Characteristics Of Gels Research Articles

Effect of green tea extract on heat-induced protein interactions and rennet coagulation in milk

The impact of green tea extract (GTE) on heat-induced milk protein interactions and enzymatic coagulation of milk was investigated. GTE addition affected the renneting process, more apparent for heat-treated samples. The enzymatic phase of rennet coagulation was negatively affected by GTE, with a significantly lower amount of κ-casein hydrolysis for intense heat-treated samples. Gel characteristics of raw milk were unaffected by GTE, but mild heat-treated samples with GTE displayed decreased gel firmness and increased water holding capacity compared with control samples. Model studies conducted with purified β-lactoglobulin A and κ-casein revealed that GTE caused a significant impact on interactions between denatured β-lactoglobulin A and κ-casein. Heat-induced large aggregate/complex formation between β-lactoglobulin A and κ-casein in milk samples was not significantly affected, highlighting the importance of the reaction medium. The presence of casein micelles in milk, which are strong candidates for phenolic binding, may ultimately impact protein–protein interactions.

A gelation facility for the preparation of ceramic microspheres

A gelation facility has been commissioned inside a ‘walk-in’ fume hood for producing oxide microspheres through internal gelation process. This facility would serve both as a test bed for optimizing the process parameters and would serve ‘as a prototype’ for the system to be incorporated in a remotely operated facility for the production of (U,Pu) mixed oxide microspheres containing minor actinides. This facility consists of an indigenously designed 1.6 m tall modular glass column with stainless steel modular support structure, oil reservoir with a recirculation pump, resistive heater, double-jacketed feed tank, a controlled pressure transfer facility, a nozzle with an electromagnetic vibrator, cooling stations for broth preparation, mesh belt conveyor, soft gelled spheres collection tray and microsphere washing stations. The design of the glass column has been optimized to avert choking due to aggregation of the microspheres. The latter has been accomplished by arriving at the optimal flow with the help of a simple flow model. This flow model considers the temperature dependence of viscosity and the temperature distribution within the column, experimentally determined by using infrared thermography. The optimal composition of the feed (broth) has been arrived at by using an innovative measurement of the viscosity of the sol and gel during gelation. The innovation in both equipment and method are being reported for the first time. A novel method to quantify the gelation characteristics of sol has been devised and is being reported for the first time.

Effect of Na+ and Ca2+ on the texture, structure and microstructure of composite protein gel of mung bean protein and wheat gluten

To investigate the change of ionic strength on the gel characteristics during the processing of mung bean protein-based foods, the effects of NaCl and CaCl2 at different concentrations (0–0.005 g/mL) on the properties of mung bean protein (MBP) and wheat gluten (WG) composite protein gel were studied. The results showed that low concentration (0.001–0.002 g/mL) could significantly improve the water holding capacity (WHC), storage modulus (G') and texture properties of composite protein gel (MBP/WG), while the surface hydrophobicity (H0) and solubility were significantly decreased (P < 0.05). With the increase of ion concentration, the secondary structures of MBP/WG shifted from α-helix to β-sheet, and the fluorescence spectra also showed fluorescence quenching phenomenon. By analyzing the intermolecular forces of MBP/WG, it was found that with the addition of salt ions, the hydrogen bonds was weakened and the electrostatic interactions, hydrophobic interactions and disulfide bonds were enhanced, which in turn the aggregation behavior of MBP/WG composite protein gel was affected and larger aggregates between the proteins were formed. It could be also demonstrated that the gel network was denser due to the addition of these large aggregates, thus the gel properties of MBP/WG was improved. However, too many salt ions could disrupt the stable network structure of protein gel. This study can provide theoretical support to expand the development of new mung bean protein products.

Mechanical and Sensory Properties of Pulse Gels in the Development of New Plant Based Food

The shift towards healthier and sustainable food consumption requires a greater variety of plant-based products. This study aimed to determine how the mechanical and sensory properties of three different pulse gels (chickpea, lentil, or red lentil flour) vary with the ingredients (flour, oil, lemon, and salt content). All pulse flours were able to form self-standing gels. Mechanical properties varied with the pulse type and with the formulation differently depending on the pulse. For all pulses, the hardness and stiffness increased with the flour content and decreased with salt. They decreased with lemon in chickpea gels and increased with oil content in the red lentil gel. The Flash Profile technique provided distinctive sensory characteristics of each pulse gel. The red lentil gels were homogeneous, creamy, and compact. The chickpea gels were also compact, but harder. Lentil flour resulted in rough and sandy gels. For the three pulses, including oil and lemon reduced pulse flavors and increased sour taste. The results of this study give insights into the suitability of pulse gels to be the basis of new solid plant-based products whose sensory properties can be modulated by varying the concentration of natural ingredients.

Use of psyllium husk powder: Effects on emulsion stabilised by fish muscle proteins and gel characteristics of fish tofu

SummaryIn‐vitro studies on emulsifying properties of psyllium (Plantago ovata) husk (PSY) powder at various concentrations using natural actomyosin (NAM) extracted from threadfin bream (Nemipterus sp.) mince were investigated. Emulsion activity and stability indexes were increased with the addition of PSY at 1.25 g/100 mL (PSY‐E1) and 2.50 g/100 mL(PSY‐E2) (P &lt; 0.05). Overall, PSY‐E1 and PSY‐E2 emulsions had the highest turbidity and lower particle size. Moreover, gel properties and consumer acceptability of fish tofu added without and with PSY powder at varying concentrations were also elucidated. No difference in breaking force (Br‐F) was observed between all samples, except tofu added with PSY at 5.00 g/100 g, which had the highest Br‐F (P &lt; 0.05). However, the lowest deformation (De‐F) was also attained for PSY‐T3 (P &lt; 0.05). Colour of fish tofu decreased with augmenting levels of PSY. Microstructure of fish tofu revealed the formation of an unordered network with thicker strands as PSY levels upsurged. Fish tofu containing PSY at 1.25–2.5 g/100 g showed a similar overall likeness score to that of control fish tofu. Therefore, PSY at the optimum level enhanced the emulsion stability. Moreover, PSY at 1.25–2.5 g/100 g could improve gel properties without a negative impact on the consumer acceptability of fish tofu.

Synthesis and characterization of biosilica gel produced from teff (Eragrostis tef) straw using the sol-gel technique

In this work, biosilica gel was synthesized using the sol-gel method from teff straw. Silica gel was synthesized from teff straw ash prepared at calcination temperatures of 500 to 900 °C using a 2.5 N NaOH solution. The silica gel yield increases with calcination temperature from 500 to 800 °C and decreases at 900 °C. The maximum yield (94.2 %) was attained at 800 °C. Further, the physiochemical and morphological characteristics of silica gel were characterized using FTIR, XRD, SEM, EDX, and BET. The silica gel functional group-specific characteristic peaks were only seen in FT-IR spectra, and amorphous silica gel was confirmed by XRD. By using SEM, the surface structure was identified. The performance of silica gel with a purity of 99.39 % and the highest surface area of 807.163 m2/g, a pore volume of 0.34 cm3/g, and a pore diameter of 1.70 nm was observed at 700 °C.

FORMULASI DAN UJI MUTU FISIK SEDIAAN GEL EKSTRAK BUNGA TELANG (Clitoria ternatea L.) SEBAGAI ANTISEPTIK TANGAN

Hands are one of the media for microbial growth, dirty hands become a breeding ground for microbes such as Staphylococcus aureus and Escherichia coli or other bacteria. How to maintain hand hygiene is to wash your hands with soap or use an antiseptic (hand sanitizer). Antiseptic preparations are substances that have been widely used to inhibit the growth and kill microorganisms that exist around the body surface, for example on the palms of the hands that often come into contact with the surface of an object. One of the natural ingredients that has the potential to be developed as a hand antiseptic is telang flower (Clitoria ternatea). This research will formulate antiseptic gel preparations from telang flower extract, and how to test the physical quality of antiseptic gel preparations from telang flower extract. The method used for the extraction process here uses the maceration method, to maintain the antimicrobial compounds contained in the telang flower, followed by testing the physical characteristics and quality of the telang flower gel preparation, including, Organoleptic Test, pH test, Viscosity test, Homogeneity test, Spreadability test, adhesion test. After testing the characteristics and physical quality of the gel preparations of telang flower extract, the results were quite optimal, namely with a pH value in the range of 4.26-4.41 according to skin pH, and for viscosity at a value of 64% - 33%, in accordance with the characteristics of a good gel. Telang flower extract can be made and formulated as an antiseptic hand gel preparation. Variations in the concentration of the extract used greatly affect the characteristics of the gel preparation, starting from pH, viscosity, adhesion, and dispersion. The higher the concentration of the extract used, the lower the viscosity value, and the lower the pH value. The pH value and viscosity value for all formulas were in accordance with the skin parameter criteria, namely 3.5-6.5. Based on research conducted, Formula 3 using a concentration of 0.5 has. the most optimal gel preparation

Yam Bean (Pachyrhizus erosus L. Urban) Powder Improves Grass Carp Myofibrillar Protein Gel by Forming Disulfide Bonds, Hydrogen Bonds, and Proper Microstructure.

This study aimed to analyze the impact of different additions (0-1.25%) of yam bean powder (YBP) on myofibrillar protein (MP) gel characteristics such as the structure, water-holding capacity (WHC), chemical interaction strength of grass carp MP, and texture. The results showed that the YBP exhibited a strong water absorption capacity and filled in the protein heat-induced polymerization gel network well, which enabled the gel network to capture and retain water effectively, resulting in MP gels containing YBP with excellent WHC and gel strength (0.75%). In addition, YBP induced the formation of hydrogen and disulfide bonds in proteins and inhibited the conversion of α-helices to β-sheets and β-turn structures, facilitating the formation of high-strength gel networks (p < 0.05). In conclusion, YBP can significantly improve the thermally induced gelling properties of grass carp MP. In particular, the addition of 0.75% YBP had the best effect in terms of filling the gel network of grass carp MP, resulting in the formation of a continuous and dense protein network, leading to the composite gel with the best WHC and texture.

Gel Properties and Structural Characteristics of Composite Gels of Soy Protein Isolate and Silver Carp Protein.

Problems with silver carp protein (SCP) include a strong fishy odor, low gel strength of SCP surimi, and susceptibility to gel degradation. The objective of this study was to improve the gel quality of SCP. The effects of the addition of native soy protein isolate (SPI) and SPI subjected to papain-restricted hydrolysis on the gel characteristics and structural features of SCP were studied. The β-sheet structures in SPI increased after papain treatment. SPI treated with papain was crosslinked with SCP using glutamine transaminase (TG) to form a composite gel. Compared with the control, the addition of modified SPI increased the hardness, springiness, chewiness, cohesiveness, and water-holding capacity (WHC) of the protein gel (p < 0.05). In particular, the effects were most significant when the degree of SPI hydrolysis (DH) was 0.5% (i.e., gel sample M-2). The molecular force results demonstrated that hydrogen bonding, disulfide bonding, and hydrophobic association are important molecular forces in gel formation. The addition of the modified SPI increases the number of hydrogen bonds and the disulfide bonds. Scanning electron microscopy (SEM) analysis showed that the papain modifications allowed the formation of a composite gel with a complex, continuous, and uniform gel structure. However, the control of the DH is important as additional enzymatic hydrolysis of SPI decreased TG crosslinking. Overall, modified SPI has the potential to improve SCP gel texture and WHC.

Effect of micro- and nano-sized emulsion fillers combined with trans-cinnamaldehyde on the physicochemical and rheological characteristics of myofibrillar protein gels

In this study, we investigated the influence of trans-cinnamaldehyde (CIN) and emulsion size on the physicochemical properties and functionality of emulsion gels. Myofibrillar protein or lecithin emulsions were fabricated with different ratios of canola oil and CIN and different emulsion droplet sizes. The emulsion gels showed a significant dependence on CIN concentration in terms of gel strength and rheological properties because of the improved interaction between proteins and aldehydes through the Schiff base reaction. In addition, the physical properties of the micro-sized emulsion gels were better than those of the nano-sized gels. There was no significant difference in the water-holding capacity. According to the scanning electron and confocal microscopy images, the CIN emulsion gels formed a denser microstructure and had a higher homogeneity with higher CIN concentrations. This suggested that CIN promoted protein cross-linking because the monophenol molecule had fewer structural obstacles. The structural properties were analyzed using Fourier-transform infrared spectroscopy. It was also confirmed that lipid oxidation was inhibited by CIN. The information obtained in this study could be used to develop protein-based products with novel functional properties for use in meat products and in other applications.

Effect of microbial transglutaminase on functional, rheological, and structural properties of lentil protein-casein binary gels

In recent years, various strategies have been introduced to partially substitute animal proteins with plant proteins. This study applied microbial transglutaminase (MTGase) to crosslink lentil protein isolate (LPI) and casein. The gel mixtures prepared using different LPI-casein ratios (4:0, 3:1, 2:2, 1:3, 0:4), and the structural, gelation characteristics of these hetero-mixtures were investigated. SDS-PAGE showed the bands of vicilins (∼50 kDa), and 11S acidic subunit (∼40 kDa) almost disappeared and partly 11S basic subunit (20 kDa) involved in the polymerization, whereas almost all the bonds of casein were involved in the MTGase-induced gelation process. With the increasing concentration of casein, LPI-casein binary gels presented enhanced mechanical textural properties (increased from 284.83 to 1128.33g of hardness), rheological properties (increased from 105.8 to 4405 Pa of storage modulus), water holding capacity (increased from 63.86 to 98.82%) and more homogeneous and compact microstructural properties (CLSM, SEM) as a result of homologous and heterologous crosslinking mediated by MTGase. Interestingly, gels prepared by partial casein replacement (by 25% LPI) had similar textural, water holding capacity, and microstructural properties to those prepared by casein-alone gels, demonstrating the possibility of successfully replacing casein with 25% LPI in MTGase induced system. This study presents a new interaction strategy mediated by MTGase for LPI and casein binary system to greatly enhance their gelation performance, as well as the potential of LPI in substitute dairy to formulate diversified food products.

Multiscale mechanical characterization and computational modeling of fibrin gels.

Fibrin is a naturally occurring protein network that forms a temporary structure to enable remodeling during wound healing. It is also a common tissue engineering scaffold because the structural properties can be controlled. However, to fully characterize the wound healing process and improve the design of regenerative scaffolds, understanding fibrin mechanics at multiple scales is necessary. Here, we present a strategy to quantify both the macroscale (1-10mm) stress-strain response and the deformation of the mesoscale (10-1000µm) network structure during unidirectional tensile tests. The experimental data were then used to inform a computational model to accurately capture the mechanical response of fibrin gels. Simultaneous mechanical testing and confocal microscopy imaging of fluorophore-conjugated fibrin gels revealed up to an 88% decrease in volume coupled with increase in volume fraction in deformed gels, and non-affine fiber alignment in the direction of deformation. Combination of the computational model with finite element analysis enabled us to predict the strain fields that were observed experimentally within heterogenous fibrin gels with spatial variations in material properties. These strategies can be expanded to characterize and predict the macroscale mechanics and mesoscale network organization of other heterogeneous biological tissues and matrices. STATEMENT OF SIGNIFICANCE: Fibrin is a naturally-occurring scaffold that supports cellular growth and assembly of de novo tissue and has tunable material properties. Characterization of meso- and macro-scale mechanics of fibrin gel networks can advance understanding of the wound healing process and impact future tissue engineering approaches. Using structural and mechanical characteristics of fibrin gels, a theoretical and computational model that can predict multiscale fibrin network mechanics was developed. These data and model can be used to design gels with tunable properties.

Yttrium Oxide Nanoparticle-Loaded, Self-Assembled Peptide Gel with Antibacterial, Anti-Inflammatory, and Proangiogenic Properties for Wound Healing.

Chronic wounds are a major healthcare challenge owing to their complex healing mechanism and number of impediments to the healing process, like infections, unregulated inflammation, impaired cellular functions, poor angiogenesis, and enhanced protease activity. Current topical care strategies, such as surgical debridement, absorption of exudates, drug-loaded hydrogels for infection and inflammation management, and exogenous supply of growth factors for angiogenesis and cell proliferation, slow the progression of wounds and reduce patient suffering but suffer from low overall cure rates. Therefore, we have developed a proteolytically stable, multifunctional nanoparticle loaded-peptide gel with inherent anti-inflammatory, antibacterial, and pro-angiogenic properties to provide a favorable wound healing milieu by restoring impaired cellular functions. We have fabricated a self-assembled, lauric acid-peptide conjugate gel, LA-LLys-DPhe-LLys-NH2, loaded with yttrium oxide (Y2O3) nanoparticles (NLG). Gel formed a nanofibrous structure, and nanoparticles were passively entrapped within the network. The surface morphology, stability, viscoelastic, and self-healing characteristics of gels were characterized. It showed a high stability against degradation by proteolytic enzymes and highly potent antibacterial activities against E. coli and S. aureus due to the presence of positively charged side chains of lysine in the peptide chain. It also exhibited an excellent antioxidant activity as well as ability to stimulate cell proliferation in murine fibroblast (L929) cells and human umbilical vein endothelial cells (HUVECs). The incorporation of nanoparticles promoted angiogenesis by upregulating pro-angiogenic genes, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF2), and epidermal growth factor (EGFR), and the gel caused complete wound closure in cells. In summary, the Y2O3 nanoparticle-loaded lauric acid-peptide conjugate gel is able to elicit the desired tissue regeneration responses and, therefore, has a strong potential as a matrix for the treatment of chronic wounds.

Mussel‐mimetic chitosan based injectable hydrogel with fast-crosslinking and water-resistance as tissue adhesive

It is very crucial to develop ideal tissue adhesive materials with high toughness, super tissue adhesion, biodegradability and biocompatibility for the treatment of accidental trauma and surgery. Inspired by mussels, a novel injectable bioadhesive chitosan-based hydrogel was developed by dual-ionic crosslinking in this paper, which was composed of catechol-modified chitosan (Cat-CS), thermosensitive polymer (PNAM) and NaHCO3. The gelation time of Cat–CS–PNAM/NaHCO3 hydrogel is 50 s at 37 °C, showing good sol-gel transition under different temperatures. The prepared hydrogels have the ability to adhere to a variety of materials surface, wherein the adhesion strength to metal surface is 126.20 ± 15.17 kPa. They also possess compact microstructure and excellent dry/wet adhesion to tissues due to the interaction between catechol/amino groups and tissues, combined with physical crosslinking. In addition, the hydrogels can be completely degraded after 14 days in vitro and show good cytocompatibility. This newly designed mussel-inspired chitosan hydrogels have the characteristics of injectability, fast gelation, bioadhesion and biocompatibility, with great potential for application in biomedical fields.

Improved oil recovery in sandstone reservoirs with deep profile control technology: A comparative study between modified starch gel and polymer gel

Deep profile control technology was implemented to alleviate the issue of oil recovery in sandstone reservoirs caused by varying permeability. Rheological tests, injection and plugging capacity experiments, core flooding experiments combined with Computed Tomography (CT) analysis were performed to study the mechanisms of profile control, oil displacement, rheology, and plugging properties of modified starch gel and polymer gel. Moreover, a comparison was made regarding the oil recovery, sweep efficiency, and displacement efficiency for both the starch gel and polymer gel. The results show that the ease of injection and plugging properties of the modified starch gel are superior to those of the viscoelastic polymer gel. The visual and quantitative distribution profiles and migration characteristics of water, oil, and gels are characterized. During the gel flooding stage, the modified starch gel maintained a rigid shape compared to the lax behavior observed with polymer gel. During the subsequent water flooding stage, the modified starch gel became immobile. It plugged the high permeability layer of the core plug, increasing the sweep efficiency of the low permeability layer by 60.00%. The sweep efficiency of the low permeability layer increased by 37.26% as the polymer gel continued to flow through the core plug. In addition, the high permeability layer is easily swept clean, so enhancing the displacement efficiency is the key to maximizing recovery. The displacement and relatively easy sweep efficiencies must be improved simultaneously to maximize the recovery in the low permeability layer. The study's findings shed light on the significance of modified starch gel in enhancing oil recovery in sandstone reservoirs with varying permeability.

Multi-dimensional analysis of heat-induced soybean protein hydrolysate gels subjected to ultrasound-assisted pH pretreatment

This study aimed to evaluate the gelation characteristics of soybean protein hydrolysate (SPH) extracted by enzyme-assisted aqueous extraction. Specifically, the changes in gelation behaviors for heat-induced (95 °C, 20 min) SPH dispersions treated with pH (pH 3, 5, 9; pH 7 as control) and ultrasound (U; 240 W, 30 min) were investigated. The results showed that typical gel behavior with high elastic nature in the viscoelasticity and network structures were observed during the heating process, where the disulfide bond played a dominant role in the gel network formation of all the samples. Notably, the heat-induced aggregation in the SPH gels was mainly formed by the association of the basic B polypeptide in 11S and β subunit in 7S. The most superior SPH gel was formed at pH 7 when assisted by ultrasonication during the heating process. This as-synthesized gel showed a uniform filamentous structure and exhibited the more excellent textural, rheological and thermal properties than those of the samples formed under acidic and alkaline conditions. These results are of great value in revealing the gelation mechanism of SPH.

Effect of high‐content ultrasonically emulsified lard on the physicochemical properties of surimi gels from silver carp enhanced by microbial transglutaminase

SummaryThe objective of this study was to investigate the effect of ultrasonically emulsified lard combined with microbial transglutaminase (MTGase) on the physicochemical characteristics of surimi gel from silver carp. Surimi gel with ultrasonically emulsified lard had higher whiteness, gel strength and water‐holding capacity. Storage modulus and loss modulus decreased with the addition of lard or ultrasonically emulsified lard to the surimi. However, the gel strength and WHC presented a decreasing tendency in surimi gels with more addition of ultrasonically emulsified lard, because the gel network could not overcome the damaging effect of higher ultrasonically emulsified lard (&gt;6 g 100 g−1). MTGase increased the cross‐linking degree of gels (P &lt; 0.05) regardless of the presence or absence of lard or ultrasonically emulsified lard. MTGase provided a denser and stronger gel network to ensure the stability of oil droplets. In general, the combination of ultrasonically emulsified lard and MTGase could effectively improve the color, textural and rheological characteristics of surimi‐based products.

Acid-induced Poria cocos alkali-soluble polysaccharide hydrogel: Gelation behaviour, characteristics, and potential application in drug delivery

Poria cocos alkali-soluble polysaccharide (PCAP), a water-insoluble β-glucan, is the main component of the total dried sclerotia of Poria cocos. However, its gelation behaviour and properties have yet to be comprehensively studied. In this study, an acid-induced physical hydrogel based on natural PCAP is fabricated. The acid-induced gelation in PCAP is explored with respect to the pH and polysaccharide concentration. PCAP hydrogels are formed in the pH range of 0.3–10.5, and the lowest gelation concentration is 0.4 wt%. Furthermore, dynamic rheological, fluorescence, and cyclic voltammetry measurements are performed to elucidate the gelation mechanism. The results reveal that hydrogen bonds and hydrophobic interactions play a dominant role in gel formation. Subsequently, the properties of the PCAP hydrogels are investigated using rheological measurements, scanning electron microscopy, gravimetric analysis, free radical scavenging, MTT assays, and enzyme-linked immunosorbent assays. The PCAP hydrogels exhibit a porous network structure and cytocompatibility, in addition to good viscoelastic, thixotropic, water-holding, swelling, antioxidant, and anti-inflammatory activities. Furthermore, using rhein as a model drug for encapsulation, it is demonstrated that its cumulative release behaviour from the PCAP hydrogel is pH dependent. These results indicate the potential of PCAP hydrogels for application in biological medicine and drug delivery.

Optimization of The Combination of CMC-Na and Glycerin in Tobacco (Nicotiana tabacum L.) Hand Sanitizer Gel Using The Simplex Lattice Design

Tobacco leaves have active compounds such as phenols and alkaloids that can be used as antibacterial and antiseptic because they can damage the cell components of microorganisms. Tobacco leaf extract in hand sanitizer gel has been shown to have antibacterial activity against Staphylococcus aureus and Eschericia coli bacteria at a minimum concentration of 0.25%. Hand sanitizer is an antiseptic product that is used to clean hands and is preferred because it is practical, has a cooling and dries quickly when compared to hand soap. To make hand sanitizer products that are safe for the skin, various chemical compounds are used as building blocks, including CMC-Na and glycerin. CMC-Na acts as a gelling agent and glycerin has a role as a vehicle. This study aims to obtain the optimum formula for hand sanitizer gel preparations with variations in the concentration ratio of CMC-Na and glycerin using Simplex Lattice Design (SLD) and to determine the effect of variations in the concentration ratio of CMC-Na and glycerin on physical, chemical, and microbiological characteristics of the results of the optimum formula for hand sanitizer gel preparations. The research method used in this study is a type of laboratory experiment using Completely Randomized Design (CRD). The data obtained from the research results were processed using Analysis of Variance (ANOVA) with a 95% confidence level and continued with Duncan's Multiple Range Test at a significance level of 5%. The results showed that there were 3 optimum formulas for hand sanitizer gel of tobacco leaf extract based on the desirability value, 0.912 (Formula 1), 0.457 (Formula 4) and 0.653 (Formula 5). The variation of the concentration ratio of CMC-Na and glycerin in the optimum formula showed that CMC-Na had the most dominant influence on physical (homogeneity), chemical (total flavonoid) and microbiological (antibacterial and antiseptic) characteristics. Meanwhile, glycerin has the most dominant influence on product viscosity stability. The three optimum formulas have homogeneous gel characteristics.

Gelation properties of silver carp (Hypophthalmichthys molitrix) surimi as affected by phenolic compounds in lotus root knot extract

ABSTRACT The objective of this study was to investigate the effects of aqueous extract of lotus root knot (AELRK) on the gel characteristics of silver carp surimi. Gel strength, storage modulus, and disulfide bond of surimi gels were significantly increased with the addition of the AELRK (p < 0.05), especially at 10% AELRK (p < 0.05), where gel strength and disulfide bond were enhanced by 14.7% and 41.6%, respectively, but decreased in expressible moisture content, ionic bond, hydrogen bond and hydrophobic interaction. Adding 10% AELRK could enhance cross-linking degree surimi gels with the denser and smoother microstructure. There was the reduction in myosin heavy chain but not significant change in actin. More addition of the AELRK significantly decreased in L* and whiteness of surimi gels (p < 0.05) but increased in a * . Therefore, there would be a potential to utilize the phenolic compounds from lotus root to improve the quality of silver carp surimi.