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In this study, anthocyanin-loaded water 1 -in-oil-in-water 2 (W 1 /O/W 2 ) double Pickering emulsions stabilized by octenylsuccinate quinoa starch (OSQS) were optimized, and their storage stability and in vitro gastrointestinal digestion were evaluated. Novel starch-based double emulsions as anthocyanin cargos were achieved at 2% (w/v of oil) of polyglycerol polyricinoleate concentration, the W 1 /O volume proportion of 3:7, 6% (w/v of total volume) of OSQS concentration, and the volume proportion of (W 1 /O): W 2  = 6:4 and 5:5. CLSM results evidenced the formation of double Pickering emulsions, and the significant decreases in the encapsulation stability of anthocyanins were closely related to the increases in the droplet size induced by osmotic pressure. Less than 15% of anthocyanins in the double Pickering emulsions was released after incubated for 60 min under simulated stomach conditions; controlled-release of anthocyanins was observed during the 120 min of simulated intestinal digestion, consistent with starch hydrolysis data. These findings will be useful for designing starch-based double Pickering emulsion with intestinal-targeted delivery as a novel carrier of sensitive hydrophilic bioactive compounds., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Lutein is essential for infant visual and cognitive development but has low stability and solubility. This study aimed to enhance the stability and bioaccessibility of lutein using oil-in-water emulsions stabilized with biopolymers. Commercially available octenylsuccinylated (OS) starches, including capsule TA® (CTA), HI-CAP®100 (HC), and Purity Gum® 2000 (PG), along with gum Arabic (GA) variants Ticaloid acacia Max® (TAM), TICAmulsion® 3020 (TM), and pre-hydrate gum Arabic (PHGA), were chosen as emulsifiers. By screening the effect of biopolymer concentration and oil volume fraction (Φ), emulsions stabilized with CTA, HC, or TM at 20% and 30% (w / v) concentration and 70% Φ exhibited a gel-like structure and were selected for further assessments. After a week at 25 °C, emulsions stabilized by CTA and HC showed no significant change in droplet size, while TM emulsion exhibited a 1.58-fold increase. At 45 °C, all emulsions exhibited increase in droplet size. Lutein retention is higher in CTA emulsions at both storage temperatures than free lutein. In vitro bioaccessibility of all lutein emulsions was higher than that of free lutein. These findings highlight the superior stability and bioaccessibility of the lutein emulsion stabilized by OS starch, positioning it as a promising carrier to broaden lutein applications in infant foods. [ABSTRACT FROM AUTHOR]

Abstract The development of emulsion gels has attracted increasing interests due to their potential applications as oil structuring templates and release-controlled carriers for sensitive lipid-soluble bioactive compounds. This work aimed to elucidate the importance of changing the degree of substitution (DS, 0.0072–0.0286) and oil volume fraction (Φ, 10–90%) to achieve octenylsuccinate (OS) quinoa starch granule-based Pickering emulsion gels. The gelation process, droplet size distribution, rheological properties and microstructure of Pickering emulsion gels formed at various DS and Φ values were evaluated. Octenylsuccinylation did not change the morphology or the granule size of quinoa starch but significantly increased the contact angle from 36.2° to 68.7°. OS quinoa starch granule-stabilized Pickering emulsion gels were formed at a DS of 0.0286 with Φ values ranging from 50 to 70%. At the Φ value of 70%, increasing DS progressively increased the apparent viscosity (η) and storage modulus (G′) of the emulsions as a result of the adsorption of more OS quinoa starch granules at the oil/water interface. Both η and G′ showed an increasing trend as a function of Φ (50–70%) at a DS value of 0.0286, and this was closely related to the microstructure of the formed emulsion gels. The network of OS quinoa starch-based Pickering emulsion gels at high Φ values (e.g., 60% and 70%) was mainly composed of compact "aggregated" oil droplets, which was largely attributed to the inter-droplet interactions. These results are of great help in understanding the gelling mechanism and the development of starch granule-based Pickering emulsion gels. Graphical abstract Image 1054545 Highlights • OSA modification enabled the efficient adsorption of quinoa starch at the oil/water interface. • Increasing oil volume fraction enhanced the extent of aggregation of oil droplets. • Inter-droplet interaction was responsible for the formation of Pickering emulsion gels. [ABSTRACT FROM AUTHOR]

Hydrophobic modified starch nanoparticles were fabricated through combined starch nanoprecipitation and complexation with zein, and their emulsifying behaviors were further evaluated as a Pickering emulsion stabilizer. Novel starch/zein nanocomposites with a unimodal particle distribution, mean diameter of 147.9 nm and contact angle of 83.0° were achieved. Fourier transform-infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, differential scanning calorimetry, and confocal laser scanning microscopy demonstrated that the zein was successfully complexed with the starch molecules. Dissociation test confirmed that electrostatic interaction and hydrogen bonding were the main driving forces for the formation and maintenance of the starch/zein nanocomposites. Complexing with zein endowed the starch nanoparticles with emulsion pH-responsive behavior, which could provide a simple and green pathway to pH-responsive materials that afford controlled release of bioactive ingredients with emulsion delivery and recyclable catalysis of enzymatic reactions. Image 1 • Novel starch/zein nanocomposites were successfully fabricated. • Complexation with zein achieved hydrophobic modification of starch. • Starch/zein ratio and reverse method dominated the formation of nanocomposites. • Starch/zein nanocomposites exhibited emulsion pH-responsive behavior. [ABSTRACT FROM AUTHOR]

Octenylsuccinate quinoa starch (OSQS) granule that stabilized Pickering emulsion gel with different gel networks by modulating the oil volume fraction (Φ) was developed as a carrier for lutein. Pickering emulsion gels stabilized by OSQS were achieved at Φ values ranging from 30% to 60%. Increasing Φ progressively increased the droplet size, storage modulus, and apparent viscosity, resulting in the formation of gel-like structure. Confocal laser scanning microscopy showed that OSQS formed a densely packed layer at the oil/water interface, the degree of aggregation between droplets increased, and the gel network enhanced through droplet flocculation with increasing Φ. After 31 days of storage, the retention index of lutein in the emulsion gel could reach 55.38%, and the corresponding half-life times increased from 12 to 41 days. This study will be useful for designing starch-based Pickering emulsion gel with tunable gel network and desirable characteristics as delivery carrier of sensitive bioactive compounds. • Oil volume fraction modulated the gel network of starch-based emulsion gel. • Bridged droplets should be responsible for the formation of emulsion gel. • Compact gel network conferred superior storage stability to lutein. [ABSTRACT FROM AUTHOR]

Emulsion electrospinning emerges as a promising technique for producing core-shell nanofibers used in delivering bioactive compounds. This work aims to investigate the feasibility of employing octenylsuccinylated (OS) starch-based emulsions in electrospinning for the fabrication of these nanofibers. The influence of sunflower seed oil concentration, ranging from 5% to 50%, on the emulsions was systematically examined. Increasing the oil concentration affects several key characteristics of the emulsions. These changes include a rise in apparent viscosity (from 0.78 to 7.72 Pa·s at 100 s−1) and average droplet size (from 1.21 to 1.79 μm), as well as a decrease in conductivity (from 727 to 193 μs/cm), leading to a larger average diameter of electrospun fibers, which increased from 294 to 533 nm. Confocal laser scanning microscopy and transmission electron microscopy confirmed the core–shell structure of the fibers. Furthermore, the correlation between fiber size and emulsion properties was discussed, and it was noted that the average fiber diameter, loading capacity, and encapsulation efficiency were significantly affected by emulsion composition and properties. These insights contribute to our understanding of the emulsion electrospinning process and offer a valuable guidance for the development of OS starch-based core–shell electrospun fibers. [Display omitted] • Electrospinning of emulsions stabilized by OS starch and pullulan was studied. • Oil content significantly affected emulsions stability and average fiber diameter. • The core–shell structure of the fibers was confirmed by CLSM and TEM. • Loading capacity and encapsulation efficiency were affected by emulsion properties. [ABSTRACT FROM AUTHOR]

In this study, lycopene-loaded nanofibers were successfully fabricated by electrospinning of oil-in-water (O/W) emulsions stabilized by whey protein isolate-polysaccharide TLH-3 (WPI–TLH-3) complexes. The lycopene encapsulated in the emulsion-based nanofibers exhibited enhanced photostability and thermostability, and achieved improved targeted small intestine-specific release. The release of lycopene from the nanofibers followed Fickian diffusion mechanism in simulated gastric fluid (SGF) and first-order model in simulated intestinal fluid (SIF) with the enhanced release rates. The bioaccessibility and cellular uptake efficiency of lycopene in micelles by Caco-2 cells after in vitro digestion were significantly improved. The intestinal membrane permeability and transmembrane transport efficiency of lycopene in micelles across Caco-2 cells monolayer were greatly elevated, thus promoting the effective absorption and intracellular antioxidant activity of lycopene. This work opens a potential approach for electrospinning of emulsions stabilized by protein–polysaccharide complexes as a novel delivery system for liposoluble nutrients with enhanced bioavailability in functional food industries. • Fabrication of lycopene-loaded nanofibers by electrospinning of O/W emulsions • Lycopene encapsulated exhibited enhanced photostability and thermostability. • The targeted small intestine-specific release of lycopene was achieved. • The bioaccessibility and cellular uptake efficiency of lycopene were improved. • The transport efficiency of lycopene across Caco-2 cells monolayer was elevated. [ABSTRACT FROM AUTHOR]