Novel Bilayer Emulsions Costabilized by Zein Colloidal Particles and Propylene Glycol Alginate. 2. Influence of Environmental Stresses on Stability and Rheological Properties

Casein/butyrylated dextrin nanoparticles and chitosan stabilized bilayer emulsions as fat substitutes in sponge cakes

This study aimed to evaluate the potential of the bilayer emulsions stabilized with casein/butyrylated dextrin nanoparticles and chitosan as fat substitutes in preparing low-calorie sponge cakes. Among the different cake groups, the substitution of bilayer emulsions at 60% exhibited comparable baking properties, appearance, texture characteristics and stable secondary structure to fat. The specific volume and height were increased by 36.94% and 22%, respectively, while the cake showed higher lightness (L*) in the cores and softer hardness in the crumb. In addition, the moisture content of cakes was increased while the water activity remained unchanged. These results showed that casein/butyrylated dextrin bilayer emulsion was a potential fat substitute for cake products at the ratio of 60% with the desirable characteristics.

Zein and tannic acid hybrid particles improving physical stability, controlled release properties, and antimicrobial activity of cinnamon essential oil loaded Pickering emulsions

Pickering emulsion loading essential oil has demonstrated a promising strategy as delivery system in food preservation, but localization in stability and antimicrobial activity limits application. In this study, Pickering emulsions co-loaded with tannic acid and cinnamon essential oil (ZTC) have been developed based on zein and tannic acid complexes (ZT) mediated interfacial engineering. Fourier transform infrared, fluorescence spectroscopy, and molecular docking results indicated tannic acid altered the structural of zein. Interfacial tension results indicated that tannic acid accelerated the adsorbed speed of zein particles by decreased interfacial tension (11.99-9.96 mN/m). ZT5 formed a viscoelastic and dense layer in oil-water interface than that for other ZTs, which improved stability and control release performance of ZTC. Furthermore, the ZTC showed an effective antimicrobial activity against spoilage organisms Pseudomonad paralactis MN10 and Lactobacillus sakei VMR17. These findings provide new insight for developing co-loaded multiple antimicrobial agents within Pickering emulsion as a delivery system.

Artificial oil bodies: A review on composition, properties, biotechnological applications, and improvement methods

In order to simulate the structure of natural oil body, artificial oil bodies (AOBs) are fabricated by the integration of oleosins, triacylglycerols (TAGs) and phospholipids (PLs) in vitro. Recently, AOBs have gained great research interest both in the food and biological fields due to its ability to act as a novel delivery system for bioactive compounds and as a carrier for target proteins. This review aims to summarize the composition and the preparation methods of AOBs, examine the factors influencing their stability. Moreover, this contribution focusses on exploring the application of AOBs to encapsulate functional ingredients that are prone to oxidation as well as improve efficiency involved in protein purification, renaturation and immobilization by reducing the complex steps. In addition, the improvement measures to further enhance the stability and efficacy of AOBs are also discussed. The application of AOBs is expected to be a big step towards replacing existing bioreactors and delivery systems.

Effects of nitrogen fertilizer on the physicochemical, structural, functional, thermal, and rheological properties of mung bean (Vigna radiata) protein

Nitrogen fertilizer can affect the seed quality of mung bean. However, the effects of nitrogen fertilizer on the properties of mung bean protein (MBP) remain unclear. We investigated the effects of four nitrogen fertilization levels on the physicochemical, structural, functional, thermal, and rheological properties of MBP. The results showed that the amino acid and protein contents of mung bean flour were maximized under 90 kg ha-1 of applied nitrogen treatment. Nitrogen fertilization can alter the secondary and tertiary structure of MBP. The main manifestations are an increase in the proportion of β-sheet, the exposure of more chromophores and hydrophobic groups, and the formation of loose porous aggregates. These changes improved the solubility, oil absorption capacity, emulsion activity, and foaming stability of MBP. Meanwhile, Thermodynamic and rheological analyses showed that the thermal stability, apparent viscosity, and gel elasticity of MBP were all increased under nitrogen fertilizer treatment. Correlation analysis showed that protein properties are closely related to changes in structure. In conclusion, nitrogen fertilization can improve the protein properties of MBP by modulating the structure of protein molecules. This study provides a theoretical basis for the optimization of mung bean cultivation and the further development of high-quality mung bean protein foods.

Characterization of Nanoemulsions Stabilized with Different Emulsifiers and Their Encapsulation Efficiency for Oregano Essential Oil: Tween 80, Soybean Protein Isolate, Tea Saponin, and Soy Lecithin

The use of the appropriate emulsifier is essential for forming a stable nanoemulsion delivery system that can maintain the sustained release of its contents. Health concerns have prompted the search for natural biopolymers to replace traditional synthetic substances as emulsifiers. In this study, an oregano essential oil (OEO) nanoemulsion-embedding system was created using soybean protein isolate (SPI), tea saponin (TS), and soy lecithin (SL) as natural emulsifiers and then compared to a system created using a synthetic emulsifier (Tween 80). The results showed that 4% Tween 80, 1% SPI, 2% TS, and 4% SL were the optimal conditions. Subsequently, the influence of emulsifier type on nanoemulsion stability was evaluated. The results revealed that among all the nanoemulsions, the TS nanoemulsion exhibited excellent centrifugal stability, storage stability, and oxidative stability and maintained high stability and encapsulation efficiency, even under relatively extreme environmental conditions. The good stability of the TS nanoemulsion may be due to the strong electrostatic repulsion generated by TS molecules, which contain hydroxyl groups, sapogenins, and saccharides in their structures. Overall, the natural emulsifiers used in our study can form homogeneous nanoemulsions, but their effectiveness and stability differ considerably.

Parameter control, characterization and stability of soy protein emulsion prepared by microfluidic technology

A flow-focusing microfluidic device driven by pressure was employed in soy protein emulsions with uniform droplet size and good morphology. The results suggested that pressure was an essential factor for droplet formation. The optimum parameter was at a continuous phase pressure of 140 mbar and dispersed phase pressure of 80 mbar. Under this condition, the droplet formation time was shortened to 0.20 s, with average sizes of 39-43 μm and coefficient of variation of about 2 %. Emulsion stability was improved with increasing soy protein isolate (SPI) concentrations. At SPI concentrations higher than 20 mg/mL, the emulsions exhibited improved stability against changes in temperature, pH and salt concentration. Emulsions prepared in this manner exhibited superior oxidative stability than those prepared by conventional methods utilizing homogenizers. This study showed that microfluidic technology can be applied to soy protein emulsions as an effective tool for preparing droplets with uniform size and enhanced stability.

Effects of high acyl gellan gum on the rheological properties, stability, and salt ion stress of sodium caseinate emulsion

Sodium caseinate (SC) is widely used as a biological macromolecular emulsifier in oil-in-water (O/W) emulsions. However, the SC-stabilized emulsions were unstable. High-acyl gellan gum (HA) is an anionic macromolecular polysaccharide that improves emulsion stability. This study aimed to investigate the effects of HA addition on the stability and rheological properties of SC-stabilized emulsions. Study results revealed that HA concentrations >0.1 % could increase Turbiscan stability, reduce the volume average particle size, and increase the zeta-potential absolute value of the SC-stabilized emulsions. In addition, HA increased the triple-phase contact angle of SC, transformed SC-stabilized emulsions into non-Newtonian fluids, and effectively inhibited the movement of emulsion droplets. The effect of 0.125 % HA concentration was the most effective, allowing SC-stabilized emulsions to maintain good kinetic stability over a 30-d period. NaCl destabilized SC-stabilized emulsions but had no significant effect on HA-SC emulsions. In summary, HA concentration had a significant effect on the stability of SC-stabilized emulsions. HA altered the rheological properties and reduced creaming and coalescence by forming a three-dimensional network structure, increasing the electrostatic repulsion of the emulsion and the adsorption capacity of SC at the oil-water interface, and thereby improving the stability of SC-stabilized emulsions during storage and in the presence of NaCl.

Protein-polysaccharides based nanoparticles for loading with Malus baccata polyphenols and their digestibility in vitro

The poor solubility, instability and low absorption rate obstruct the bioavailability of polyphenols isolated from Malus baccata (MBP) during gastrointestinal digestion. In order to solve the limitable problems, the food-grade nanoparticles were fabricated by mucin (MC) and Hohenbuehelia serotina polysaccharides (HSP) for delivery of MBP (MBP-NPs). The physicochemical properties and morphology of MBP-NPs prepared by different condition were respectively characterized. During gastrointestinal digestion in vitro, the release characteristic and variation in phenolic composition of MBP-NPs were evaluated. The results showed that MBP-NPs formed by hydrogen bonding and hydrophobic interaction possessed the regularly spherical shapes and smooth surfaces and semi-crystalline properties. Moreover, MBP-NPs presented the excellent physicochemical stability. During simulated gastrointestinal digestion in vitro, MBP-NPs exhibited the sustained release characteristics of phenolic compounds, which were confirmed by SDS-PAGE measurement. Compared with that of unencapsulated MBP, the significant variation was occurred in the phenolic composition of MBP-NPs, indicating that MBP-NPs could prevent the degradation and transformation of phenolic compounds. This study provides a novel strategy to improve the bioavailability of polyphenols.

Extraction of structurally intact and well-stabilized rice bran oil bodies as natural pre-emulsified O/W emulsions and investigation of their rheological properties and components interaction

The isolated plant oil bodies (OBs) have shown promising applications as natural pre-emulsified O/W emulsions. Rice bran OBs can be used as a new type plant-based resource with superior fatty acids composition and abundant γ-oryzanol. This paper investigated the method of extracting structurally intact and stable rice bran OBs. Due to the adequate steric hindrance and electrostatic repulsion effects, rice bran OBs extracted by NaHCO₃ medium had smaller particle size, better physical stability, and natural structure. The protein profile of NaHCO₃-extracted rice bran OBs showed oleosin-L and oleosin-H, while exogenous proteins in PBS and enzyme-assisted- extracted rice bran OBs could interact with interfacial proteins through hydrophobic forces to aggregate adjacent OBs, further remodeling the OBs interface. It was also found that the small-sized rice bran OBs could adsorb on the interface of the larger-sized rice bran OBs like Pickering stabilizers. Rice bran OBs exhibited pseudoplastic fluids characteristic, but underwent a transition from solid-like to liquid-like behavior depending on the extraction method. The disorder of NaHCO₃-extracted rice bran OBs protein molecules increased their surface hydrophobicity. The random coil structure favored more proteins adsorption at the interface of rice bran OBs extracted by PBS. Enzyme-assisted extraction of rice bran OBs had the highest content of β-sheet structure, which facilitated the stretching and aggregation of protein spatial structure. It was also confirmed the hydrogen bonding and hydrophobic interaction between the triacylglycerol or phospholipid and proteins molecules, and the membrane compositions of rice bran OBs differed between extraction methods.

Effect of emulsification methods on the physicochemical properties of emulsion stabilized by calcium carbonate and sodium alginate

Our lab’s studies have found that heavy calcium carbonate (CaCO₃) with sodium alginate (SA) can synergistically stabilize Pickering emulsion. However, there were significant differences in the flow characteristics of the emulsions obtained by different preparation methods during storage. Herein, in this current work, Pickering emulsions were prepared by two-step emulsifying method (SA was added into the primary emulsion stabilized by CaCO₃ for secondary shearing, M1) and one-step emulsifying method (oil phase was added to homogeneous dispersed CaCO₃-SA solution for one-step shearing, M2), respectively. The particle size, microstructure, rheology and microrheological properties of these two kinds of emulsions and the interaction of CaCO₃ with SA were analyzed. The results showed that the droplet size of M1 emulsion was 21.78–49.62 μm, and that of M2 emulsion was 6.50–11.87 μm. M1 emulsion had stronger viscoelasticity, and could transform into a gel state during storage. However, M2 emulsion remained in flow condition all the time which was related to the interaction between SA and CaCO₃ in the aqueous phase.

Oppositely Charged Pickering Emulsion Co-Stabilized by Chitin Nanoparticles and Fucoidan: Influence of Environmental Stresses on Stability and Antioxidant Activity

Single emulsifiers exhibit varying degrees of restriction in stabilizing emulsions. Oppositely charged chitin nanoparticles and fucoidan complex particles were used as emulsifiers to stabilize a o/w Pickering emulsion and explore its stability and antioxidant activity under different environmental stresses. The results showed that the emulsion with the smallest mean particle size (1.02 μm) and strongest zeta potential (−29.3 mV) was formed at pH 7. Moreover, at this pH, it presented the highest physical stability and antioxidant activity and the lowest emulsion creaming index. The investigation of the effect of temperature on the stability and antioxidant activity of the emulsion revealed that, after freezing/thawing at −20 °C, the emulsion was unstable, the particle size increased, and the stability and antioxidant activity were low. In contrast, the emulsions treated at 25, 37, and 60 °C displayed no significant differences and exhibited high stabilities and antioxidant activities. Additionally, increasing the salt ion concentration further decreased the emulsion stability and antioxidant activity. Particularly, the emulsion with a salt concentration of 500 mM displayed the lowest stability, and stratification occurred after 30 d of storage. The Pickering emulsion remained stable under different environmental stresses expect for at a temperature of −20 °C and 500 mM salt ion concentration.

Emulsions co-stabilized by soy protein nanoparticles and tea saponin: Physical stability, rheological properties, oxidative stability, and lipid digestion

Herein, the effects of the concentration (0.1%-1.0%, w/v) and addition sequence of tea saponin (TS) on the physical stability, oxidative stability, rheological properties, and in vitro digestion of the emulsions stabilized by heat-induced soy protein isolate nanoparticles (SPs) were investigated. The results revealed that the concentration and addition sequence of TS have significant impact on the microstructure, stability, rheological properties, and in vitro digestion of the emulsions. TS was shown to not only fill the interfacial gaps but also adsorb on the particle surfaces, contributing to interfacial wettability. With increasing TS concentration, interfacial tension decay is clearly observed. Further, TS endows the droplets with electrostatic repulsion and steric resistance, preventing their flocculation, coalescence, and oxidation. Finally, in vitro digestion experiments demonstrated that the presence of TS delayed the lipid digestion of the emulsions.

Delivery of Curcumin Using Zein-Gum Arabic-Tannic Acid Composite Particles: Fabrication, Characterization, and in vitro Release Properties

The application of curcumin (Cur) in fat-free food is limited due to its poor water solubility, stability, and bioaccessibility. In this study, zein-gum arabic-tannic acid (zein-GA-TA) composite particles with high physical stability were fabricated to deliver Cur (ZGT-Cur). Their stability and in vitro release properties were also evaluated. The results showed that the thermal and photochemical stability of Cur was improved after loading into composite particles. Meanwhile, the retention rate of Cur in ZGT-Cur composite particles was enhanced compared with Z-Cur or ZG-Cur particles. Fourier transform infrared (FTIR) spectroscopy confirmed that the hydrogen bond within the particles was greatly enhanced after the addition of tannic acid (TA). The in vitro antioxidant activity of Cur in ZGT-Cur composite particles was higher in terms of 2,2'-azino-bis (ABTS) (93.64%) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) (50.41%) compared with Z-Cur or ZG-Cur particles. The bioaccessibility of Cur in ZGT-Cur composite particles was 8.97 times higher than that of free Cur. Therefore, the particles designed in this study will broaden the application of Cur in the food industry by improving its stability and bioaccessibility.

Effects of M/G Ratios of Sodium Alginate on Physicochemical Stability and Calcium Release Behavior of Pickering Emulsion Stabilized by Calcium Carbonate

The gel properties of sodium alginate (SA) have been revealed to be strongly correlated with its ratio of D-mannuronate to L-guluronate (M/G ratio). Herein, we focused on SA with different M/G ratios to conduct an in-depth study on the effect of the M/G ratio difference on physicochemical stability and calcium release behavior of the Pickering emulsion stabilized by calcium carbonate (CaCO₃). The oil phase was added to the aqueous phase, prepared by SA with different M/G ratios (2.23, 0.89, and 0.56) and CaCO₃, for one-step shearing to obtain the E1, E2, and E3 emulsions, respectively. The results of the particle size, microstructure, long-term stability, rheological, and microrheological properties of the emulsions showed that the E3 emulsion, prepared by SA with a smaller M/G ratio, had a smaller particle size and has remained in a flow condition during the long-term storage, while the E1 and E2 emulsions had a gelation behavior and a stronger viscoelasticity. Moreover, the emulsion, as a liquid calcium supplement, is not only convenient for oral intake while meeting the calcium needs of the body, but also controls the release of Ca²⁺. The calcium release of the emulsions in a simulated gastric environment demonstrated that the calcium release ratio increased with the decrease of SA concentration, with the increase of M/G ratio, and with the decrease of oil phase volume.

Enhanced stability and controlled gastrointestinal digestion of β-carotene loaded Pickering emulsions with particle-particle complex interfaces

In this study, we used large, rigid, and hydrophilic zein-propylene glycol alginate composite particles (ZPCPs) and small, soft, and hydrophobic whey protein microgel (WPM) particles to synergistically stabilize a Pickering emulsion for delivery of β-carotene. The photothermal stability and storage stability of β-carotene were improved with the combined use of different particles. Microstructural observations showed that ZPCPs were effectively adsorbed at the oil/water interface despite the substantial interparticle gaps. WPM particles could swell and stretch on the interface due to their deformable structure, thereby forming an interfacial layer of flattened particles to cover a large surface area. The interfacial structure and macroscopic properties of Pickering emulsions were modulated by adjusting the mass ratio and addition sequence of different particles. The combination of ZPCPs and WPM delayed the lipolysis during gastrointestinal digestion. Through controlling the composition of the complex interface, the free fatty acid (FFA) release rate of Pickering emulsions in the small intestinal phase was reduced from 15.64% to 9.03%. When ZPCPs were used as the inner layer and WPM as the outer layer and the mass ratio of ZPCPs to WPM was 4 : 1, the Pickering emulsion showed the best stability and β-carotene bioaccessibility. The Pickering emulsion with particle-particle complex interfaces could be applied in foods and pharmaceuticals for the purpose of enhanced stability, delayed lipolysis or sustained nutrient release.

Zein Colloidal Particles and Cellulose Nanocrystals Synergistic Stabilization of Pickering Emulsions for Delivery of β-Carotene

In this study, we utilized different types of particles to stabilize β-carotene-loaded Pickering emulsions: spherical hydrophobic zein colloidal particles (ZCPs) (517.3 nm) and rod-shaped hydrophilic cellulose nanocrystals (CNCs) (115.2 nm). Either of the particles was incapable of stabilizing Pickering emulsions owing to their inappropriate wettability. When the mass ratio of ZCPs and CNCs was 1:4, the Pickering emulsion showed the best physical and photothermal stability. Compared to the ZCP-stabilized Pickering emulsion (9.29%), the retention rate of β-carotene in the Pickering emulsion costabilized by ZCPs and CNCs was increased to 60.23% after 28 days of storage at 55 °C. Confocal microscopy and cryoscanning electron microscopy confirmed that different types of particles could form a multilayered structure or induce the formation of an interparticle network. Furthermore, the complexation of ZCPs and CNCs delayed the lipolysis of the emulsion during in vitro digestion. The free fatty acid (FFA) release rate of Pickering emulsions in the small intestinal phase was reduced from 19.46 to 8.73%. Accordingly, the bioaccessibility of β-carotene in Pickering emulsions ranged from 9.14 to 27.25% through adjusting the mass ratio and addition sequence of distinct particles at the interface. The Pickering emulsion with the novel particle-particle complex interface was designed in foods and pharmaceuticals for purpose of enhanced stability, delayed lipolysis, or sustained nutrient release.

Metal-Organic Framework-Stabilized High Internal Phase Pickering Emulsions Based on Computer Simulation for Curcumin Encapsulation: Comprehensive Characterization and Stability Mechanism

High internal phase Pickering emulsions (HIPPEs) have taken a center stage in the arena of delivery systems in the food industry because of their high loading capacity and stability. In addition, metal-organic frameworks (MOFs), a type of cutting-edge designable porous scaffolding material, have attracted attention in reticular chemistry, which satisfies fundamental demands for delivery research in the past years. Here, we demonstrate a novel metal-organic framework (MOF)-stabilized HIPPE delivery system for hydrophobic phytochemicals. First, a novel high-biocompatibility and stable MOF particle, UiO-66-NH₂, was selected from atomic simulation screening, which showed proper electronegativity and amphiphilic properties to develop the HIPPE system. Monodispersed UiO-66-NH₂ nanoparticles with the particle size of 161.36 nm were then prepared via solvothermal synthesization. Pickering emulsions with inner phase ratios from 50 to 80% with varied contents of polyethylene glycol (PEG) were prepared by in situ high-pressure homogenization, and their physicochemical properties including crystallography, morphology, and rheology were systematically characterized. Subsequently, curcumin, a model antioxidant, was loaded in the HIPPE system and named cur@UiO-66-NH₂/HIPPE. It exhibited high loading capacity, up to 6.93 ± 0.41%, and encapsulation efficiency (19.76 ± 3.84%). This novel MOF nanoparticle-stabilized HIPPE delivery system could be practically utilized for other bioactive components and antimicrobial agents, which would find applications in food safety and biomedical areas in the future.

Pickering Emulsions Simultaneously Stabilized by Starch Nanocrystals and Zein Nanoparticles: Fabrication, Characterization, and Application

Using two types of colloidal particles having natural origins to synergistically stabilize Pickering emulsions is essential for food, cosmetics, and pharmaceutics, especially when neither particle can stabilize the Pickering emulsions alone. The use of two natural stabilizers avoids the complicated surface treatments of particles and the introduction of poisonous or harmful chemicals. In this work, we report an all-natural Pickering emulsion stabilized synergistically by starch nanocrystals and zein protein nanoparticles. Our result shows that the electrostatic interaction between the two types of particles greatly affects their assembled structure at the oil/water interface, which is closely related to the emulsion stability. Specifically, particle bilayers could form with oppositely charged particles at the interface to endow the emulsion with improved stability. As a demonstration, the resultant Pickering emulsions effectively carry β-carotene and have high stability against high temperatures and ultraviolet radiation. This type of all-natural Pickering emulsion is a promising tool to protect and deliver liposoluble bioactive components.

The construction of resveratrol-loaded protein-polysaccharide-tea saponin complex nanoparticles for controlling physicochemical stability and in vitro digestion

The novel zein-propylene glycol alginate (PGA) -tea saponin (TS) ternary complex nanoparticles were fabricated to deliver resveratrol. TS was firstly introduced to modulate the functional attributes, microstructure, molecular interactions and gastrointestinal digestion of the complex nanoparticles. The size of zein-PGA-TS complex nanoparticles was between 281.9 and 309.7 nm. In the presence of TS, the encapsulation efficiency of resveratrol was significantly elevated from 58.43% to 85.58%. The environmental stability of resveratrol was improved through entrapping into the complex nanoparticles with the rise in TS proportion. Multiple spectroscopic methods revealed that TS altered the micro-environment and secondary structure of the protein. Hydrogen bonds, hydrophobic effects and electrostatic interactions contributed to the formation of complex nanoparticles. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) patterns showed the amorphous nature of the encapsulated resveratrol. Field emission scanning electron microscopy (FE-SEM) confirmed the globular shape of the nanoparticles and their different aggregation states were dependent on the particle compositions. Moreover, the zein-PGA-TS complex nanoparticles exhibited the best sustained release in the small intestine when the mass ratio of zein to TS was 5 : 1 (23.20% in the stomach and 63.11% in the small intestine). These findings indicated the influence of TS on the properties and applications of the protein-polysaccharide complexes, which provided a new insight into the development of novel food grade nanoparticles with desirable stability and digestion behaviour.

The microstructure and physiochemical stability of Pickering emulsions stabilized by chitosan particles coating with sodium alginate: Influence of the ratio between chitosan and sodium alginate

The purpose of this study was to further improve the physiochemical stability of the chitosan (CS) particle-stabilized Pickering emulsion by coating with sodium alginate (SA). The effect of different mass ratios of CS and SA (1:0.5-1:2) on the microstructure, rheology and the stability of the emulsions were comprehensively evaluated by various methods such as optical microscope, scanning electron microscope, rheometer, and low-field nuclear magnetism. The multilayer emulsion with low content of SA (CS:SA = 1:0.5) presented bridging flocculation. If SA concentration was high (CS:SA = 1:1-1:2), the surface of the Pickering emulsion droplets was completely covered by the SA. At this time, multilayer emulsion droplets became stable due to strong electrostatic and/or steric repulsion. Too high SA concentration (CS:GA = 1:2) might also promote the accumulation of moisture. In addition, the CS/SA multilayer emulsion showed higher coalescence stability under different environmental treatments but its creaming stability and flocculation stability were still sensitive to pH (2, 4 and 10), temperature (4 °C and 80 °C) and ionic strength (300-500 mM). In all, the addition of the proper level SA (CS:GA = 1:1-1:2) could increase the stability of CS particle-stabilized Pickering emulsion.

Development of β-carotene loaded oil-in-water emulsions using mixed biopolymer-particle-surfactant interfaces

In this study, β-carotene loaded oil-in-water emulsions were stabilized by complex interfaces composed of propylene glycol alginate (PGA), rhamnolipids (Rha), and zein colloidal particles (ZCPs). The influence of mixed biopolymer-surfactant, biopolymer-particle, surfactant-particle and biopolymer-surfactant-particle interfaces on the performance of the emulsions was investigated. The stability, microstructure, rheological properties, and in vitro gastrointestinal digestion of the emulsions were controlled by regulating the adding sequence and mass ratio of the multiple stabilizers. The droplet size of the emulsion was in the range of 14-77 μm. After encapsulation into the emulsions stabilized by the complex interfaces, the photothermal stability of β-carotene were increased by 41.53% and 21.52%, respectively. The co-existence of particles, biopolymers, and surfactants could induce competitive displacement, multilayer deposition and an interparticle network at the interface. Compared with a single PGA- or Rha-stabilized emulsion, the complex interface-stabilized emulsion reduced the release of FFA by 28.06% and 26.16%, respectively. The interfacial composition of the emulsion and the delayed lipid digestion further affected the bioaccessibility of β-carotene in the gastrointestinal tract (GIT). The mixed biopolymer-particle-surfactant interface-stabilized emulsion could be incorporated in foods, pharmaceuticals and cosmetics for excellent stability, targeted nutrient delivery and controlled lipolysis.

Prolamin-based complexes: Structure design and food-related applications

Prolamins are a group of safe food additives that are biocompatible, biodegradable, and sustainable. Zein, gliadin, kafirin, and hordein are common prolamins that have been extensively studied, particularly as these form colloidal particles because of their amphiphilic properties. Prolamin-based binary/ternary complexes, which have stable physicochemical properties and superior functionality, are formed by combining prolamins with polysaccharides, polyphenols, water-soluble proteins, and surfactants. Although the combination of prolamins with other components has received attention, the relationship between the structural design of prolamin-based complexes and their functionalities remains uncertain. This review discusses the production methods of prolamin-based complexes, the factors influencing their structural characteristics, and their applications in the food industry. Further studies are needed to elucidate the structure-function relationships between prolamins and other biopolymers, as well as the toxicological effects of these complexes in food.

Stability, Interfacial Structure, and Gastrointestinal Digestion of β-Carotene-Loaded Pickering Emulsions Co-stabilized by Particles, a Biopolymer, and a Surfactant

Novel Pickering emulsions were stabilized by complex interfaces in the presence of zein colloidal particles (ZCPs), propylene glycol alginate (PGA), and rhamnolipid (Rha) for delivery of β-carotene. The influence of the particle-surfactant, particle-biopolymer, and particle-biopolymer-surfactant mixed interfaces on the physiochemical properties and digestion fate of Pickering emulsions was investigated. It is the first time that three different types of emulsifiers have been used to synergistically stabilize food Pickering emulsions for delivery of lipophilic nutraceuticals. The physicochemical stability, microstructure, rheological properties, and in vitro gastrointestinal digestion of Pickering emulsions were controlled by the addition sequence and mass ratio of multiple stabilizers, which showed the enhanced stability and delayed lipid digestion of the particle-biopolymer-surfactant-stabilized Pickering emulsions. After encapsulation into Pickering emulsions, the retention rate of β-carotene increased 2-fold under UV radiation for 8 h. The coexistence of ZCPs, PGA, and Rha could induce the competitive displacement, multilayer deposition, and interparticle network at the interface. The combination of particles, a biopolymer, and a surfactant delayed the lipolysis during in vitro gastrointestinal tract. By modulating the interfacial composition, the release rate of free fatty acids from Pickering emulsions was reduced from 19.46% to 2.83% through different mechanisms. The novel Pickering emulsion could be incorporated in foods as well as pharmaceuticals for controlled lipid digestion or targeted nutrient delivery purposes.

Interactions of β-carotene with WPI/Tween 80 mixture and oil phase: Effect on the behavior of O/W emulsions during in vitro digestion

This study investigated the impact of adding β-carotene on the structure of fresh O/W emulsions with different oil phase (sunflower oil-LCT or NEOBEE®1053-MCT) and emulsifiers (WPI, Tween 80 - T80 or WPI/T80 mixture). In this sense, the behavior of emulsions through the gastrointestinal tract, the stability and bioaccessibility of β-carotene were also assessed. The β-carotene reduced the interfacial tension of the LCT/MCT-water systems. The addition of β-carotene promoted an increase of viscoelasticity of LCT/MCT-T80 (0.5%WPI/0.5%T80 and 1%T80 w/w) interfaces, but an increase of WPI content reduced the viscoelasticity of interfacial layers (LCT/MCT-1% WPI). These changes in the interface properties influenced the mean droplet size and ζ-potential of the fresh emulsions. LCT systems presented similar bioaccessibility/stability of β-carotene. However, β-carotene entrapped within protein-coated MCT droplets was more stable than within T80-MCT systems. Our results show that β-carotene interacted with other ingredients of emulsions changing their properties and behavior under gastrointestinal tract as well as the stability/bioaccessibility of β-carotene.

High stability of bilayer nano-emulsions fabricated by Tween 20 and specific interfacial peptides

To ensure emulsions to be continuously stable, the hydrolysates recovered from cod bones by papain acted as a natural surfactant to synthesize high-stability bilayer nano-emulsions. As assisted by Tween 20, the average diameter of synthesized nano-emulsion with enzymatic hydrolysate could exhibit stability between 300-400 nm under a broad range of pH (4-8), temperatures (30-90 °C) and salt concentration (25-250 mM). With the addition of the hydrolysates, the rate of increase of the TBARS value in the emulsion decreased. Moreover, the bilayer structure of the nano-emulsion was characterized under an atomic force microscopy and a cryo-scanning electron microscopy. Nano-LC-Q-TOF-MS was adopted to primarily identify peptides that contained hydrophobic and hydrophilic amino acids at the emulsion interface. Besides, the absorbed peptides on the interface of emulsion enhanced the stability of emulsion lipid oxidation.

Fabrication, Physicochemical Stability, and Microstructure of Coenzyme Q10 Pickering Emulsions Stabilized by Resveratrol-Loaded Composite Nanoparticles

The aim of this study was to develop a novel system for the co-delivery of resveratrol and coenzyme Q10 (CoQ10). It was achieved with a combination of resveratrol-loaded composite nanoparticles and CoQ10-loaded Pickering emulsions. Different levels of resveratrol (0.05-0.30%, w/v) were entrapped into composite nanoparticles by the method of emulsification-evaporation. The size of composite nanoparticles was around 300-600 nm, and the maximum loading capacity of resveratrol was up to 13.88% (w/w). Hydrogen bonds, hydrophobic effects, and electrostatic attraction participated in the self-assembly of composite nanoparticles. The stability of CoQ10 Pickering emulsions was monitored under simulated environmental stresses (pH, ionic strength, UV radiation, and heat) and accelerated storage conditions. The physical stability of Pickering emulsions was dependent on the particle compositions, and the CoQ10 entrapped was also protected by the resveratrol-loaded nanoparticles. The morphology of Pickering emulsions was observed with the aid of optical microscopy, confocal laser scanning microscopy, and cryo-scanning electronic microscopy. The nutraceutical Pickering emulsions were designed for the co-delivery of resveratrol and CoQ10, which has the potential to be a novel vehicle for bioactive ingredients.