Pickering emulsions synergistically stabilized by sugar beet pectin and montmorillonite exhibit enhanced storage stability and viscoelasticity

Influences of different ultrasonic treatment intensities on the molecular chain conformation and interfacial behavior of sugar beet pectin

In this study, the effects of different ultrasonic treatment intensities (57, 170, and 283 W/cm2) on the chemical composition, molecular chain characteristics, crystal structure, micromorphology, interfacial adsorption behavior and emulsifying properties of sugar beet pectin (SBP) were investigated. Ultrasonic treatment did not change the types of SBP monosaccharides, but it had impacts on their various monosaccharide contents. Moreover, the feruloylated, acetyl, and methoxy groups of SBP also undergo varying degrees of changes. The increase in ultrasonic treatment intensity led to transition in the molecular chain conformation of SBP from rigid semi-flexible chains to flexible chains, accompanied by modification in its crystal structure. Microstructural analysis of SBP confirmed the significant change in molecular chain conformation. Modified SBP could form an elastic interfacial film with higher deformation resistance on the oil-water interface. The SBP sample modified with 170 W/cm2 exhibited better emulsifying properties owing to its better interfacial adsorption behavior. Moreover, the emulsions prepared with modified SBP exhibited better stability capability under different environmental stresses (pH value, salt ion concentration, heating temperature and freeze-thaw treatment). The results revealed that the ultrasonic technology is useful to improve the emulsifying properties of SBP.

Preparation and characterization of pectin-alginate-based microbeads reinforced by nano montmorillonite filler for probiotics encapsulation: Improving viability and colonic colonization

Hydrogel microbeads can be used to enhance the stability of probiotics during gastrointestinal delivery and storage. In this study, the pectin-alginate hydrogel was enhanced by adding montmorillonite filler to produce microbeads for encapsulating Lactobacillus kefiranofaciens (LK). Results showed that the viscosity of biopolymer solutions with 1 % (PAMT1) and 3 % (PAMT3) montmorillonite addition was suitable for producing regular-shaped microbeads. A layered cross-linked network was formed on the surface of PAMT3 microbeads through electrostatic interaction between pectin-alginate and montmorillonite filler, and the surrounding LK with adsorbed montmorillonite was encapsulated inside the microbeads. PAMT3 microbeads reduced the loss of viability of LK when passing through the gastric acid environment, and facilitated the slow release of LK in the intestine and colonic colonization. The maximum decrease in viability among all filler groups was 1.21 log CFU/g after two weeks of storage, while PAMT3 freeze-drying microbeads only decreased by 0.46 log CFU/g, indicating that the gel layer synergized with the adsorbed layer to provide dual protection for probiotics. Therefore, filler-reinforced microbeads are a promising bulk encapsulation carrier with great potential for the protection and delivery of probiotics and can be developed as food additives for dairy products.

The soybean lecithin-cyclodextrin-vitamin E complex nanoparticles stabilized Pickering emulsions for the delivery of β-carotene: Physicochemical properties and in vitro digestion

In this work, soybean lecithin (LC) was used to modify β-cyclodextrin (β-CD) with hydrophobic fat chains to become amphiphilic (LC-CD), and vitamin E (VE) was encapsulated in former modified β-CD complexes (LC-CD-VE), the new Pickering emulsions stabilized by LC-CD-VE and LC-CD complexes for the delivery of β-carotene (BC) were created. The surface tension, contact angle, zeta potential, and particle size were used to assess the changes in complexes nanoparticles at various pH values. Furthermore, LC-CD-VE has more promise as Pickering emulsion stabilizer than LC-CD because of the smaller particle size (271.11 nm), proper contact angle (58.02°), and lower surface tension (42.49 mN/m). The interactions between β-cyclodextrin, soybean lecithin, and vitamin E were confirmed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and thermogravimetric analysis (TGA). The durability of Pickering emulsions was examined at various volume fractions of the oil phase and concentrations of nanoparticles. Compared to the emulsion stabilized by LC-CD, the one stabilized by LC-CD-VE showed superior storage stability. Moreover, for the delivery of BC, Pickering emulsions stabilized by LC-CD and LC-CD-VE can outperform bulk oil and Tween 80 stabilized emulsions in terms of UV light stability, storage stability, and bioaccessibility. This work could offer fresh perspectives on stabilizer alternatives for Pickering emulsion delivery systems.

Pickering emulsion with high freeze-thaw stability stabilized by xanthan gum/lysozyme nanoparticles and konjac glucomannan

In this study, freeze-thaw cycle experiments were conducted on food-grade Pickering emulsions co-stabilized with konjac glucomannan (KGM) and xanthan gum/lysozyme nanoparticles (XG/Ly NPs). The rheological properties, particle size, flocculation degree (FD), coalescence degree (CD), centrifugal stability, Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and microstructure of Pickering emulsion stabilized by KGM before and after freeze-thaw were characterized. It was found that as the concentration of KGM increased, the flocculation degree (FD) and coalescence degree (CD) of the emulsion decreased after the freeze-thaw cycle compared to the control sample, and the microscopic images showed that the droplets became smaller and less affected by the freeze-thaw cycles. The rheological and water-holding properties also confirmed that the KGM-added emulsions still had a strong gel network structure and prevented the separation of the continuous and dispersed phases of the droplets after freezing and thawing. Freeze-thaw treatments had a negative effect on the stable emulsion of XG/Ly NPs, while the addition of KGM improved the freeze-thaw stability of the emulsion, which provided a theoretical basis for the development of emulsion products with high freeze-thaw stability.