Stability Of Gels Research Articles

In vitro skin permeation of flavonoid esters enzymatically derived from natural oils: release mechanism from gel emulsion, stability, and dermatological compatibility

Due to their broad spectrum of biological activities and attractive pharmacological properties, flavonoids are very promising molecules for application in skin care products. In this study, phloridzin and naringin medium- and long-chain fatty acid esters were enzymatically synthesized in reaction with natural oils (coconut and linseed oil) and in vitro transdermal delivery of synthesized esters through artificial Strat-M® membrane was investigated. Experimental results were succesfully fitted using Peppas and Sahlin model which includes the lag phase. Release kinetics of all examined flavonoid esters from gel emulsions through the membrane depended on both diffusion and polymer relaxation effect (0.5<n < 1). The estimated effective diffusion coefficients ranged from 0.168·10-8 to 6.149·10-8 cm2 s-1 for phloridzin esters and from 0.116·10-8 to 4.210·10-8 cm2 s-1 for naringin esters. The effective diffusion coefficients decreased with the increase in ester molecular weight indicating the size-dependent diffusion. All formulation showed good stability, excellent hydration effect, and excellent dermatological compatibility without irritating effect. It can be concluded that gel emulsions with a mixture of flavonoid esters enzymatically synthesized in reaction with vegetable oils can be effectively topically applied as a skin care products.

Fabrication and characterization of acidic high internal phase emulsion gels stabilized solely by wheat gluten for plant-based mayonnaise

Plant-based diets are currently gaining more popularity as a means of reducing the environmental footprint and promoting human health. Herein, plant protein-based acidic high internal phase emulsion gels (HIPE gels) were fabricated via a facile one-pot approach using wheat gluten (WG) solely. Pre-dissolving WG in edible vinegar-water solution was contributed to the fabrication of stable emulsion gels. Factors that affect the structure and performance of plant proteins as HIPE gels stabilizers were investigated. The results indicated that the stable HIPE gels could be formed with a vinegar concentration between 5 % and 20 % and a WG concentration of 1.0 %–7.5 % only. Microscopy images reveal that a collaboration of the soluble protein molecules adsorption and protein aggregate Pickering stabilization at oil-water interface, which was turned to form stable HIPE gels. In addition, the resulted HIPE gels exhibited shear thinning behavior, viscoelastic features, and good thixotropic recovery, which provide a similar perceived texture and sensory property for formulating egg-free mayonnaise. These findings provide a useful approach to construct HIPE-based softs from low-cost wheat gluten for preparing plant-based mayonnaise.

Two-ways regulation of the emulsion gel properties of curdlan by dry ball milling treatment and their relationships with the microstructures, emulsification characteristics and gel properties of ball milled curdlan

Ball milling treatment could affect the microstructures, improve the emulsification properties of curdlan (CL) and regulate the emulsion gel properties of CL based emulsion gel in two-ways. With increasing ball milling time (1 h–8 h), the particle size first decreased and then increased, the relative crystallinity decreased, and the contact angle increased. Ball milled curdlan (BMCL)-6 h showed the best emulsifying property and stability, which was the combined effects of decreased particle size and increased hydrophobic property. Ball milling 1 h and 2 h significantly improved the hardness and chewiness of CL-based emulsion gels, while, ball milling 4 h–8 h could make the emulsion gels much softer and ice cream-like. When the emulsion gels were heated twice consecutively, the visual appearance and texture properties did not change significantly, indicating the excellent thermal stability of these emulsion gels. The BMCL based emulsion gel with adjustable gel properties and good thermal stability has a wide range of uses in the food system.

Deacetylation enhances the structure and gelation properties of konjac glucomannan/soy protein isolate cold-set gels

This study aimed to investigate the effect of the deacetylated konjac glucomannan (DKGM), with varying degree of deacetylation (DD), on the physicochemical and structural properties of transglutaminase-induced soy protein isolate (SPI) cold-set gels. Compared with native konjac glucomannan (KGM), DKGM significantly enhanced the gel strength, water-holding capacity, and thermal stability of the composite gels, with DK3 (DKGM with 65.85 % deacetylation) showing the most significant improvement. The secondary and tertiary structures of SPI in the DK3 group were the most stable. Compared with the KGM group, the DK3 group showed a 58.32 % increase in hydrophobic interaction and a 37.98 % decrease in free sulfhydryl content. The microstructure results demonstrated that DK3 was uniformly dispersed within the SPI network, promoting the formation of a continuous and dense network structure. This was mainly due to DK3 having a moderate particle size and low viscosity. Therefore, DKGM with a moderate DD is conducive to forming a more ordered and dense gel network structure, imparting optimal gel performance to the SPI cold-set gel.

Resveratrol nanoparticles coated by metal-polyphenols supramolecular enhance antioxidant activity and long-term stability of dietary gel

Resveratrol (RES) is an important functional substance with multiple active properties. However, RES is susceptible to natural environmental conditions that reduce its bioactivity. To improve the bioavailability of RES, in this study, Catechin and Fe3+/Ca2+ were selected to form supramolecules, which were then coated on the surface of hydrophobic RES nanoparticles (RES NPs) to create composite RES NPs. The obtained composite RES NPs demonstrated higher antioxidant capacity and better photo-thermal stability than RES NPs. Additionally, a pectin (PE) dietary gel was designed as a delivery carrier for RES. The results showed that the incorporation of composite RES NPs not only endowed the gels with significant dietary activity but also enhanced the texture, water retention capacity and hydrophobicity. After 28 days of storage, the retention rate of RES could be maintained above 90 % in the dietary gels. Meanwhile, the controlled release of RES was achieved in in vitro simulated digestion.

Influence of starch on freeze-thaw stability of Hypophthalmichthys molitrix surimi gel observed via ice crystal distribution and gel properties

Starch has been recognized as a vital ingredient in surimi products due to its ability to absorb water, which reduces the deterioration of gels and water loss during freezing and thawing. However, it is essential to ascertain the role of starch in the formation of ice crystals and the texture of surimi gels. The impact of freeze-thaw cycles on the morphology and distribution of ice crystals, as well as the textural characteristics of gelatinized and ungelatinized starch-surimi gels was investigated. The results of light microscopy revealed that the presence of starch, irrespective of whether it was gelatinized, resulted in a reduction in the size of ice crystals within the surimi gel network during the freeze-thaw process. In addition, starch in surimi gels was subjected to freeze-thaw cycles, resulting in the emergence of two distinct states of bound water (0.1–1 ms and 1–10 ms). The higher relative content of immobile water indicated that the gelatinized starch had improved water holding properties. Furthermore, the incorporation of gelatinized starch into surimi enhanced its freeze-thaw stability and retarded the loss of gel strength, hardness, and whiteness. The addition of starch had a synergistic impact, enhancing the gel properties by affecting the formation of ice crystals and water absorption.

Investigating the impact of beeswax addition and diacylglycerol profiles on bigel properties and application in bread: insights on intermolecular interaction mechanisms

This study investigates the development of diacylglycerol (DAG)-based bigels as a healthier substitute for baking oil by combining hydroxypropyl methyl cellulose (HPMC)-based hydrogel with beeswax (BW)-based oleogel. Results indicated that increasing the concentration of BW enhances the interpenetration ability between the oleogel and hydrogel, leading to the formation of a stable bi-continuous bigel, as well as improved gel properties and thermal stability. The lipid profiles revealed that DAG's fatty acid composition could result in higher viscosity (0.075 ± 0.00 Pa.s) and lower interfacial equilibrium ability (14.02 ± 0.23 mN/m) compared to triglycerides (TAG). These characteristics contributed to enhanced mechanical properties and the maintenance of oil-water interface stability in the bigel. Spectroscopy and molecular dynamics simulations demonstrated that the DAG-based bigel could exhibit stronger van der Waals forces and hydrogen bonding between molecules compared to the TAG-based bigel. Consequently, DAG-based bigels showed superior gel properties and stability. Furthermore, textural analyses and sensory evaluations indicated that replacing 50% of butter with the DAG-based bigel in bread does not significantly alter the product compared to using 100% butter. This study underscores the potential of DAG in the preparation of bigels, promoting their application as the fat substitutes.

Effects of moderately oxidized lard on myofibrillar protein emulsion gels: Gel-forming properties, water distribution, and digestibility

Emulsion gels were prepared by adding lard with different degrees of oxidation (0, 1, 2, 3, 4, and 5 h, 110 °C) to porcine myofibrillar proteins (MP). The findings demonstrated that changes in sulfhydryl content and carbonyl content reflected that oxidized lard induced the oxidation of MP. Compared with the control (CON), moderately oxidized lard (2 h) led to the unfolding of the protein structure, increased β-sheet content, and exposed hydrophobic groups. These modifications facilitated interactions between the protein and lard at the interface, enhancing the emulsifying properties of MPs. Furthermore, the moderate oxidation of lard (2 h) enhanced the organization of the gel structure and improved the gel performance of MPs, resulting in uniform water distribution. In contrast, the hardness and springiness of MP gel treated with excessively oxidized lard (5 h) were significantly reduced (p < 0.05). The microstructure of MP gel also exhibited irregular aggregation, resulting in a decline in protein digestibility. In addition, lard oxidation (2 h) had a positive effect on maintaining gel stability during storage.

Effect of glyceryl monopalmitate on the gelatinization, rheological and retrogradation properties of Japonica rice starch.

Starch-based food is easy to retrograde during cold storage after gelatinization, which leads to quality fission and a relatively short shelf life. Some lipids can effectively enhance the storage stability of starch gels by the formation of starch-lipid complexes. The present study aimed to investigate the effects of glyceryl monopalmitate (GMP) on gelatinization, rheological and retrogradation properties of Japonica rice starch (JS) at different conditions and to analyze the correlation between the physical-chemical properties and structural characteristics of the JS-GMP complex. The addition of GMP to JS could retard the process of starch gelatinization through forming JS-GMP complexes. The resulting JS-GMP pastes were typical pseudoplastic fluids with shear thinning, and their solid-like properties were prominent (tan δ < 1). In addition, the retrogradation of JS-GMP complex was more inhibited during storage at -18 than at 4 °C. The added amount of GMP was negatively and highly associated with the minimum viscosity, consistency coefficient, hardness and elasticity, whereas it was positively and highly correlated with the breakdown value, fluid characteristic index and relative crystallinity. The relative crystallinity of JS was affected by GMP in an approximate dose-dependent manner. The addition of GMP can influence the gelatinization properties, rheological properties and retrogradation characteristics of JS, and the formation of JS-GMP complex could improve the quality and storage stability of starch gel, which provides ideas for the quality control of starch-based food. © 2024 Society of Chemical Industry.

Impact of κ-Carrageenan on the Freshwater Mussel (Solenaia oleivora) Protein Emulsion Gels: Gel Formation, Stability, and Curcumin Delivery.

Protein-based emulsion gels are an ideal delivery system due to their unique structure, remarkable encapsulation efficiency, and tunable digestive behavior. Freshwater mussel (Solenaia oleivora) protein isolate (SoPI), an emerging sustainable protein with high nutritional value, possesses unique value in the development of functional foods. Herein, composite emulsion gels were fabricated with SoPI and κ-carrageenan (κ-CG) for the delivery of curcumin. SoPI/κ-CG stabilized emulsions possessed a high encapsulation efficiency of curcumin with a value of around 95%. The addition of κ-CG above 0.50% facilitated the emulsion gel formation and significantly improved the gel strength with 1326 g. Furthermore, the storage and digestive stability of curcumin were significantly improved as the κ-CG concentration increased. At 1.50% κ-CG, around 80% and 90% curcumin remained after 21-day storage at 45 °C and the 6 h in vitro gastrointestinal digestion, respectively. The addition of 0.50% κ-CG obtained the highest bioaccessibility of curcumin (~60%). This study illustrated the potential of SoPI emulsion gels as a carrier for stabilizing and delivering hydrophobic polyphenols.

Mechanical (ball milling) activation to regulate microstructure of κ-carrageenan and improve freeze-thaw stability of κ-carrageenan gels and κ-carrageenan-based emulsion gels

To expand the wide range of applications of κ-carrageenan in the food and biomedical fields, we have physically modified the carrageenan and focused on its freeze-thaw stability. In this study, κ-carrageenan (KC) was modified by mechanically activated to prepare wet ball milling κ-carrageenan (WMKC), and its properties were determined. The research results indicate that mechanical activation helps improve the freeze-thaw stability of KC gels and enables KC to better maintain its gel network structure during the freeze-thaw process. These phenomena are related to the effects of mechanical activation on the particle morphology, molecular structure, molecular interactions, and moisture migration of κ-carrageenan. The particle morphology images demonstrated that the WMKC particles exhibited a more irregular surface, which facilitated greater penetration of water molecules into the interior of the κ-carrageenan particles. Furthermore, the results of molecular structure and molecular interaction analyses showed that mechanical activation resulted in the removal of sulfate groups from the κ-carrageenan molecular chain. This resulted in more free -OH being exposed on the molecular chain, which in turn provided more binding sites for KC molecules with water molecules. Low-field nuclear magnetic resonance (LF-NMR) results also proved that WMKC could better maintain the binding with water molecules during the freeze-thaw process. A better combination of WMKC molecules and water molecules can significantly diminish the irreversible damage to the gel network structure of WMKC during the freeze-thaw process, thereby effectively enhancing the freeze-thaw stability of WMKC. In addition, we further used WMKC as the gel matrix and investigated that the freeze-thaw stability of the WMKC-based emulsion gel was optimal when the mechanical activation duration was 3h, which well meets the demand of κ-carrageenan emulsion gels in the frozen food industry.

Fabrication of Ag Nanoparticle-Embedded Covalent Organic Frameworks for Oil Gel with Long-Term Stability and High Lubrication Performance.

In previous reports, covalent organic frameworks (COFs) have demonstrated significant potential as lubricant additives. Herein, we embedded Ag nanoparticles in the DT-COF (polycondensation polymer of 2,5-dihydroxyterephthalaldehyde and 4,4',4″-(1,3,5-triazine-2,4,6-triyl) trianiline) matrix via the ball milling method and utilized this composite (Ag@DT-COF) as an additive for supermolecule oil gel. The low molecular weight gelator effectively mitigates the dispersion challenges of COFs in lubricant oil, while the embedded Ag nanoparticles enhance the repairing effect and antipressure performance of the lubricant. The resulting Ag@DT-COF gel exhibits a reduction in the average friction coefficient and wear volume of base oil by 46.0% and 87.5%, respectively, and increases the load-carrying capacity to 750 N. The remarkable tribological properties are attributed to the easy adsorption of DT-COF, antiwear characteristic of Ag nanoparticles, and the gelator that ensures the long-term stability of oil gel.

Stabilization of gels and emulsions in the ternary water/eugenol/poloxamer 407-system: Physicochemical characterization and potential application as encapsulation platforms

The ternary system water/eugenol/poloxamer 407 can form a variety of phases that are strongly influenced by the mixture composition and the thermal history of the system. In this study, we investigated the stabilization of emulsion and gel-like systems in which eugenol is encapsulated in a poloxamer 407 matrix. Our results reveal the complex interplay between poloxamer 407 and eugenol compositions in the stabilization single-phase systems at 25ºC. Increasing concentrations of poloxamer were found to incorporate higher amounts of eugenol into emulsion-like dispersions, effectively preventing coalescence and Ostwald ripening. However, high concentrations of poloxamer 407 induced gelation of these dispersions, resulting in eugenol-loaded poloxamer 407 gels. The thermal annealing of the emulsions at 65°C for 1 h followed by equilibration at room temperature allows the extension of the compositional range for the formation of homogeneous single-phase systems providing a strategy to modulate the phase diagram of the ternary system. Additionally, the encapsulation of hydrophobic pesticides in gel-like matrices was investigated, showing uniform distribution and consistent loading capacity (approximately 0.70 % w/w) across different pesticides which may contribute to facilitate the environmental distribution and efficacy of the encapsulated molecules. This research highlights the potential of eugenol/poloxamer 407-based systems as an environmentally friendly platform for the encapsulation and delivery of hydrophobic active molecules, offering a versatile solution for various applications.

Effects of eggshell powder emulsion gel on the oxidative stability and sustained-release effect of lavender essential oil

This study aimed to develop a new type of eggshell powder (EP) emulsion gels for improving the antioxidant ability and sustained release effect of lavender essential oil (LEO). The effects of EP addition on the physicochemical, structural properties, oxidative stability, and sustained-release performance of the emulsion gels were investigated. The results showed that with the increase of EP addition (0–1 %), the gel strength initially increased and then decreased. The emulsion gel with 1 % EP had better freeze-thaw stability (36.77 %), thermal stability (78.63 °C), and water holding capacity (96.57 %). Moreover, the micromorphology results indicated that the EP-ovalbumin (OVA)-konjac glucomannan (KGM) complex showed a connected filamentous network structure, and the emulsion gel with 1 % EP addition had the most uniform and densest network structure. Furthermore, the EP emulsion gel had the highest free sulfhydryl content and hydrophobic interaction, and LEO exhibited the best antioxidant and sustained-release properties at this time. In conclusion, the findings demonstrated the potential of eggshell powder to enhance emulsion gel stability, which could improve the high-value utilization of egg by-products.

Research and Application of Compound Movable Gel Plugging Agent Suitable for Gasi Oilfield

Abstract In order to meet the water plugging requirements of high salinity reservoirs at different temperatures, we developed three kinds of movable gel plugging and regulating agent by using salt resistant polymer as the main agent, organic chromium and organic aldehyde as the cross-linking agent, supplemented by organic stabilizers and reinforcing agents. Namely, low, medium and high-temperature and high-salinity composite movable gel plugging and regulating agent, and the formulas are 0.4% YG-100 + 0.1% YG-107,0.4% YG-100 + 0.15% YG-107+0.8% YG-103,0.4% YG-100+0.15% YG-107+0.8% YG-103 respectively. The gelling performance, thermal stability and salt resistance of the composite movable gel are evaluated. The results showed the suitable temperature is 40~126 °C, and the salinity of formation water is 260000mg/L. Seven well groups were implemented on site, and the oil pressure in the water wells generally increased. Water channeling was controlled to a certain extent, and the comprehensive water content decreased from 90.5% to 85.1%, a decrease of 5.4%. The cumulative increase in oil production was 3164 tons, and a good oil increase effect was observed.

Effect of cooling rate on the retrogradation properties and quality of refrigerated dry-steamed fried rice

The cooling rate is an important factor affecting the quality of refrigerated fried rice. The effect of the cooling rate (0.16°C/min, 0.78°C/min, 1.66°C/min) on the retrogradation properties of dry-steamed fried rice during the refrigeration period (0-3 d) was investigated. The increased cooling rate from 0.16 to 1.66°C/min led to a weakening of stability of the fried rice gel and an increase in the loss of moisture content of the fried rice from 0.86% to 7.11% after 3 d of refrigeration. The cooling rate of 0.78°C/min slowed the increase in hardness of fried rice and resulted in a lower short-range ordering (0.85) as well as the least increase in relative crystallinity (9.51%) after 3 d of refrigeration. However, a cooling rate of 1.66°C/min resulted in a crispy texture and the worst sensory quality of the fried rice after reheating. Both the 0.16°C/min and the 1.66°C/min cooling rates increased the viscosity and reduced the thermal stability of the fried rice paste system. In contrast, a cooling rate of 0.78°C/min is the most suitable cooling rate for refrigerated dry-steamed fried rice. These results will be of guiding significance for regulating the regrowth of dry-steamed fried rice by changing the cooling rate.

Extraction technology determines the properties of bamboo shoots dietary fiber concentrate and its application in chicken mince gels: Systematic analysis

This study investigated how physical, chemical, and enzymatic extraction technologies affected the physicochemical properties of bamboo shoot insoluble dietary fiber (IDF). Additionally, the effects of IDF extracted by these techniques on the gel properties, water retention, microstructure, and digestibility of chicken mince gels were evaluated. Results showed that IDFs extracted by physical (P-IDF), chemical (C-IDF), and enzymatic (E-IDF) exhibited a typical cellulose polysaccharide structure and strong water and oil retention capabilities, with the highest values reaching 14.18 g/g and 6.74 g/g, respectively. Compared to P-IDF, C-IDF and E-IDF displayed a rougher porous structure and stronger adsorption capacities for glucose (409.91 mg/g and 604.95 mg/g), cholesterol (54.46 mg/g and 64.06 mg/g), sodium cholate, and nitrite. The addition of IDF improved the water retention, water stability, texture, and rheological properties of chicken mince gels, and had no negative effect on the digestion of chicken mince proteins. On the one hand, the hydrophilic groups exposed in IDF absorb water and fill the gel networks, reducing the formation of water channels in the gel and improving water stability. Furthermore, the hydrophilic groups on the glucose unit that makes up the IDF interacts with the proteins through the hydrogen bond and the transformation of protein β-structure to α-structure, promoting the formation of gel network structure and improving gel texture and rheological properties. E-IDF and C-IDF showed better overall gel performances, but E-IDF had better dry matter digestibility, protein digestibility, and gastrointestinal digestive effects. Therefore, IDF prepared by enzymatic hydrolysis is more suitable for chicken mince processing.

Enhancement of the formation and stability of low-fat Pickering emulsion gels stabilized with egg yolk granules-chitosan complex: Insights into the development of mayonnaise substitutes

This study employed egg yolk granules (EYG) in combination with chitosan (CS) to evaluate the feasibility of constructing low-fat Pickering emulsion gels and investigated the properties of emulsion gels with different oil volume fractions (0–50 %) to address the stability issue. The results showed that the self-supporting structure of the emulsion gels gradually increased at 0–40 % oil phase, and the oil droplet sizes were all smaller than 10 μm. However, when the oil phase reached 50 %, the emulsion showed water-oil phase separation. The addition of oil modified the state and movement of water molecules in the emulsion system, which in turn affected the water and oil loss rates. Notably, the emulsion gels exhibited similar rheological and textural characteristics to mayonnaise at 30 % oil phase. Furthermore, the emulsion gels demonstrated promising centrifugation and freeze-thaw stability. This study suggests an innovative and efficient approach to low-fat mayonnaise substitution with consistent quality.

Thermorheological properties and structural characteristics of soy and pumpkin seed protein blends for high-moisture meat analogs

This study explored the effects of soy protein isolate (SPI) and pumpkin seed protein concentrate (PSC) blends on the thermorheological properties and microstructure of high-moisture meat analogs. Using a Discovery Hybrid Rheometer, we observed that increasing PSC content weakened SPI network formation, resulting in decreased gel stability and a more porous, less aligned structure. Microstructural analyses (FE-SEM and FT-IR) revealed a correlation between protein network disruption and increased PSC content. Additionally, higher PSC levels reduced overall bonding (ionic, hydrogen, hydrophobic, disulfide), modifying the texture and softening the gel while retaining solid-like characteristics essential for replicating meat textures. Although full high-moisture extrusion conditions were not replicated, the observed trends offer valuable insights into texture development for meat substitutes. Future research using a closed-system rheometer is required to validate these findings and improve precision.

Inflammatory regulation of squid cartilage gelatin with different molecular weights for treatment of chronic wounds in diabetes

Squid, as a very important economic marine species, accounts for 5 % of the total catch of fish and cephalopods. The waste from the processing process of squid can be used for collagen extraction, which has great application value in the field of biomedical materials. Here, we obtained squid cartilage gelatin (SCG) with different molecular weights by adjusti.ng the reaction conditions and used for the treatment of chronic wounds in diabetes. SCG extracted at low temperatures and short heating times demonstrated a more intact structure, higher molecular weight, and superior gel stability. Based on cell study and transcriptome analysis, SCG with high molecular weight significantly promoted cell adhesion, because it provided more contact sites for cells, whereas small molecules of SCG could directly reduce inflammation. Animal studies have demonstrated that SCG significantly promotes diabetic wound healing as evidenced by reducing inflammation, inducing vascular regeneration, promoting tissue growth, re-epithelialization, collagen deposition and remodeling. This study elucidated the immunoregulatory mechanisms of SCG with different molecular weights, and validated its potential application in chronic wound healing in diabetes.