Effect of the Solid Fat Content on Properties of Emulsion Gels and Stability of β-Carotene

Emulsion gels stabilized by cyclodextrin inclusion/chitosan complexes with varying OSA substitution degree for co-encapsulation of bioactive compounds

Co-encapsulation of bioactive compounds using interfacial β-cyclodextrin (β-CD) cavities and the internal oil phase of emulsion gels presents a promising approach. This study prepared octenyl succinic anhydride (OSA)-modified cyclodextrin-resveratrol (OCD-R) inclusion complexes with varying substitution degrees (DS) and combined them with chitosan (CS) to form OCD-R/CS complexes via electrostatic interactions. Results confirmed the successful encapsulation of resveratrol (RES) within the hydrophobic cavity of cyclodextrin. Increasing DS led to reduced ζ potential and fluctuating interfacial tension. All composite emulsion gels exhibited non-flowing properties and comparable oil droplet sizes. Notably, OCD1-R/CS emulsion gels were suitable for stabilizing β-carotene (CAT)-containing oil droplets with solid-like structure and demonstrated excellent 3D printability. The interfacial encapsulation of RES improved the retention ratio of CAT in the oil phase, contributing to increased bioaccessibility for RES (57.89 %) and CAT (44.29 %). These results may provide an alternative for developing co-encapsulating carriers for bioactive compounds with different solubilities.

Walnut glutenin peptide-based-rhamnolipid composite emulsion gels: Preparation, characterization and application as margarine alternatives

In this study, peptide (WG-E40) derived from hydrolyzed walnut glutenin (WG) and rhamnolipid (Rha) were combined to develop peptide-based emulsion gel (PEG) with β-sitosterol as gelling agent. Among the hydrolysis products of WG at different hydrolysis times (2, 20, and 40 min), WG-E40 exhibited the best gelling performance. The effects of WG-E40 and Rha on PEG properties were evaluated through particle size analysis, fourier transform infrared spectroscopy, rheology, microstructure, and oil retention capacity (OHC). PEG formulated with WG-E40 and Rha showed porous structure, solid gel viscoelasticity and OHC of 71.27 %. Rha has improved the emulsifying ability of WG-E40 and enhanced its stability. In vitro digestion experiments showed that these PEGs encapsulated curcumin at a rate of 91.75 %, slowing down its release in simulated gastrointestinal fluid. Additionally, GC-MS analysis revealed that sponge cakes prepared with PEG exhibited favorable flavor profiles, suggesting their potential as a healthier alternative to margarine.

Improving stability and β-carotene bioaccessibility of shellac nanoparticles-based Pickering emulsion gels via amorphous cationic starch complexation

This paper attempted to construct shellac nanoparticles (SNP)-Pickering emulsion gels to enhance both stability and β-carotene bioaccessibility, incorporating amorphous cassava starch modified with (3-chloro-2-hydroxypropyl) trimethyl ammonium chloride (CS) as a co-stabilizer. Results showed that the surface properties of SNP/CS were engineered to gain the most suitable wettability (θ = 93°). Molecular docking and zeta-potential results revealed that hydrogen bonds and electrostatic interactions played a dominant role in the formation of SNP/CS mixtures. The appearance, micromorphology, oil droplet size, and rheological results suggested that the optimal stability of emulsion gels was achieved with an oil fraction of 70 %, an emulsifier concentration of 1 %, and an SNP/CS ratio of 4/1. Amorphous starch served not only as a co-stabilizer but also as a gelling agent, with its long chains in the matrix facilitating the formation of a dense and cohesive network that enhanced the stability of emulsion gel. The SNP/CS (4/1) stabilized emulsion gel exhibited increased viscosity and mechanical strength compared to the SNP-only stabilized sample. Notably, SNP/CS (4/1) emulsion displayed the highest β-carotene bioaccessibility (26.1 %). These findings underscore the potential of SNP/CS mixtures as effective stabilizers for emulsion gels, opening up new possibilities for their application in nutrient delivery.

Impact of solid-to-liquid lipid ratio on the gelation and emulsion properties of lamb myofibrillar protein gels

The effects of different olive and coconut oil ratios on the physicochemical and rheological properties of lamb myofibrillar protein emulsion gels were investigated. Solid fat index and viscosity analyses revealed that optimal solid-to-liquid fat ratios enhanced gel strength and emulsion stability by forming dense protein-fat interfacial layers. Medium-chain triglycerides of coconut oil contribute to increased viscosity at lower temperatures, whereas excessive amounts (>60 % of total lipid) disrupt the protein matrix and weaken the gel strength. Fourier-transform infrared spectroscopy analysis showed that moderate coconut oil levels promoted α-helix formation, improving protein stability and water-holding capacity, whereas excessive incorporation led to random coil formation and lower water retention. Rheological analysis confirmed the highest storage modulus at 40 %-60 % coconut oil, supporting the strongest gel network. The morphological analysis revealed smaller and more uniformly distributed pores at optimal ratios, corresponding to superior mechanical strength and stability. These findings demonstrate the critical role of the oil composition in determining the structural and functional properties of emulsion gels.

Development of interpenetrating network gels based on co-gelation of heteroprotein aggregates and sugar beet pectin for physicochemical functional enhancement of W-O-W systems

The advancement and utilization of functional foods hold the capacity to efficaciously enhance human nutrition and well-being. However, within the present epoch characterized by recurrent food safety and quality concerns, there exists a paucity of suitable food systems that are capable of concurrently amalgamating the merits of nutritional enrichment and high stability. Therefore, in this study, heteroprotein aggregates were synthesized with modified-soy lipophilic protein (SLP) and lysozyme (LY) as the main components. Subsequently, an interpenetrating network (IPN) was constructed using sugar beet pectin (SBP) and heteroprotein aggregates to form W-O-W emulsion gels. The heteroprotein aggregates formed by SLP and LY provided a stable oil-water interface, allowing the IPN to maximally confine the internal oil droplets and improve the mechanical properties and water retention capacity of the W-O-W emulsion gels. Meanwhile, the W-O-W emulsion gels also possessed pH-responsiveness, endowing them with the ability to modulate their self-morphology and network structure in accordance with pH fluctuations. Moreover, they possessed outstanding protective and slow-release efficacies, which were conducive to the targeted release of the delivered substances. Thus, W-O-W emulsion gels based on heteroprotein aggregation and SBP show great potential as an option for functional food applications.

Development of emulsion gels as animal fat analogs: The impact of soybean and coconut oil concentration on rheological and microstructural properties

This study investigates the effect of oil type and concentration on the rheological and microstructural properties of plant-based emulsion gels, comparing them to animal fat tissue. Emulsion gels were formulated with soybean or coconut oil, isolated soy protein, agar, and alginic acid at varying oil concentrations (0-30 %). The structural integrity of animal fat is attributed to a fibrous network of adipocytes and collagen. In contrast, oil concentration significantly affected the gel network density, with coconut oil-based gels maintaining stable viscoelasticity, while soybean oil-based gels exhibited more fluid-like behavior. The thermal behavior of the gels was significantly influenced by the fatty acid composition of the oils, with a distinct endothermic peak observed around 20 °C for coconut oil-based gels, while no peak appeared for soybean oil-based gels. These findings highlight the potential to optimize plant-based fat analogs by controlling oil type and concentration to replicate animal fats in plant-based food products.

The assembly mechanism of Zein/EGCG/PEG nanoparticles in a water system and their adsorption behavior at the oil-water interface

In this study, the self-assembly mechanism of Zein/(-)-epigallocatechin-3-gallate/polyethylene glycol (Zein/EGCG/PEG) composite nanoparticles and their interface adsorption behavior at the oil-water interface were investigated by coarse-grained molecular dynamics simulation. Fourier transform infrared spectroscopy and conformation analysis demonstrated that there were electrostatic and hydrogen bond interactions between Zein and EGCG, physical entanglement between PEG and Zein, and hydrogen bond interaction between EGCG and PEG. The nanoparticles accumulated at the oil-water interface, and there was an obvious interface layer between oil phase and water phase, as indicated by confocal laser scanning microscope and scanning electron microscope. The adsorbing of Zein/EGCG/PEG nanoparticles at the oil-water interface was confirmed by coarse-grained molecular dynamics simulation. Further findings confirmed that Zein/EGCG/PEG nanoparticles could serve as stabilizers for oleogels with self-supporting structure, viscoelastic solid behavior and temperature response characteristics. The current research offered a novel approach to enhance protein interface characteristics and create food-grade emulsifiers and oleogelators.

Recent research and applications in lipid-based food and lipid-incorporated bioink for 3D printing

Three-dimensional (3D) printing, as an emerging digital production technology, has recently been receiving increasing attention in food processing. It is important to understand the effect of key ingredients of food materials on the printing, which makes it possible to achieve a wider range of structures using few nozzles and to provide tailored nutrition and personalization. This comprehensive review delves into the latest research on 3D-printed lipid-based foods, encompassing a variety of products such as chocolate, processed cheese, as well as meat. It also explores the development and application of food bioinks that incorporate lipids as a pivotal component, including those based on starch, protein, oleogels, bigels, and emulsions, as well as emulsion gels. Moreover, this review identifies the current challenges and presents an outlook on future research directions in the field of 3D food printing, especially the research and application of lipids in food 3D printing.

Sodium caseinate/gellan gum emulsion gels for zeaxanthin dipalmitate delivery: Preparation, characterization, and gelation mechanism

The emulsion gel composed of proteins and polysaccharides exhibits significant potential as a targeted delivery system for bioactives in the gastrointestinal tract. In this study, a composite emulsion was prepared by using sodium caseinate (NaCas) and gellan gum (GG), which was subsequently crosslinked with transglutaminase (TG), glucono-δ-lactone (GDL), and calcium ions (Ca2+) to form emulsion gels. The physicochemical properties of the NaCas/GG emulsion gels were characterized to verify the effects of zeaxanthin dipalmitate encapsulation and protection, and a possible mechanism was discussed. The appearance and microscopy analyses revealed that the Ca2+-induced NaCas/GG emulsion gel exhibited superior shape retention and a denser network structure compared to GDL or TG crosslinking methods. The rheological analysis demonstrated that the Ca2+-crosslinked emulsion gels had higher modulus and hardness than their TG- or GDL- crosslinked counterparts. Infrared spectroscopy, molecular docking, and gelling force analysis revealed that the gelation mechanism of these emulsion gels primarily involved carbonyl-amide group crosslinking reactions, hydrogen bonding, and hydrophobic interactions. Furthermore, the Ca2+-crosslinked emulsion gel encapsulating zeaxanthin dipalmitate exhibited excellent thermal stability, resistance to gastrointestinal conditions, and stability. Overall, the above findings highlight that using Ca2+ crosslinking in NaCas/GG composite emulsion yields edible composite materials with enhanced functional performance, thereby expanding the possibilities for food gel design strategies.

Emulsion gels prepared from Longzhua mushroom polysaccharides with self-gelling properties as β-carotene carriers: Stability and in vitro digestibility of β-carotene

β-Carotene is widely used in food systems because of its biological activity; however, β-carotene has poor chemical stability and low bioavailability. Thus, researchers use encapsulated delivery systems to overcome these disadvantages. In this study, we prepared emulsion gels to encapsulate β-carotene, using Longzhua mushroom polysaccharide (LMP), which can autonomously form weak gels. The LMP emulsion gel (LEG) exhibited a high water-holding capacity of up to 95.06 %. All samples showed adequate storage stability for 28 days. Increasing the polysaccharide content in the emulsion gel enhanced the encapsulation efficiency of β-carotene (96.76 %-98.27 %), the release of free fatty acids (68.21 %-81.44 %), and the photostability (80.65 %-91.27 %), thermal stability (73.84 %-97.08 %), and bioaccessibility (18.28 %-30.26 %) of β-carotene. In conclusion, LEG is a promising fat-soluble material that can be used for food-grade encapsulated delivery systems.

Development of Oleogel-in-Water High Internal Phase Emulsions with Improved Physicochemical Stability and Their Application in Mayonnaise

Egg-free mayonnaise is receiving greater attention due to its potential health benefits. This study used whey protein isolate (WPI) as an emulsifier to develop high internal phase emulsions (HIPEs) based on beeswax (BW) oleogels through a simple one-step method. The effects of WPI, NaCl and sucrose on the physicochemical properties of HIPEs were investigated. A novel simulated mayonnaise was then prepared and characterized. Microstructural observation revealed that WPI enveloped oil droplets at the interface, forming a typical O/W emulsion. Increase in WPI content led to significantly enhanced stability of HIPEs, and HIPEs with 5% WPI had the smallest particle size (11.9 ± 0.18 μm). With the increase in NaCl concentration, particle size was increased and ζ-potential was decreased. Higher sucrose content led to reduced particle size and ζ-potential, and slightly improved stability. Rheological tests indicated solid-like properties and shear-thinning behaviors in all HIPEs. The addition of WPI and sucrose improved the structures and viscosity of HIPEs. Simulated mayonnaises (WE-0.3%, WE-1% and YE) were then prepared based on the above HIPEs. Compared to commercial mayonnaises, the mayonnaises based on HIPEs exhibited higher viscoelastic modulus and similar tribological characteristics, indicating the potential application feasibility of oleogel-based HIPEs in mayonnaise. These findings provided insights into the development of novel and healthier mayonnaise alternatives.

Stabilization of oil-in-water high internal phase emulsions with octenyl succinic acid starch and beeswax oleogel

High internal phase emulsions (HIPEs) based on beeswax (BW) oleogels and octenyl succinic acid starch (OSA starch) were prepared by a facile one-step method. Effects of the oleogelation of internal phase on the formation, stability and functionality of the HIPEs were investigated. OSA starch absorbed at the interface allowed high surface charge (|ζ| > 25 mV) of the droplets, and small droplet size (d ≈ 5 m). Microstructural observation suggested that the HIPEs were of O/W type with droplets packed tightly. With the increase in BW content (0-4 %), the particle size (4-7 μm) and ζ-potential (-25 ~ -30 mV) of the HIPEs were first decreased and then increased. Stability analysis revealed that the addition of BW effectively improved emulsion stability against centrifugation, freeze-thawing, changes in pH and ionic strength, and the HIPE with 2 % BW presented the best stability. Rheological tests indicated that the HIPEs with higher content of BW exhibited higher storage modulus, solid-like properties, and shear thinning behaviors. Creep-recovery results implied that the oleogelation enhanced the structure of HIPEs and improved the deformation resistance of the systems. When subjected to light and heat, oleogel-in-water HIPEs showed advantages in protecting β-carotene from degradation, and β-carotene in the HIPEs with 2 % BW had the lowest degradation rate. These findings suggested that gelation of oil phase could improve the stability of HIPEs and the encapsulation capability, which would be meaningful for the development of novel healthy food.

Rheological property, β-carotene stability and 3D printing characteristic of whey protein isolate emulsion gels by adding different polysaccharides

Emulsion gels with unique structural and mechanical properties have promising applications in 3D food printing. The purpose of this paper was to investigate the rheological property, β-carotene stability and 3D printing characteristic of whey protein isolate (WPI) emulsion gels by adding guar gum (GG), locust bean gum (LBG), xanthan gum (XG) and gum arabic (GA). The results showed that all samples exhibited shear thinning behavior and elastic characteristic. XG could reduce water mobility and increase WHC of WPI emulsion gel. The disulfide bond was the main chemical molecular force of emulsion gels, and XG significantly increased the hydrophobic interactions. GG and LBG increased gel strength, hardness and gumminess, reduced springiness, cohesiveness and chewiness of emulsion gels. GG sample had the best printing performance, more uniform network structure and better stability of β-carotene. This study provided a theoretical basis for 3D printing functional food.

Protein-Stabilized Emulsion Gels with Improved Emulsifying and Gelling Properties for the Delivery of Bioactive Ingredients: A Review

In today's food industry, the potential of bioactive compounds in preventing many chronic diseases has garnered significant attention. Many delivery systems have been developed to encapsulate these unstable bioactive compounds. Emulsion gels, as colloidal soft-solid materials, with their unique three-dimensional network structure and strong mechanical properties, are believed to provide excellent protection for bioactive substances. In the context of constructing carriers for bioactive materials, proteins are frequently employed as emulsifiers or gelling agents in emulsions or protein gels. However, in emulsion gels, when protein is used as an emulsifier to stabilize the oil/water interface, the gelling properties of proteins can also have a great influence on the functionality of the emulsion gels. Therefore, this paper aims to focus on the role of proteins' emulsifying and gelling properties in emulsion gels, providing a comprehensive review of the formation and modification of protein-based emulsion gels to build high-quality emulsion gel systems, thereby improving the stability and bioavailability of embedded bioactive substances.

Tailoring a novel ovalbumin emulsion gel for stability improvement and functional properties enhancement: Effect of oil phase structure changes by beeswax

This study aimed to form a novel emulsion gel (EG) through structured oil phase of natural component beeswax (BW), together with ovalbumin (OVA), and to investigate the mechanism of its formation and stabilization in terms of microstructure and processing properties. Confocal laser scanning microscopy (CLSM) demonstrated that the EG formed a continuous double network structure since the superior crystallinity of the oil phase was given by BW. Fourier transform infrared spectroscopy (FT-IR) illustrated that the acylation of the phenolic hydroxyl group in BW with an amide bond in OVA, increased the hydrogen bonding of EG. Furthermore, the immobilization of the oil phase results in better thermal and freeze-thaw stability of EG. Finally, EG was used as a curcumin delivery system, and the presence of BW significantly improved its adaptability to multiple environmental factors. In summary, our study would provide valuable ideas for developing the design of finely structured functional food.

Formulation and Characterization of Emulgel-Based Jelly Candy: A Preliminary Study on Nutraceutical Delivery

The development of consumer-friendly nutraceutical dosage forms is highly important for greater acceptance. In this work, such dosage forms were prepared based on structured emulsions (emulgels), where the olive oil phase was filled within the pectin-based jelly candy. The emulgel-based candies were designed as bi-modal carriers, where oil-soluble curcumin and water-soluble riboflavin were incorporated as the model nutraceuticals. Initially, emulsions were prepared by homogenizing varied concentrations (10% to 30% (w/w)) of olive oil in a 5% (w/w) pectin solution that contained sucrose and citric acid. Herein, pectin acted as a structuring agent-cum-stabilizer. Physico-chemical properties of the developed formulations were thoroughly analyzed. These studies revealed that olive oil interferes with the formation of polymer networks of pectin and the crystallization properties of sugar in candies. This was confirmed by performing FTIR spectroscopy and DSC studies. In vitro disintegration studies showed an insignificant difference in the disintegration behavior of candies, although olive oil concentration was varied. Riboflavin and curcumin were then incorporated into the jelly candy formulations to analyze whether the developed formulations could deliver both hydrophilic and hydrophobic nutraceutical agents. We found that the developed jelly candy formulations were capable of delivering both types of nutraceutical agents. The outcome of the present study may open new directions for designing and developing oral nutraceutical dosage forms.

Effects of Concentration and Type of Lipids on the Droplet Size, Encapsulation, Colour and Viscosity in the Oil-in-Water Emulsions Stabilised by Rapeseed Protein

The objective of this study was to extract the rapeseed protein from by-products and further examine the effect of lab-made rapeseed protein on the droplet size, microstructure, colour, encapsulation and apparent viscosity of emulsions. Rapeseed protein-stabilised emulsions with an increasing gradient of milk fat or rapeseed oil (10, 20, 30, 40 and 50%, v/v) were fabricated using a high shear rate homogenisation. All emulsions showed 100% oil encapsulation for 30 days of storage, irrespective of lipid type and the concentration used. Rapeseed oil emulsions were stable against coalescence, whereas the milk fat emulsion showed a partial micro-coalescence. The apparent viscosity of emulsions raised with increased lipid concentrations. Each of the emulsions showed a shear thinning behaviour, a typical behaviour of non-Newtonian fluids. The average droplet size was raised in milk fat and rapeseed oil emulsions when the concentration of lipids increased. A simple approach to manufacturing stable emulsions offers a feasible hint to convert protein-rich by-products into a valuable carrier of saturated or unsaturated lipids for the design of foods with a targeted lipid profile.

Food Emulsion Gels from Plant-Based Ingredients: Formulation, Processing, and Potential Applications

Recent advances in the understanding of formulations and processing techniques have allowed for greater freedom in plant-based emulsion gel design to better recreate conventional animal-based foods. The roles of plant-based proteins, polysaccharides, and lipids in the formulation of emulsion gels and relevant processing techniques such as high-pressure homogenization (HPH), ultrasound (UH), and microfluidization (MF), were discussed in correlation with the effects of varying HPH, UH, and MF processing parameters on emulsion gel properties. The characterization methods for plant-based emulsion gels to quantify their rheological, thermal, and textural properties, as well as gel microstructure, were presented with a focus on how they can be applied for food purposes. Finally, the potential applications of plant-based emulsion gels, such as dairy and meat alternatives, condiments, baked goods, and functional foods, were discussed with a focus on sensory properties and consumer acceptance. This study found that the implementation of plant-based emulsion gel in food is promising to date despite persisting challenges. This review will provide valuable insights for researchers and industry professionals looking to understand and utilize plant-based food emulsion gels.

Fabrication of anthocyanin–rich W1/O/W2 emulsion gels based on pectin–GDL complexes: 3D printing performance

The stability of anthocyanin-rich W₁/O/W₂ double emulsions prepared with Nicandra physalodes (Linn.) Gaertn. Seeds pectin was investigated, including droplet sizes, ζ-potential, viscosity, color, microstructures and encapsulation efficiency. Furthermore, the gelation behavior, rheological behavior, texture behavior and three-dimensional (3D) printing effects of the W₁/O/W₂ emulsion gels induced with Glucono-delta-lactone (GDL) were studied. The L*, b*, ΔE, droplet sizes and ζ-potential of the emulsions were gradually increased, while other indicators were gradually decreased during 28 days of storage under 4 ℃. The storage stability of sample under storage at 4 ℃ was higher than 25 ℃. The G' of W₁/O/W₂ emulsion gels gradually boosted with increased GDL addition, and reached the highest after the addition of 1.6 % GDL. In creep-recovery sweep, the minimum strain of 1.68 % and the highest recovery rate of 86 % were also found for the emulsion gels with 1.6 % GDL. Accordingly, the models "KUST", hearts, flowers printed by emulsion gels after 60 min addition of 1.6 % GDL had the best printing effects. The W₁/O/W₂ emulsion gels based on pectin-GDL complexes exhibited good performance in protecting anthocyanins and suggested as a potential ink for food 3D printing.

Recent progresses in the delivery of β-carotene: From nano/microencapsulation to bioaccessibility

Beta-carotene (BC) as an efficient pro-vitamin is effective in improving vision, immune system and cognitive function as well as preventing coronary diseases and cancer. However, besides its poor chemical stability, the high lipophilic nature of BC reduces its dispersibility and consequently bioavailability which limits its application into food, pharmaceutical and nutraceuticals. Different carriers with vesicular or particulate structures have been studied and utilized for promoting BC solubility, dispersibility, and protection against diverse operational or environmental stresses and also controlling BC release and subsequent bioaccessibility. The current study, therefore reviews different micro/nanocarriers reported on BC encapsulation with special focusing on its bioavailability. Liposomal structures have been successfully used for enhancing BC stability and bioavailability. Besides, emulsion-based carriers including Pickering emulsions, nanoemulsions and microemulsions have been widely evaluated for BC encapsulation and protection. In addition, lipid-based nanoparticles and nanostructural carriers have also been applied successfully for this context. Moreover, gel structures including emulgels, hydrogels and oleogels are studied in some researches. Most of these delivery systems led to higher hydro-solubility and dispersibility of BC which consequently increased its bioavailability; thereupon could promote its application into food, cosmetic and nutraceutical products. However, for remarkable incorporation of BC and other bioactive compounds into edible products, the safety and toxicological aspects of these delivery system especially those designed in nano scale should be addressed in the further researches.

Engineering Emulsion Gels as Functional Colloids Emphasizing Food Applications: A Review

Gels are functional materials with well-defined structures (three-dimensional networks) assembled from the dispersed colloids, and capable of containing a large amount of water, oil, or air (by replacing the liquid within the gel pores), known as a hydrogel, oleogel, and aerogel, respectively. An emulsion gel is a gelled matrix filled with emulsion dispersion in which at least one phase, either continuous phase or dispersed phase forms spatial networks leading to the formation of a semisolid texture. Recently, the interest in the application of gels as functional colloids has attracted great attention in the food industry due to their tunable morphology and microstructure, promising physicochemical, mechanical, and functional properties, and superior stability, as well as controlled release, features for the encapsulated bioactive compounds. This article covers recent research progress on functional colloids (emulsion gels), including their fabrication, classification (protein-, polysaccharide-, and mixed emulsion gels), and properties specifically those related to the gel-body interactions (texture perception, digestion, and absorption), and industrial applications. The emerging applications, including encapsulation and controlled release, texture design and modification, fat replacement, and probiotics delivery are summarized. A summary of future perspectives to promote emulsion gels' use as functional colloids and delivery systems for scouting potential new applications in the food industry is also proposed. Emulsion gels are promising colloids being used to tailor breakdown behavior and sensory perception of food, as well as for the processing, transportation, and targeted release of food additives, functional ingredients, and bioactive substances with flexibility in designing structural and functional parameters.

API-polymer interactions in Sepineo P600 based topical gel formulation- impact on rheology

In the present study, topical gel and emulsion gel were formulated using Acrylamide/ Sodium Acryloyldimethyl taurate copolymer (Sepineo P600) as a gelling agent, and their rheological attributes and physical stability were evaluated upon incorporation of API. Lidocaine, a free base drug (pK_a 7.92) was used as a model drug in all formulations. Medium- chain Triglycerides (MCT) was used as a dispersed phase to prepare the emulgel. Results show that the rheological properties of both gel and emulgel such as viscosity, elastic moduli and yield stress were significantly influenced by the pH of the topical formulations and API concentration. A lower pH (pH < pKa) leads to the increase in number of cationic species of lidocaine, which results in the weakening of the structure of the gel matrix by charge screening of polymer-polymer repulsions. Interactions between API and polymer chains through electrostatic attraction may play a major role in altering the rheology, which could potentially impact the physical stability against phase separation of the internal phase in emulsion gel samples. This study provides valuable insights into rheological behaviors of Sepineo P600 gel and emulgel which can be modified or tuned though the interplay of the API properties and critical formulation parameters such as pH. The tunable rheological properties with simpler manufacturing process make Sepineo P600 gel and emulsion gel very suitable systems for use in semisolid topical formulations.

Tailoring the properties of double-crosslinked emulsion gels using structural design principles: Physical characteristics, stability, and delivery of lycopene

Lycopene is claimed to have numerous physiological benefits, but its poor water solubility, chemical instability, and low bioavailability limit its application in functional foods and health care products. In this study, lycopene-loaded emulsions containing oil droplets with different interfacial structures were prepared and then cross-linked using transglutaminase (TG) and/or calcium ions (Ca²⁺) to form emulsion gels. The oil droplets were first coated by interfacial layers comprised of whey protein isolate (WPI) and sodium alginate (SA). During emulsion preparation, the SA was added either before or after homogenization to create complex or layer-by-layer coatings, respectively. Subsequently, TG and Ca²⁺ were used to cross-link WPI and SA to form emulsion gels. The results show that double-crosslinking increased the gel strength and viscosity of the emulsion gels. The layer-by-layer emulsion gels were stronger and more viscous than the complex ones. The photochemical and gastrointestinal stability of lycopene encapsulated within the emulsion gels was higher than that of free lycopene. An MTT toxicity test showed that the emulsion gels exhibited no cytotoxicity to Caco-2 cells. The lycopene-loaded emulsion gels exhibited stronger anti-inflammatory activity on the Caco-2 cells than the control. In addition, the absorption of lycopene by the Caco-2 cells increased after encapsulation. This study provides a new approach of preparing edible soft materials to enhance the application of hydrophobic bioactives (like lycopene) in functional foods.

Structural characterization of modified whey protein isolates using cold plasma treatment and its applications in emulsion oleogels

Cold plasma as a green and expeditious tool was used to modify whey protein isolate (WPI) in order to improve its emulsion capability. The emulsion-based oleogels with antibacterial functions were then constructed using the modified WPI. The modified WPI treated with cold plasma under 10 s at 50 W power significantly lowered the oil-water interface tension. Meanwhile, the fluorescence intensity and the α-helix content of WPI reduced with the cold plasma treatment. It is noted that SEM results showed that the treated WPI had more regular dendritic structures. Such modified WPI was applied to construct oleogels loaded with thyme essential oil and coconut oil, which showed a porous uniform network structure and excellent antimicrobial activities against E.coli. As a proof of concept, this study demonstrated cold plasma could be as a new facile tool to modify food-sourced proteins and expected to enlarge their applications in oleogel productions.

New insights into food O/W emulsion gels: Strategies of reinforcing mechanical properties and outlook of being applied to food 3D printing

3D printing technology has been widely used in food processing with its advantages of customized food design, personalized nutrition design, and simplified food supply chain. Food emulsion gels have application value and prospects in food 3D printing due to their promising properties, including biodegradability, biocompatibility, as well as dual characteristics of emulsions and biopolymer gels. Food emulsion gels with appropriate mechanical properties, as a new type of food inks, expand the types and functions of the inks. However, food emulsion gels without adequate reinforced mechanical properties may suffer from defects in shape, texture, mouthfeel, and functionality during 3D printing and subsequent applications. Therefore, it is necessary to summarize the strategies to improve the mechanical properties of food emulsion gels. According to the methods of characterizing the mechanical properties of emulsion gels, this article summarizes four strategies for improving the mechanical properties of emulsion gels through two ways: inside-out (reinforcement of interface and reinforcement of cross-linking) and outside-in (physical approaches and environmental regulations), as well as their basic mechanisms. The application status and future research trends of emulsion gels in food 3D printing are finally discussed.