Stability Of Gels Research Articles

Prevention of postoperative adhesion with a colloidal gel based on decyl group-modified Alaska pollock gelatin microparticles

Postoperative adhesion, bonding of the abdominal wall to damaged organs, causes severe complications after abdominal surgery. Despite the availability of physical barriers (i.e., solutions, films, and hydrogels), adhesion prevention materials that are a single-substance system with stability in wet tissue and ease of use have not been reported. Here, we report a microparticle based, sprayable adhesion prevention material comprising decyl group modified Alaska pollock gelatin (C10-ApGltn). C10-ApGltn microparticles (C10-MPs) were prepared by a coacervation method, freeze drying, and thermal crosslinking. The C10-MPs adhered to and formed a colloidal gel layer on intestinal serosal tissue by hydration without any crosslinking agents. After hydration of the C10-MPs, the resulting colloidal gel layer did not adhere to other tissues. Additionally, the C10-MP colloidal gel layer formed on the stomach serosal tissue showed stability when submersed in saline for 2 days. The colloidal gel layer also showed tissue followability. An in vivo rat adhesion model revealed that C10-MP colloidal gel layer on the cecum and abdominal wall defects effectively reduced postoperative adhesion and induced tissue remodeling, including re-mesothelialization. Therefore, C10-MPs are a potential anti-adhesion material for preventing postoperative adhesion. Statement of significanceWe evaluated the postoperative adhesion prevention ability of a colloidal gel based on decyl group modified Alaska pollock gelatin (ApGltn) microparticles (C10-MPs). These microparticles are sprayable and form a colloidal gel with only hydration on the gastrointestinal tissue. We revealed that the modification of the decyl group into ApGltn improved the stability of C10-MP colloidal gel on the tissue by hydrophobic interaction in the in-vitro experiments. The gel prevented postoperative adhesion by being a physical barrier in the in-vivo rat adhesion model.

Effects of quinoa protein Pickering emulsion on the properties, structure and intermolecular interactions of myofibrillar protein gel

The effects of quinoa protein Pickering emulsion (QPE) on the gel properties, protein structure and intermolecular interactions of myofibrillar protein (MP) gels were studied. Compared with the MP gels without QPE, the MP gels with 5.0%-7.5% added QPE showed significant increasing trends in storage modulus (G′), whiteness, gel strength and water holding capacity (WHC). The content of disulfide bonds in the gel increased with the addition of QPE and the disulfide bond conformation changed from gauche-gauche-gauche to gauche-gauche-trans. Moreover, the increase of hydrogen bonds after QPE addition confirmed the transformation from α-helix to β-sheet, as β-sheet structure was stabilized by interchain hydrogen bonds. The added QPE also enhanced the hydrophobic interaction and electrostatic interaction of MP gels. To conclude, the addition of 5.0%–7.5% QPE improved the intermolecular interactions and the structure stability of MP gels, and enhanced the gelation and WHC of MP gels.

Gel properties of blue round scad (Decapterus maruadsi) mince as influenced by the addition of egg white powder.

The use of egg white powder (EWP) to enhance the physicochemical properties, molecular structure, and thermal stability of Decapterus maruadsi mince gels was investigated. The thermal stability was analyzed by adding spray-dried EWP (0, 0.2, 0.4, 0.6, 0.8, and 1%) to the mince, and mince gels were prepared to study the changes in their fracture constant, water distribution, microstructure, and protein conformation of mince gels. In addition, the stress-strain curve of the EWP-mince gel was measured to obtain its compressive modulus (E). The formation of the mince gel was promoted by EWP, and the whiteness, fracture constant, water-holding capacity (WHC), and immobilized water were all enhanced. At 0.8% addition of EWP, the fracture constant increased from 176.715 ± 2.463 N/m to 348.631 ± 3.144 N/m (p < .05), which was a nearly twofold improvement. Additionally, the WHC increased from 75.21% to 79.99%, and the percentage of immobilized water increased from 94.03% to 94.91%. The EWP-mince gel network structure was the most uniform and dense, and there were increases in hydrogen bonds, disulfide bonds, β-sheets, and β-turns in mince gels, as well as the storage modulus (G') and enthalpy (ΔH). In contrast to the control group, the relative content of α-helixes decreased from 53.34% to 37.09% and transformed into other secondary structures, and the bulk water and cooking loss also decreased to 2.41% and 8.51%, respectively. Consequently, EWP effectively improved the quality of mince products, and the effect was most apparent when 0.8% was added.

The Effect of HPMC Concentration as a Gelling Agent on Color Stability of Copigmented Blush Gel Extract of Purple Sweet (Ipomoea Batatas (L.) Lam.)

Purple sweet potato contains anthocyanin pigments that can be used as natural dyes. However, the use of anthocyanins as dyes has less stable properties. Anthocyanin stability can be increased by the addition of copigments. Copigment that can be used is apple extract at pH 4.6. In this study, a blush was made. One of the blush dosage forms that can be made is gel. Blush gel can provide a cool feeling, easy to wash, soft, and not sticky on the skin. In the creation of gels, the gelling agent is one of the components that affect the characteristics of gel preparations. HPMC is a gelling agent used in the manufacture of blush gel preparations. This study aims to determine the effect of increasing the concentration of HPMC as a gelling agent on the color stability of the copigmented purple sweet potato extract blush gel. The preparations were made in 3 formulas with varying concentrations of gelling agent (F1) 1%, (F2) 1.5%, and (F3) 2%. The evaluation carried out included testing the physical characteristics of the gel, namely organoleptic test, pH test, dispersion test, phase separation test, color stability test, and preference test. The results showed that the evaluation of blush gel preparations met the requirements of pharmaceutical standards with the pH test value of blush gel preparations being 4.72 to 5.84 and the spreadability test value being 5.26 cm to 6.48 cm. The results of the color stability test on the three formulas showed that there were significant differences. The increase in the concentration of HPMC as a gelling agent on the color stability of the copigmented purple sweet potato extract blush gel was unstable during 28 days of storage.

Ionic liquids as tools to improve gel formulations containing sparingly soluble phenolic acids

Hydroxycinnamic acids, namely caffeic and p-coumaric acids, have several pharmaceutical and cosmetic applications, but due to their low aqueous solubility, their applicability can be limited. Ionic liquids (ILs) have been shown to be a valuable tool to improve the solubility and assist in the incorporation of various phenolic compounds into delivery systems. Thus, this work aims to evaluate the impact of incorporating three choline-based ILs, namely (2-hydroxyethyl)-trimethylammonium-L-phenylalanine [Cho][Phe], (2-hydroxyethyl)-trimethylammonium-L-glutamate [Cho][Glu] and (2-hydroxyethyl)-trimethylammonium-glycinate [Cho][Gly], into an aqueous gel formulation containing the poorly soluble caffeic and p-coumaric acids. The results obtained confirm that the ILs not only increase the drug solubility, but also allow higher amounts of both studied drugs to be incorporated into the gels, without interfering with the stability of the aqueous gels. Moreover, the ILs altered the fluidity of the gels, both in the absence and presence of both phenolic acids, as they increase the viscosity of the formulations, contributing to higher flow resistance of the gel, which may be better accepted by the consumer. Keywords: Ionic liquids; Hydroxycinnamic acids; Poorly soluble drugs; Gels; Increased Viscosity

From Precision Colloidal Hybrid Materials to Advanced Functional Assemblies.

ConspectusThe concept of colloids encompasses a wide range of isotropic and anisotropic particles with diverse sizes, shapes, and functions from synthetic nanoparticles, nanorods, and nanosheets to functional biological units. They are addressed in materials science for various functions, while they are ubiquitous in the biological world for multiple functions. A large variety of synthetic colloids have been researched due to their scientific and technological importance; still they characteristically suffer from finite size distributions, imperfect shapes and interactions, and not fully engineered functions. This contrasts with biological colloids that offer precision in their size, shape, and functionality. Materials science has searched for inspiration from the biological world to allow structural control by self-assembly and hierarchy and to identify novel routes for combinations of functions in bio-inspiration.Herein, we first discuss different approaches for highly defined structural control of technically relevant synthetic colloids based on guided assemblies of biological motifs. First, we describe how polydisperse nanoparticles can be assembled within hollow protein cages to allow well-defined assemblies and hierarchical packings. Another approach relies on DNA nanotechnology-based assemblies, where engineered DNA structures allow programmed assembly. Then we will discuss synthetic colloids that have either particularly narrow size dispersity or even atomically precise structures for new assemblies and potential functions. Such colloids can have well-defined packings for membranes allowing high modulus. They can be switchable using light-responsive moieties, and they can initiate packing of larger assemblies of different geometrical shapes. The emphasis is on atomically defined nanoclusters that allow well-defined assemblies by supramolecular interactions, such as directional hydrogen bonding. Finally, we will discuss stimulus-responsive colloids for new functions, even toward complex responsive functions inspired by life. Therein, stimulus-responsive materials inspired by biological learning could allow the next generation of such materials. Classical conditioning is among the simplest biological learning concepts, requiring two stimuli and triggerable memory. Therein we use thermoresponsive hydrogels with plasmonic gold nanoparticles and a spiropyran photoacid as a model. Heating is the unconditioned stimulus leading to melting of the thermoresponsive gel, whereas light (at a specified wavelength) originally leads to reduced pH without plasmonic or structural changes because of steric gel stabilization. Under heat-induced gel melting, light results in pH-decrease and chain-like aggregation of the gold nanoparticles, allowing a new plasmonic response. Thus, simultaneous heating and light irradiation allow conditioning for a newly derived stimulus, where the logic diagram is analogous to Pavlovian conditioning. The shown assemblies demonstrate the different functionalities achievable using colloids when the sizes and the dispersity are controlled.

FEATURES OF PUBLIC DEBT REGULATION IN GEORGIA: CURRENT CIRCUMSTANCES AND MODERN CHALLENGES

The article addresses the issues of ensuring the exchange rate stability of GEL - the national currency of our country and effective management and regulation of public debt as well as attaches weight to the mechanisms for overcoming the challenges of economic development in the country and to the selection and use of flexible tools. The article highlights the efforts of the leaders of the government and the National Bank of the country in developing and implementing the optimal macroeconomic policies, as well as in maintaining monetary policy stability and achieving sustainable economic development. Furthermore, considerable attention is given to the GEL exchange rate not only against to major currencies - the USD or the euro - but also to the currencies of the other partner countries of Georgia. The article analyzes the dynamics of changes in the GEL exchange rate against the currencies of partner countries, based on the statistical data of the National Bank of Georgia. Factors influencing both effective nominal and real exchange rates as well as government domestic and external debt are also assessed at different time intervals. Thus, the purpose of this article is to identify the issues related to the management and regulation of public debt based on the analysis of the dynamics and structure of public debt of Georgia, as well as to study the factors that have a positive and negative effect on them. This article aims to identify the issues related to the management and regulation of public debt obligations, on the basis of public debt sustainability analysis. The article, on the basis of statistical data, analyzes the dynamics and structure of public debt in 2010-2020. The problematic issues in the financial and monetary system are also identified and their determinants are investigated. Recommendations have been developed to reduce the debt burden and overcome the negative consequences caused by them. Based on the analysis of the economic situation in Georgia and the dynamics of the exchange rate, the recommendations for stabilizing the exchange rate of the financial sector, effective management of public debt and achieving sustainable economic growth have been developed in this article. Subject and object of research. The subject of the article's research is to identify problems related to the fluctuation of the Georgian national currency exchange rate and public debt regulation. While the object of the article is monetary policy that have been developed and implemented by the National Bank of Georgia and the Ministry of Finance of Georgia. Research methods. Relevant scientific literature as well as statistical data from the National Bank of Georgia, the Ministry of Finance and the National Statistics Office of Georgia were found at the initial stage of the research. In addition, the studies and articles by Georgian and foreign scholars on public debt issues and the materials of the International Monetary Fund were used. The scientific value of the article. The article analyzes the dynamics and structure of the GEL exchange rate and public debt in 2010-2020 based on the statistical data of Geostat and the Ministry of Finance of Georgia. Problematic issues in the field of finance and monetary-credit have been identified and their causes have been investigated. The recommendations have been developed to alleviate the debt burden of Georgia and overcome the negative consequences caused by them. Based on the analysis of the economic situation in Georgia and the dynamics of the GEL exchange rate, the article develops recommendations for improving the financial sector, stabilizing the exchange rate and ensuring effective public debt management and sustainable economic growth. It should also be noted that, the article addresses and assesses the approaches of the leaders of Government of Georgia and the National Bank to ensuring the formation and improvement of a stable macroeconomic environment. The role of monetary policy in ensuring the sustainable development of the economy is revealed. In addition, the mistakes in exchange rate regulation and public debt management are also identified and assessed. The article substantiates the crucial role of ensuring the stability of the GEL exchange rate in achieving economic growth. Besides, reviewing the GEL exchange rate is important not only against the USD, but also against the currencies of other trading partner countries. Accordingly, the paper, based on the statistical data, also analyzes the dynamics of changes in the GEL exchange rate against the currencies of partner countries. The article also analyzes the key factors affecting both effective nominal and real exchange rates, as well as domestic and external debt at different time intervals.

Poly (N-Vinylcaprolactam-Grafted-Sodium Alginate) Based Injectable pH/Thermo Responsive In Situ Forming Depot Hydrogels for Prolonged Controlled Anticancer Drug Delivery; In Vitro, In Vivo Characterization and Toxicity Evaluation.

This study was aimed to develop novel in situ forming gels based on N-vinylcaprolactam, sodium alginate, and N,N-methylenebisacrylamide. The in situ Poly (NVRCL-g-NaAlg) gels were developed using the cold and free radical polymerization method. The structure formation, thermal stability, and porous nature of gels was confirmed by FTIR, NMR, DSC, TGA, and SEM. The tunable gelation temperature was evaluated by tube titling and rheological analysis. Optical transmittance showed that all formulations demonstrated phase transition around 33 °C. The swelling and release profile showed that gels offered maximum swelling and controlled 5-FU release at 25 °C and pH (7.4), owing to a relaxed state. Porosity and mesh size showed an effect on swelling and drug release. The in vitro degradation profile demonstrated a controlled degradation rate. An MTT assay confirmed that formulations are safe tested against Vero cells. In vitro cytotoxicity showed that 5-FU loaded gels have controlled cytotoxic potential against HeLa and MCF-7 cells (IC50 = 39.91 µg/mL and 46.82 µg/mL) compared to free 5-FU (IC50 = 50.52 µg/mL and 53.58 µg/mL). Histopathological study demonstrated no harmful effects of gels on major organs. The in vivo bioavailability in rabbits showed a controlled release in gel form (Cmax, 1433.59 ± 45.09 ng/mL) compared to a free drug (Cmax, 2263.31 ± 13.36 ng/mL) after the subcutaneous injection.

Gelatin-lecithin-F127 gel mediated self-assembly of curcumin vesicles for enhanced wound healing

Curcumin, a principal component of Curcuma longa, has a long history of being used topically for wound healing. However, poor aqueous solubility of curcumin leads to poor topical absorption. Recently, gelatin based gel has been reported to overcome this issue. However, the release of curcumin from gelatin gel in the bioavailable or easily absorbable form is still a challenge. The present study reports the development of a composite gel prepared from gelatin, F127 and lecithin using temperature dependant gelation and loading of curcumin within it. Notably, the composite gel facilitated the release of curcumin entrapped within vesicles of ~400 nm size. Further, the composite gel exhibited increase in the storage modulus or gel strength, stability, pore size and hydrophobicity as compared to only gelatin gel. Finally, wound healing assay in murine model indicated that curcumin delivered through composite gel showed a significantly faster healing as compared to that delivered through organic solvent. This was also validated by histopathological and biochemical analysis showing better epithelization and collagen synthesis in the group dressed with curcumin containing composite gel. In conclusion, composite gel facilitated the release of bioavailable or easily absorbable curcumin which in turn enhanced the wound healing.

Self-Assembly of Alkylamido Isophthalic Acids toward the Design of a Supergelator: Phase-Selective Gelation and Dye Adsorption.

A new series of 5-alkylamido isophthalic acid (ISA) derivatives with varying single and twin alkyl chain lengths were designed and synthesized as potential supramolecular organogelators. 5-alkylamido ISAs with linear or branched alkyl tail-groups of different lengths were effective gelators for low polarity solvents. In particular, among the presented series, a derivative with a branched, 24 carbon atom tail-group behaves as a “supergelator” with up to twenty organic solvents forming gels that are highly stable over time. The gelation behavior was analyzed using Hansen solubility parameters, and the thermal stability and viscoelastic properties of select gels were characterized. Microscopy, spectroscopy, powder X-ray diffraction, and computer modeling studies were consistent with a hierarchical self-assembly process involving the formation of cyclic H-bonded hexamers via the ISA carboxylic acid groups, which stack into elementary fibers stabilized by H-bonding of the amide linker groups and π–π stacking of the aromatic groups. These new nanomaterials exhibited potential for the phase-selective gelation of oil from oil–water mixtures and dye uptake from contaminated water. The work expands upon the design and synthesis of supramolecular self-assembled nanomaterials and their application in water purification/remediation.

Synthesis of low-molecular-weight gel with tunable gel-sol transition temperature for thermo-sensitive drug controlled release

A phenylboronic acid (PBA)-based gelator was synthesized, and host-guest low-molecular-weight gel (LMWG) was fabricated by the inclusion complexes (ICs) of the gelator and β-cyclodextrin (β-CD). Translucent gel consisting of nanofiber or nanobelt (60–430 nm wide) was obtained with low critical gelation concentration (CGC) of 2.9 mg/mL (0.36 wt%). The gel-sol transition temperature (Tgel) of the IC gel could be regulated from 37.5 °C to 44.9 °C by different inclusion ratio of gelator and β-CD. And the rheological properties exhibited the rapid recovery of the sol, the gel was re-formed in 2.5 min at 37 °C, and fully restored the initial storage modulus (G’). This tunable gel-sol-gel transition has been applied in thermo-sensitive controlled release of naproxen for tumor fever. Naproxen (16.7 μg•mL−1•min−1) was released from the drug-loaded gel (Loading Efficiency = 8.3%) when heated at 38.5 °C, and the release process terminated when the sol reconverted into gel at 37 °C, and it was achieved again when the gel converted to sol at 38.5 °C. Both the blank and drug-loaded gel could gellated rapidly after subcutaneous injection. The stability of gel was greatly improved to 102 h by the salts' induce, and the gel-sol transition was also controlled by vary kinds of salts and salt concentration.

Water Control with Gels Based on Synthetic Polymers under Extreme Conditions in Oil Wells

AbstractA bibliographic review of research works dealing with gels based on synthetic polymers and their application in water control under harsh conditions was compiled. The extreme conditions were defined to be above 100 °C with 100 000 ppm of total dissolved solids, including divalent ions. Works describing laboratory experiments and oilfield implementations were also considered. According to current literature, some gels based on synthetic polymers have displayed desirable properties for water control, but in many cases, research is still at laboratory level. Therefore, further studies are required to understand the mode of action and stability of gels and polymers submitted to hard conditions in order to produce high‐performance prototypes.

Hyaluronic acid-g-PPG and PEG-PPG-PEG hybrid thermogel for prolonged gel stability and sustained drug release

Hyaluronic acid-graft-poly(propylene glycol) (HA-g-PPG) was prepared to induce hydrophobic interactions between HA-g-PPG and F127 PPGs (poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol)) and consequent increases in gel stability of F127 gel. Molecular weights of 340, 1000, and 2500 Da were used for PPG, and grafting ratios of HA-g-PPG varied over 3%, 12%, and 50%. Using rheology measurements, 1H NMR spectra, lower critical solution temperature measurements, dynamic light scattering, and transmission electron spectroscopy, hydrophobic crosslinking and intermicellar bridge formation were suggested in the aqueous HA-g-PPG/F127 hybrid solutions. In particular, the gel stability of the HA-g-PPG/F127 hybrid thermogel increased from 2 days (F127 only) to 6 days, thus the hybrid thermogel can provide longer delivery of an incorporated drug. The HA-g-PPG/F127 thermogel exhibited tissue compatibility in the subcutaneous layer of rats. The protein drug release from the gel indicated that interactions between negative charged HA-g-PPG and positive charged drug (calcitonin) reduced initial burst release.

Ultrasonic pretreatment improves the gelation properties of low-salt Penaeus vannamei (Litopenaeus vannamei) surimi

The effects of different ultrasonic pretreatments (120–600 W, 20 min; 360 W, 10–30 min) on the gel properties of shrimp surimi were investigated. Gel properties and protein functional properties were analysed to clarify the mechanism of action of ultrasound. The gel strength, water holding capacity and surface hydrophobicity of shrimp surimi gel increased initially and then decreased with the increase in ultrasound power or time, but the change in total sulfhydryl content showed the opposite trend, which indicated that proper ultrasound pretreatment could improve the gel properties of shrimp surimi, expand the protein to a greater extent and expose more SH groups and hydrophobic groups. According to scanning electron microscopy observation, ultrasound made shrimp surimi gel form a denser gel network. Fourier transform infrared analysis indicated that the α-helix content in shrimp surimi gel decreased initially and then increased with the increase of in ultrasound power or time, whereas the change in β-sheet content showed the opposite trend. And the protein was the most stable in 360 W/20 min pretreatment. SDS-PAGE patterns showed that proper ultrasound inhibited the degradation of actin and troponin C. In addition, dynamic rheology illustrated that the G′ values of the ultrasonic pretreatment group were higher than that of the control group, indicating that ultrasound could improve the elasticity and stability of shrimp surimi gel. The results suggested that the shrimp surimi gel pretreated by 360 W/20 min ultrasound showed the best gel properties. Furthermore, the correlation between the indexes affecting the properties of the gel was analyzed. This study provides a new technical means to improve the gel properties of shrimp surimi.

Preparation and Mechanism of Stability for High-Temperature and High-Salinity Gels

Summary By using an acrylamide (AM)-acrylamide propyl sulfonate (AMPS) copolymer crosslinked with hydroquinone (HQ) and hexamethylenetetramine (HMTA), a stable gel was prepared at 150℃ in simulated brine with a salinity of 25×104 mg/L. The gelation time, strength, and thermal stability of gel were investigated, and the results indicated that the dosage of the crosslinker was the key factor controlling the stability and gelation time of gel. When the polymer concentration was more than 0.7 wt% and the concentrations of HQ and HMTA were more than 0.2 wt%, respectively, a gel aged under high temperature and high salinity for 180 days could be obtained, but its gelation time was short and could be extended by adding lauramidopropyl hydroxy sulfobetaine (LHSB). When the crosslinker concentration was low, the gel would exhibit syneresis problems after aging at 150℃. Cryo-scanning electron microscopy (cryo-SEM), 13C nuclear magnetic resonance (13C-NMR), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses showed that the presence of AMPS in the crosslinked polymer controlled the gel resistance to high temperature and high salinity. Using AM-AMPS copolymer with high AMPS content and regulating the crosslinker concentration can effectively inhibit the intramolecular catalytic hydrolysis of AMPS and enhance the stability of gel. The research results could guide the design and development of gels for conformance control in high-temperature and high-salinity reservoirs.

A laboratory study of self-healing hydrophobic association gels used as lost circulation material

Polymer gels, composed of preformed particle gels and in-situ gels, have generated broad interest in lost circulation control for decades. However, there are some drawbacks to them. The sealing layer formed by preformed particle gels was easily eroded by cyclic drilling fluid. The size of them needs match that of pores or fractures. In-situ gels, forming the expected pill in the correct location is challenging due to short gelation time, poor resident ability, and gel strength. Due to their unique recovery properties after damage, self-healing gels have been extensively researched and applied in the biomedicine field. Their prospect application in oil and gas drilling and development engineering has been investigated. In this article, we used self-healing hydrophobic association gels prepared in our previous paper to study their performance in lost circulation control, which aimed to integrate advantages of preformed particle gels and in-situ gels and abandon their disadvantages. The chemical structure and thermal stability of self-healing hydrophobic association gels were measured by FTIR and TGA, respectively, indicating good thermal stability. The swelling experiments at different temperatures suggested that they could absorb more water with the rise of temperature. The healing performance of self-healing gel particles at different temperatures and pressures showed that they could heal into a whole gel with good strength at 1–6 MPa and 25–80 ℃. Their healing properties were prone to temperature, followed by healing time. Their plugging performance was tested by a high temperature and pressure filter, meaning that the breakthrough pressure of 3% self-healing gel plugging agent was 3.5 MPa at 80 ℃, using a steel model with a fracture width of 1 mm to imitate fracture formation. The microscopic visualization device saw gel particles' plugging and healing process, indicating that they entered the lost circulation channels, formed a sealing layer like preformed particle gels, and healed into gel pill like in-situ gels. Self-healing gels could provide a new approach to controlling lost circulation and have a promising application prospect.

Formation and stability of Pickering emulsion gels by insoluble soy peptide aggregates through hydrophobic modification

In this work, a highly stable food-grade Pickering emulsion gels was successfully prepared by hydrophobically modified insoluble soybean peptide aggregates. The relationships between the surface properties of insoluble soybean peptide aggregates and Pickering emulsion gels characteristics were clarified. After modification, the insoluble soybean peptide aggregates with high surface hydrophobicity had small particle size (377 nm), near-neutral wettability (θo/w = 92°) and strong interfacial adsorption capability. These allowed the modified insoluble soybean peptide aggregates to stabilize the oil-water interface and form continuous network surrounding oil droplets, leading to the formation of stable Pickering emulsion gels. Besides, Pickering emulsion gels prepared by insoluble soybean peptide aggregates with higher surface hydrophobicity had smaller droplet size and higher gel strength, and remained stable even after 60 days of storage. The findings suggest a preferable plant protein particle for the preparation of stable Pickering emulsion gels in food industry.

Preparation, characterization, formation mechanism and stability of allicin-loaded emulsion gel

The processing instability and strong pungent smell limit the use of allicin. To overcome these shortcomings, emulsion gels loaded with allicin were constructed using soybean protein isolate (SPI) and gum Arabic (GA) through ultrasound treatment and transglutaminase (TG) induction. The effect of ultrasonic modification and GA concentration on the physical properties of emulsion gels was investigated, and the protective effect of emulsion gel on allicin was evaluated. The results showed that ultrasonic pretreatment of SPI can significantly improve the water holding capacity, hardness, viscosity, and elasticity modulus of emulsion gels, forming denser homogeneous network structure, and these properties were best when GA concentration was 0.3%. In the process of gel formation, ultrasound can change the spatial structure of protein, the introduction of polysaccharide can enhance the hydrogen bond between molecules, and TG can promote the intramolecular crosslinking, the three worked together to form a gel network. The encapsulation efficiency of the ultrasonic SPI-GA emulsion gel can reach 70.84%, while it was only 26.63% for the SPI emulsion gel. The degradation of allicin was inhibited under strong light and high temperature. This study provides a new idea for the development of functional food rich in allicin.

Utilization of Inferior Green Coffee Bean Oil for Air Freshener Gel

More than 20% of the coffee beans harvested are not traded because they do not pass the sorting. Coffee beans that do not pass the sorting are referred to as inferior green coffee beans (inferior coffee).. The purpose of this study was to determine the combination of inferior coffee oil concentration and gel material that gave the best characteristics as air freshener. This research method is a laboratory experimental method with descriptive analysis. The research stages consisted of preparation of materials and equipment, extraction of inferior coffee with the soxhletation method and making air freshener. The concentration of inferior coffee oil used was control (A0) 1%; (A1); 2% (A2); 4% (A3) and each concentration was added to a formulation consisting of 0.75 grams of carrageenan, 0.5 grams of agar, 0.25 grams of pectin, 0.05 grams of sodium benzoate, 5 grams of propylene glycol and aquadest to adjust the amount to 50 grams. Product testing parameters consist of strength test, gel hardness test, gel stability test, preference test, liquid evaporation test and fragrance resistance test. The results showed that the best air freshener with 4% coffee oil concentration resulted in a gel strength of 482 g/cm2; gel hardness test 1064 g/cm2; gel stability test 2.387%; preference test 2.78; evaporation test is 69.632% and the value of fragrance resistance is 3.003. Keyword: soxhletation, air freshener gel, inferior coffee oil, gel material, extraction

Effects of fish oil on the gel properties and emulsifying stability of myofibrillar proteins: A comparative study of tilapia, hairtail and squid

The objective of this study was to determine the effects of the myofibrillar protein (MP) characteristics from tilapia, hairtails, and squid on gel properties, microstructure, and emulsification stability of surimi gels with increasing concentrations of fish oil (FO). The surface hydrophobicity (38 μg) of the squid MP was significantly lower than that of the tilapia and hairtail (P < 0.05), and its content (21 g/100 g) and emulsification characteristics were significantly higher than those of the tilapia and hairtail (P < 0.05). Combined with the firmer structure of the squid surimi in the microstructure more intuitively indicated FO occupied the void spaces of the squid protein matrix, revealed the interaction between FO and MPs. Moreover, infrared spectroscopy (FT-IR) and texture analysis demonstrated that tilapia MPs had the highest β-sheet (18%) and β-turn (39%) contents and the lowest α-helix (23%) content compared with the hairtail and squid. Contributed to higher gel strength, reflecting the influence of secondary structure of MPs on the texture of surimi. These results further elaborated the effects of MPs’ structure on surimi emulsified FO and the mechanism of FO on surimi gel, which is meaningful for functional surimi production.