Gel Melting Research Articles

Frabrication of carboxymethylchitin nanofibers and fish gelatin hybrid gels with robust gel performance

Compared to animal gelatin, the application of fish gelatin (FG) in the food industry is limited due to its lower gel hardness, gelation temperature, and melting temperature. To address these issues, we developed hybrid gels using carboxymethyl chitin nanofibers (CMC-NFs) with FG to enhance its gel properties. The chitin was carboxymethylated by monochloroacetic acid, increasing the negative potential from −6 mV to −35 mV. This modified chitin was then defibrillated into CMC-NFs through high-pressure homogenization to improve its water dispersibility. The addition of 0.1% CMC-NFs significantly increased the hardness of FG gels from 533 g to 989 g, which was notably higher than the ∼600 g hardness of porcine gelatin. Additionally, the gelation and melting temperatures of FG reached 17 °C and 32 °C, respectively, which are very close to the 20 °C and 35 °C of porcine gelatin. Mechanistic studies revealed that FG and CMC-NFs (0.1%) molecules formed a synergistic gel network, facilitated by hydrogen bonding and hydrophobic interactions. This interaction significantly increased the α-helix content in the secondary structure of the FG protein from 15.26% to 21.18%, thereby enhancing the FG-dominated three-dimensional network structure with CMC-NF molecules. Increasing the concentration of CMC-NFs further elevated the gel's melting temperature while reducing its hardness due to phase separation. This study not only presents a viable method for enhancing the gelling properties of modified FG but also offers a feasible solution for expanding FG's applications in the food industry.

Effects of glycation modifications of different glycosylating agents on the molecular structure and gel properties of sheep's hoof gelatin

In this study, we utilized sheep's hoof gelatin as a raw material to modify gelatin by non-enzymatic glycation reactions using five different monosaccharides (D-glucose, D-sorbose, D-fructose, D-ribose, and D-erythrose) and five different polysaccharides (pectin, inulin, carrageenan, xanthan gum, and konjac glucomannan) and comparatively analyzed the properties (rheological properties, textural properties, and thermal stability) of differently glycosylated sheep's hoof gelatin to determine the mechanism of different glycosylating agents on the molecular properties and gel performance of sheep's hoof gelatin. The results showed that the reactivity (DG value) and phase transition temperature (Td value) of gelatin modified with monosaccharide glycosylates were notably higher (p < 0.05) compared to those modified with polysaccharides, resulting in a micro-network structure with finer pore size. Conversely, polysaccharide glycosylation significantly enhanced the mechanical properties and rheological characteristics of gelatin (p < 0.05). The formation of a mosaic network structure in the polysaccharide-glycosylated gelatin group played a pivotal role in enhancing gel properties. Notably, the gel strength (584.62 ± 6.34 g), viscosity (η-value), and gel melting temperature (37.85 ± 0.20 °C) of the polysaccharide S-PEC were significantly higher than the other treatment groups (p < 0.05). This research not only provides a new perspective for modifying gelatin derived from sheep's hooves but also offers an important theoretical basis for the exploration and application of gelatin materials in the food industry.

Elucidating the rheological and thermal properties of mixed fish and pork skin gelatin gels: Effects of cooling conditions and incubation times

Gelatin is an important hydrocolloid in food and biotechnological applications. There are two basic sources of gelatins; mammalian and fish-derived gelatins, but fish gelatins are less appreciated due to their weak gel properties. Hence, to reinforce the gel properties of fish gelatin, mixtures of gelatins are used. In this study, the mixtures of cold-water ocean fish scale (OFS) and pork skin (PS) gelatin were studied via rheological measurements, micro differential scanning calorimetry (DSC), and particle tracking at different cooling conditions and incubation times to understand the gelation mechanism and the network structure of the gels. The rheological and micro-DSC measurements provide a detailed understanding of the gelation mechanism of gelatin gels under different cooling conditions while particle tracking revealed the local physical properties of the gels. A single or two-step melting was demonstrated in the mixed gelatin gels depending on the cooling conditions suggesting that the aggregation of PS in the mixtures influences the physical and thermal properties of the gels. Under rapid cooling, co-aggregation of OFS and PS chains is considered to cause a single-step melting of the mixed gels. Under gradual cooling, conversely, the PS may form aggregates independently before the OFS. This is evidenced by a two-step decrease in moduli and two clear endothermic peaks in the micro-DSC measurement. Particle tracking further reveals information on the local physical properties of pure and mixed gelatin gels on reheating, indicating that the local structures of mixed gels resemble those of pure PS gels. This suggests that mixed OFS and PS gels may form a cooperative aggregation, thereby improving the physical and thermal properties of the mixed gelatin gels.

Multiplex Asymmetric PCR by Combining the Amplification Refractory Mutation System with the Homo-Tag-Assisted Nondimer System.

Asymmetric PCR is widely used to produce single-stranded amplicons (ss-amplicons) for various downstream applications. However, conventional asymmetric PCR schemes are susceptible to events that affect primer availability, which can be exacerbated by multiplex amplification. In this study, a new multiplex asymmetric PCR approach that combines the amplification refractory mutation system (ARMS) with the homo-Tag-assisted nondimer system (HANDS) is described. ARMS-HANDS (A-H) PCR utilizes equimolar-tailed forward and reverse primers and an excess Tag primer. The tailed primer pairs initiate exponential symmetric amplification, whereas the Tag primer drives linear asymmetric amplification along fully matched strands but not one-nucleotide mismatched strands, thereby generating excess ss-amplicons. The production of ss-amplicons is validated using agarose gel electrophoresis, sequencing, and melting curve analysis. Primer dimer alleviation is confirmed by both the reduced Loss function value and a 20-fold higher sensitivity in an 11-plex A-H PCR assay than in an 11-plex conventional asymmetric PCR assay. Moreover, A-H PCR demonstrates unbiased amplification by its allele quantitative ability in correct identification of all 31 trisomy 21 samples among 342 clinical samples. A-H PCR is a new generation of multiplex asymmetric amplification approach with various applications, especially when sensitive and quantitative detection is required.

Ecofriendly and scalable production of bioglass using an organic calcium source enhanced bioactivity for tissue repair

The eco-friendly and scalable production of bioglass remains a challenging but attractive strategy for advancing its widespread biomedical applications. Although the sol–gel method has been considered a valuable approach for bioglass production, the application of calcium nitrate as a calcium source markedly limits its industrialization owing to environmental pollution, high administration costs, and numerous calcium-rich regions in the as-prepared bioglass. Therefore, organic Ca has been proposed as an alternative to inorganic Ca. In the current study, bioglass was successfully prepared using a novel calcium source (calcium glycerol) and was named regeneration silicon (RegeSi). The biocompatibity of bioglass was examined by performing the methyl thiazolyl tetrazolium (MTT) assay using L929 fibroblasts. The biological and tissue repair properties of RegeSi were better than those of bioglass prepared with calcium nitrate using the sol–gel or traditional melting methods. The applicability of RegeSi was validated using suitable wound healing and dental restoration models. Notably, RegeSi ensured closure of a deep wound (1.6 cm diameter, 2 mm depth) within 11 d. Moreover, RegeSi facilitated tooth repair with a blocking rate of 97.1%. More importantly, large-scale production of RegeSi was achieved at low cost, high bioactivity, and using environmental technology, reaching a capacity of 100 kg/batch.

Comparative gelation characteristics of carrageenan via rheological and optical techniques: Glazing gels with different sweeteners

Glazing gels used as decorative gels are most often applied by hot spraying of solutions based on fast-setting hydrocolloids. The formation of a non-sticky gel at room conditions is crucial for their use. Gel formation and gel melting of carrageenan-based glazing gels (CGGs) with various sweeteners (trehalose, erythritol with stevia, maltitol, oligofructose, and nutriose with sucralose and acesulfame) were monitored during cooling-heating cycles using both the oscillatory rheology and the multispeckle diffusing wave spectroscopy (MS-DWS). In addition, rheological properties (shear viscosity of sols, the viscoelastic properties of gels, gel breaking strain) and texture properties (gel strength, elasticity and rupture force) were evaluated. The 12% addition of sweeteners resulted in a significant increase in gelling and melting temperatures by 2–6 °C compared to the sugar-free control sample (42 °C and 57 °C, resp.). MS-DWS, as opposed to oscillatory rheology, allowed determining of the characteristic temperatures at the beginning, middle and end of the phase transitions. The rheology gelling temperatures correlated best with the end of the gelation process, while the melting temperatures corresponded to the middle point temperature of the MS-DWS. Mechanical properties showed CGGs create a continuous gel structure characterized by a viscoelastic solid with comparable hardness and strength at small deformation, and greater elasticity compared to the sugar-free control sample. CGGs containing small molecule sweeteners formed stronger gels against rupture at large deformation than those ones with macromolecular structure. Sols of all CGGs were clear dispersions at 70 °C with Newtonian fluids characteristics and low viscosity (in the range of 9.3–10.9 mPas). These findings prove CGGs with various sugar-replaced sweeteners could be applied by hot spraying method and indicate how MS-DWS can be used to monitor gelation processes.

High-moisture extrusion of curdlan: Texture and structure

High-moisture extrusion is a promising thermomechanical technology extensively employed in manufacturing fibrous meat analogues from plant-based proteins, garnering considerable research attention. However, polysaccharide-based extrusion has been rarely explored. The present study investigates the effects of varying extruder barrel temperatures (130 °C–200 °C) on the texture and structure of curdlan extrudates, and highlights the formation mechanism. Results showed that the single chain of curdlan aggregates to form triple-helix chains upon extrusion, consequently enhancing the crystallinity, particularly at 170 °C. The hardness, chewiness, and mechanical properties improved with increasing barrel temperature. Moreover, barrel temperatures affected the macrostructure, the extrudates maintained intact morphologies except at 160 °C due to the melting of curdlan gel as confirmed by the differential scanning calorimetry thermogram. Microstructural analysis revealed that curdlan extrudates transited through three phases: original gel (130 °C, 140 °C, and 150 °C), transition state (160 °C), and regenerated gel (170 °C, 180 °C, 190 °C, and 200 °C). The steady state of regenerated gel (170 °C) exhibited higher crystallinity and smaller fractal dimension, resulting in a more compact and crosslinked gel network. This study elucidates the structure transition of curdlan gel at extremely high temperatures, offering valuable technical insights for developing theories and methods with respect to polysaccharide-based extrusion that may find applications in food-related fields.

Strong gelation capacity of a pectin-like polysaccharide in the presence of K+ ion

In the present study, a pectin-like apple polysaccharide (AP) obtained by metal precipitation technique was demonstrated to show strong gelling capacity in the presence of K+ ion upon cooling. Increasing amount of K+ addition monotonically promoted the gelation of AP, as characterized by the increased gelation temperature (Tgel), gel melting temperature (Tmelt) and the gel strength. Compared with K+ ion, Na+ was unable to induce AP gelation even at high ionic concentrations, but other monovalent cations (Rb+, Cs+) can induce the gelation as in the case of K+ addition. At room temperature, the minimum cationic concentration as required to induce AP gelation followed the order of K+ ≈ Cr+ (8 mM) > Rb+ (3.5 mM), indicating that cationic radius (Na+ < K+ < Rb+ < Cs+) played a dominant role in inducing AP gelation, but other factors may also be involved. Finally, the gelation behavior of AP in the presence of K+ was explained as the suppressed intermolecular electrostatic repulsion between AP chains due to the strong electrostatic shielding effect of K+, which led to the formation of a gel network mediated by intermolecular hydrogen bonding. This reported gelation property may allow AP to find application as a new gelling polysaccharide.

Improving gelling properties of fish gelatin by γ‐polyglutamic acid with four different molecular weights

SummaryThis work investigated gelling properties and structural characteristics of fish gelatin (FG) modified by four different molecular weights of γ‐polyglutamic acid (γ‐PGA) with 700, 1000, 2000 and 3000 kDa, respectively. Gelation‐melting transition temperature and gel strength increased with the increase of molecular weight in γ‐PGA. Especially, γ‐PGA in 3000 kDa made gel strength, gelation and melting temperatures reaching to 628.08 g (P &lt; 0.05), 22.30 °C and 30.17 °C (P &lt; 0.05), respectively. Non‐covalent interactions existed in FG and γ‐PGA. Such as, new hydrogen bonds were generated between them. Moreover, γ‐PGA with increased molecular weight enhanced three‐stranded helical structure and microscopic meshwork of FG. Finally, a schematic model was described to illustrate the interaction between FG and γ‐PGA in different molecular weights. On the whole, γ‐PGA with high molecular weight significantly improved gelling properties of FG, and could be a potential modifier of FG in the future.

Molecular characterisation, gelation kinetics and rheological enhancement of ultrasonically extracted triggerfish skin gelatine

Improper fish skin disposal raises environmental and health concerns, highlighting the need for sustainable waste management. Turning discarded fish skins into marketable products like gelatine benefits both the economy and ecology. This study aims to investigate the feasibility of employing ultrasonic technique for the recovery of gelatine from the collagen-rich titan triggerfish skin following a preliminary pretreatment. The applied ultrasonic parameters included 100 W power, 40 kHz frequency, and a temperature held at 50 °C over a 3 h duration, resulting in a maximum gelatine yield of 20.5 ± 0.3 % (w/w) based on wet weight measurements. The biochemical and functional attributes of the extracted triggerfish gelatine (TFG) were compared to those of commercial bovine gelatine (CBG). TFG exhibited a substantial protein content (92.2 ± 0.2 %), along with low levels of moisture (7.4 ± 0.1 %), fat (0.2 ± 0.1 %), and ash (0.2 ± 0.04 %). SDS-PAGE showed that the primary elements of TFG were β- and α-chains (MW ∼ 150 to 220 kDa). While both gelatine types displayed predominant FTIR bands in the amide area (amide-I, amide-II and amide-ІІІ), TFG spectra, however, suggested that the ultrasonic treatment had no discernible effect on its triple helical structure. Significant variations in the gross amino acid profiles were found in both TFG and CBG. Nevertheless, compared to CBG, TFG had lower levels of proline and hydroxyproline residues. Additionally, TFG exhibited relatively lower gel strength; however, the optimal inclusion of microbial transglutaminase (MTGase) increased its gel strength (394±4 g) and melting temperature (Tmp = 31.9 °C), while reducing gelation time (<50 min at 20 °C). Functionally, TFG demonstrated higher foaming but marginally lower emulsifying properties than CBG. The finding underscores the potential of ultrasonication to mitigate fish skin waste emissions and efficiently retrieve high-quality gelatine within a shorter time frame.

Development of Gelled-Oil Nanoparticles for the Encapsulation and Release of Berberine.

In this study, a new drug carrier based on gelled-oil nanoparticles (GNPs) was designed and synthesized for the encapsulation and release of the model hydrophobic drug, berberine chloride (BCl). Two compositions with different oil phases were examined, sesame oil (SO) and cinnamaldehyde (Cin), which were emulsified with water, stabilized with Tween 80 (Tw80), and gelled using an N-alkylated primary oxalamide low-molecular-weight gelator (LMWG) to give stable dispersions of GNPs between 100 and 200 nm in size. The GNP formulation with Cin was significantly favored over SO due to (1) lower gel melting temperatures, (2) higher gel mechanical strength, and (3) significantly higher solubility, encapsulation efficiency, and loading of BCl. Also, the solubility and loading of BCl in Cin were significantly increased (at least 7-fold) with the addition of cinnamic acid. In vitro release studies showed that the release of BCl from the GNPs was independent of gelator concentration and lower than that for BCl solution and the corresponding nanoemulsion (no LWMG). Also, cell internalization studies suggested that the N-alkylated primary oxalamide LMWG did not interfere with the internalization efficiency of BCl into mouse mast cells. Altogether, this work demonstrates the potential use of these new GNP formulations for biomedical studies involving the encapsulation of drugs and nutraceuticals and their controlled release.

The Invasive Seaweed Agarophyton vermiculophyllum from Oualidia Lagoon (Northwestern Moroccan Atlantic Coast) as a Source of Agar: Yield, Chemical Characteristics, and Rheological Properties

Agar is a hydrophilic biopolymer extracted from red seaweed. This phycocolloid consists of two components: agarose and agaropectin. In the present work, agar extracted from the invasive red seaweed Agarophyton vermiculophyllum was characterized using physical, chemical, and spectroscopic analyses to investigate the effect of alkaline pretreatment on agar properties. Two extraction conditions, native and alkali-pretreated agars, were comparatively studied. The native yield (28.4 ± 0.9%) was higher than that of the alkaline-pretreated agar (20.4 ± 0.8%). The alkali-pretreated agar showed higher gel strength (763.8 ± 57.0g cm−2), gelling (36.5 ± 0.9 °C), and melting (83.2 ± 0.6 °C) temperatures and increased 3,6-anhydrogalactose (26.2 ± 1.9%) and decreased sulfate contents (6.2 ± 0.8%) compared with native agar (gel strength: 204.8 ± 17.10g cm−2, gelling temperature: 29.5 ± 0.9 °C, melting temperature: 73.4 ± 0.7 °C, 3,6-AG content: 13.8 ± 0.7%, sulfate content: 10.5 ± 0.5%). The alkaline pretreatment improved the agar’s gelling properties and significantly influenced its chemical properties. In view of the obtained results, A. vermiculophyllum might potentially be thought of as a viable source for the agar industry in Morocco, serving as a local source of agar.

Agarose Fluid Gels Formed by Shear Processing During Gelation for Suspended 3D Bioprinting.

The use of granular matrices to support parts during the bioprinting process was first reported by Bhattacharjee et al. in 2015, and since then, several approaches have been developed for the preparation and use of supporting gel beds in 3D bioprinting. This paper describes a process to manufacture microgel suspensions using agarose (known as fluid gels), wherein particle formation is governed by the application of shear during gelation. Such processing produces carefully defined microstructures, with subsequent material properties that impart distinct advantages as embedding print media, both chemically and mechanically. These include behaving as viscoelastic solid-like materials at zero shear, limiting long-range diffusion, and demonstrating the characteristic shear-thinning behavior of flocculated systems. On the removal of shear stress, however, fluid gels have the capacity to rapidly recover their elastic properties. This lack of hysteresis is directly linked to the defined microstructures previously alluded to; because of the processing, reactive, non-gelled polymer chains at the particle interface facilitate interparticle interactions-similar to a Velcro effect. This rapid recovery of elastic properties enables bioprinting high-resolution parts from low-viscosity biomaterials, as rapid reformation of the support bed traps the bioink in situ, maintaining its shape. Furthermore, an advantage of agarose fluid gels is the asymmetric gelling/melting transitions (gelation temperature of ~30 °C and melting temperature of ~90 °C). This thermal hysteresis of agarose makes it possible to print and culture the bioprinted part in situ without the supporting fluid gel melting. This protocol shows how to manufacture agarose fluid gels and demonstrates their use to support the production of a range of complex hydrogel parts within suspended-layer additive manufacture (SLAM).

Influence of alkyl groups on the formation of softenable polysilsesquioxanes

Polysilsesquioxanes (PSQ) containing phenyl groups as substituents on the silicon atom can form transparent, hard and glassy materials at room temperature, which reversibly soften when heated above the glass transition temperature. Further increase in temperature leads to irreversible curing. With this property, polyphenylsilsesquioxanes can be assigned to the so-called melting gels. In contrast to the aromatic systems, polysilsesquioxanes with alkyl groups belonging to this class of materials are not known. To identify structural differences between aryl and alkyl systems, polyalkylsilsesquioxanes (RPSQs with R = methyl, ethyl, propyl, hexyl, octyl, decyl, dodecyl, hexadecyl, and octadecyl) were synthesised by a solvent-free, acid-catalysed hydrolysis and condensation reaction of alkyltrimethoxysilanes followed by thermal treatment at 300 °C under N2 atmosphere. The influence of the alkyl chain length on the structure built and the thermally initiated further condensation reactions were investigated via NMR, FTIR, TGA, DSC, SEC, and XRD. Depending on the alkyl chain length, the formation of highly crosslinked, insoluble systems (Me-PrPSQ), low molecular weight oligosilsesquioxanes in the form of cages (Hex-DecPSQ) to semicrystalline, lamellar layers (Dodec-OctadecPSQ) were detected. A low degree of condensation, inhibition of self-assembly and preferentially intermolecular condensation reactions were found to be crucial factors in the melting gel formation.Graphical So called melting gels are usually prepared by acid-catalysed hydrolysis and condensation of aromatic trialkoxysilanes. The final materials show a thermoplastic and a thermoset temperature regime based on the stabilisation of silanol groups in the material. In this study we transferred the typical synthetic conditions to alkyltrialkoxysilanes with different alkyl chain lengths and obtained completely changed structures of the synthesised polyalkylsilsesquioxanes compared to their aromatic counterparts. Depending on the chain length, densely cross-linked solids, viscous gels with cage-like structure and waxes with a lamellar composition were formed. Moreover, missing stabilisation of the OH groups and self-assembly phenomena, which favour the cage and semicrystalline layer formation were detected in the resulting materials, which leads to the loss of the typical melting gel properties.

18β-Glycyrrhetinic acid derivative-based metallo-hydrogels with highly selective and sensitive for histidine detection

Quantitative detection of His has aroused great interest in disease diagnosis since abnormal histidine (His) metabolism would cause a variety of serious diseases. However, exploiting a strategy with facile, highly selective, sensitive sensing and low-cost to monitor His remains a challenge. In this study, a series of novel metallo-hydrogels were successfully constructed, which were composed of 18β-glycyrrhetinic acid (GA) derivative (GA-O-09) with rare earth metal ions (Ce3+, Tb3+, Eu3+ and La3+). In addition, these metallo-hydrogels possessed excellent thermodynamics stability with the gel melting temperature (Tgel) ranging from 62.4 ± 0.49 °C to 67.4 ± 0.49 °C and remarkable pH stability over a range of pH values of 3–10. Interestingly, the Histidine (His)-loaded GA-O-09/Eu3+ hydrogel and the His-loaded GA-O-09/La3+ hydrogel displayed extraordinary fluorescence enhancement, in which the lowest fluorescence response concentrations (LODs) of the His-loaded GA-O-09/Eu3+ hydrogel and the His-loaded GA-O-09/La3+ hydrogel were 1.14 × 10-8 and 1.07 × 10-8 M, respectively. Therefore, the result showed that the study of the GA-O-09/Eu3+ and GA-O-09/La3+ hydrogels could provide a potential application for highly selective and sensitive detection for His.

Formulation and Evaluation of Paroxetine Hydrochloride Loaded Thermoreversible In situ Intranasal Gel

Aim The present work aimed to develop and evaluate Paroxetine HCl thermoreversible and mucoadhesive in situ intranasal gel.Methodology Carbopol 934P and poloxamer 407 have been utilized for the development of Paroxetine HCl thermoreversible and mucoadhesive in situ intranasal gel. The cold technique was used to formulate in situ intranasal gel. Evaluation of physico-chemical parameters clarity viscosity pH drug content and mucoadhesive strength was performed for intranasal in situ gel. In vitro drug release studies ex-vivo permeation studies and stability studies were conducted for all the formulations.Results A 19 wv of poloxamer 407 solution showed phase transition temperature at physiologic conditions 32ndash34o C. The mucoadhesive strength was found to be below 7000 dynescm2 till 0.4 wv concentration of carbopol 934P. Gelation temperature of formulation A4 was found to be satisfactory. Mucoadhesive strength in all the formulations was shown to be above 4000 dynescm2 . The gelation time and gel melting temperature of all the formulations showed uniformity. In vitro drug release was in the range of 54.8 to 83.22 in 8 h. Ex vivo drug release of the optimized A4 formulation was found to be 82.3 in 8h. All the formulations were found stable except A5.Conclusion Based on the results of in vitro and ex vivo studies the A4 formulation was found to be optimum. Thus the present work concluded that Paroxetine HCl thermoreversible in situ intranasal gel is safe and effective for treating depression.

Evaluating melting gel coatings for wearable metabolic sensors

New steps have been taken toward finalizing a novel wearable sensor for entirely non-invasive, continuous blood sugar monitoring via the low concentrations of acetone continuously emitted from human skin as a byproduct of metabolic activity. This sensor is based on a chemo-mechanical actuating polymer composite of the well-known conducting polymer polyaniline and cellulose acetate, which is a simple derivative of the incredibly proliferous and benign organic compound cellulose. The improvements reported here revolve around the application of a 65% methyltriethoxysilane – 35% dimethyldiethoxysilane melting gel to one side of the sensor, thereby isolating the sensor from ambient air and any interferents it might contain. Visual inspection shows that the melting gel does not prohibit functionality of the existing polyaniline-cellulose acetate sensor, and FTIR spectroscopy shows that no significant chemical changes are caused by application of the melting gel to the polyaniline-cellulose acetate sensor. • Composite-material wearable metabolic sensors continuously monitor skin-gas emissions. • Novel sensors are chemo-mechanical actuating polyaniline-cellulose acetate composite. • Organically modified siloxane melting gels create impermeable hydrophobic barrier. • Melting gel coatings are applied and consolidated without damaging composite sensors.

Development and qualitative evaluation of periodontal gel containing an antibacterial agent for periodontal disease

The present study aims at the development and evaluation of dental gel containing metronidazole non-biodegradable polymers for targeted delivery of drug and thus prolonging the action. Hot Method was used for the preparation of gel. Natural polymers like, Guar gum, Sodium alginate, Chitosan, Xanthan gum, Gellan gum were used in the formulations of gel. Prepared gels were evaluated for pH, rheological study, spreadability study, gelation, and gel melting study. At last Field Emission Scanning Electron Microscopy FESEM, Differential Scanning Calorimetry (DSC), Thermo Gravimetric Analysis (TGA), Texture Profile Analysis (TPA) have been done on an optimized gel formulation. All gels revealed pH ranged between 6.16 to 6.47, spreadability between 28.37 to 45.03 g.cm/sec, drug content between 90.01 to 99.10 % viscosity ranged between 3108.44 cps and 3645.47 cps and formulations F3 and F10 showed gelation temperature 39±0.12OC and 37±0.13OC respectively which is similar to the temperature of the body. Surface of the sample gels showed no drug particles, indicating a homogeneous mixture of polymers of drugs as well as natural agents. Formulation F10 containing Guar gum showed slower degradation in all media as compared to gels made of Sodium alginate, Xanthan gum, Chitosan, Gellan gum. DSC results revealed that the drug has the same state in the optimized formulation. TGA results showed that the formulation was found to have high stability in high-temperature settings. TPA results of optimized F10 revealed the parameters Mucoadhesive strength 92.54 ± 2.65 g, Hardness 25.34 ± 0.01N/mm², Compressibility 57.75 ± 0.40N mm, Adhesiveness−4.56 ± 0.26 N mm, Cohesiveness 0.83 ± 0.06. Hence, it is concluded that Metronidazole gel with gellan gum showed a longer degradation time and guar gum showed slower degradation in all over polymers used in gel formulations.

Investigation on the coacervation of fish scale gelatin hydrogel with seafood waste hydrolysates for the development of artificial fish bait: Physico-chemical, thermodynamic, and morpho-structural properties

The study dealt with the development of biopolymer based hydrogel artificial fish bait with hydrolysates derived from fish processing wastes. Fish scale gelatin (FSG) was used for the development of a hydrogel to which bioattractants extracted from seafood processing wastes of fish, squid and shrimp were added to prepare composite gels such as FSG-FH, FSG-SH and FSG-SPH, respectively. To understand the homogenesity and cross linking complexation of composite gels, the study aimed at investigating physico-chemical, thermodynamic, molecular and structural properties were analysed. The gel strength, melting point and thermal stability of the composite hydrogels were found to decrease marginally compared to the control gel, FSG. It could be understood that the crystalline structure at 2θ = 23° of the FSG-SH, and FSG-FH were not much altered compared to FSG gel. However, alteration in the crystalline structure in FSG-SPH was evident at 2θ = 27.3°. The TGA and DSC analysis revealed the reduction in the thermal stability of FSG on the addition of protein hydrolysates in the process of coacervation to get hydrogel based fish bait. Further, FESEM and AFM analysis indicated FSG-SH as the composite hydrogel with most compact and smooth surface was evident by Ra and Rq values. Among the composite gels, FSG-SH was found to have higher hydrophobicity due to enhanced gel structure. FTIR spectra of FSG and composite gels exhibitted similarity corresponding to amide-A, B, I, II and III bands. However, NMR analysis revealed the existence of notable difference with respect to chemical shift in the range of 7.0–7.75 ppm expressing the presence of aromatic protons of the amino acid phe and N–H protons of amide in all the composite gels. Further, NMR analysis confirmed the role of imino acids (δ CH2 & β CH2 protons) and hydrophobic amino acids (α-CH2 protons) in decrease the physical and thermal properties of the composite gels. The addition of protein hydrolysates with FSG was found to decrease the physical, thermal and structural properties, however improve the aromatic compounds of the composite gels.

Preparation of octenyl succinylated kappa-carrageenan; reaction optimization, characterization, and application in low-fat vegan mayonnaise

Kappa-carrageenan (KC) esterification reaction with octenyl succinic anhydride was optimized using response surface methodology, leading to the production of a food-based emulsifier. Modified kappa-carrageenan (KC-OSA) with different degrees of substitution (DS) (0.023 and 0.045) was produced, and their functional and structural properties were investigated. The results from FTIR and 1HNMR verified the successful occurrence of modification. The KC-OSA emulsions with both DS values were utterly stable after 30 days of storage, while KC failed to form emulsions. The viscosity, foaming properties, surface net charge, and gel opacity increased after modification and with an increase in its extent, while emulsion particle size and polydispersity index, gel melting temperature, and gel hardness decreased. Afterward, the KC-OSA (DS = 0.023) potential use was investigated as fat and egg yolk substitute in mayonnaise, which resulted in vegan mayonnaise samples with no phase separation after a month of storage at room temperature. Particle size measurements implied that the particle size of the mayonnaise sample was decreased with an increase in KC-OSA concentration. The results from the sensory evaluation showed that KC-OSA could be successfully implemented in low-fat vegan mayonnaise. The results from this study draw a bright horizon for the use of KC-OSA in the food industry.