = 0.05 mM. The presence of NaCl during the nanoparticle fabrication resulted in the formation of a kind of gel-like emulsion with a high extent of droplet flocculation. The emulsion stabilized by SPI nanoparticles at I = 0.05 mM was highly susceptible to coalescence, flocculation and creaming upon freeze-thaw treatment, while those in the presence of NaCl exhibited excellent freeze-thaw stability. The much better freeze-thaw stability of the emulsions in the presence of NaCl (relative to that at I = 0.05 mM) was largely attributed to the gel-like network formation, rather than the salt itself. The results indicated that a kind of Pickering emulsion with excellent freeze-thaw stability, stabilized by heat-induced SPI nanoparticles, could be fabricated by heating the SPI solutions at I values of 100-500 mM. The findings would be of great relevance for providing important information about the development of food grade Pickering emulsions stabilized by protein-based particles, with potential applications in frozen food, or functional food formulations.

Influence of glycosylation of deamidated wheat gliadin on its interaction mechanism with resveratrol.

Gliadin is a main composition of wheat storage protein with unique characteristics. Polyphenol with health benefits tends to form complex with protein. In this study, glycosylation of deamidated wheat gliadin (gliadin) was carried out. Fluorescence quenching was applied to evaluate their binding mechanisms with resveratrol. Results showed that glycosylation could increase the solubility and decrease the surface hydrophobicity of gliadin. Both gliadin and glycosylated gliadin have strong affinity with resveratrol. The thermodynamic parameters of binding process indicated that complexation of resveratrol with gliadin was mainly driven by hydrophobic interaction, while by hydrogen bonds with glycosylated gliadin. The hydrosolubility of resveratrol was dramatically increased especially in the presence of glycosylated gliadin. This was consistent with the higher binding constant of glycosylated gliadin with resveratrol. Therefore, gliadin and glycosylated gliadin are both effective to carry resveratrol or other bioactive compounds, and their binding mechanisms are different due to structural difference.