Weak Gel Research Articles

Suspensions of attractive microcapsules: A noncolloidal fragile gel?

We investigated the rheological properties of suspensions of attractive microcapsules, which formed a weak gel at volume fractions ϕ as low as 0.1. These microcapsules, measuring 100 μm in diameter, were constructed with a droplet of positively charged chitosan solution protected by a membrane formed through the complexation of chitosan with a negatively charged surfactant. Iso-density matched suspensions were achieved by dispersing these microcapsules in silicone oils. Plate-plate rheometry revealed that these suspensions displayed a yield stress ranging from about 0.1 to 3 Pa for ϕ increasing from 0.1 to 0.5. At much higher stresses, the suspension viscosity was almost shear independent. Furthermore, these suspensions exhibited a frequency sweep signature akin to attractive colloidal suspensions, with a shear elastic modulus plateauing at low frequencies, indicative of an elastic microstructure within the suspensions. Remarkably, a degree of microstructural anisotropy, reminiscent of fragile matter, was evidenced by the transient fluidization of the suspension when the direction of applied stress, which remained below the yield stress, was reversed. Beyond the yield stress, both symmetric and asymmetric stress reversal experiments demonstrated that the suspension structure was influenced by the applied stress. It changed from an anisotropic and fragile network at low stress levels to a dispersion of isolated particles at high stress levels. We concluded that suspensions of attractive microcapsules could be classified as a fragile particulate gel, whose microstructure depends on the stress and its direction.

Topological structure, rheological characteristics and biological activities of exopolysaccharides produced by Saccharomyces cerevisiae ADT

Saccharomyces cerevisiae ADT is an edible fungus, with limited research on its exopolysaccharides (EPS). Three types of exopolysaccharides (EPS60, EPS80, and EPS100) were obtained through multiple purification steps using varying concentrations of ethanol in this study. The topological structure, rheological properties, and biological characteristics of EPS were investigated. High performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic resonance (NMR) analyses indicated that the three EPS are primarily made up of mannose with a small amount of glucose. Acetyl groups were also found, along with the presence of α-type pyranose and β-type pyranose. The Congo Red test and X-ray diffraction results reflected the absence of a triple helix structure and crystal properties. Atomic force microscopy (AFM) revealed the self-assembly of three exopolysaccharides into various topological structures under different concentration gradients, and a clear network structure of entangled chains was observed. EPS60, EPS80 and EPS100 displayed pseudoplasticity, weak gel behavior and thermal stability. Significantly, EPS exhibited antioxidant activity in a dose-dependent manner and showed no acute cytotoxicity to RAW264.7 and HEK293T cells. Therefore, EPS in this study is anticipated to be utilized in natural antioxidants, medications, and functional materials.

Optimization and characterization of physicochemical, morphological, structural, thermal, and rheological properties of microwave-assisted extracted pectin from Dillenia indica fruit.

Microwave-assisted extraction of pectin from Dillenia indica (DI) fruit was optimized using Box-Behnken design to maximize yield and quality. Parameters such as solid:solvent (1:10-1:30), microwave power (200-600W), and extraction time (4-10min) were varied to determine the optimal conditions. Through experimentation, the optimized extraction parameters were identified as 1:23.66 solid:solvent, 400W microwave power, and 7min of extraction time, under which the predicted yield and equivalent weight were 19.68% and 915.93, respectively. The optimized conditions were validated experimentally (yield:19.4±0.35%) and equivalent weight:914.57±0.62), showing close agreement with predicted values. Physicochemical properties of the extracted pectin were determined, revealing an effective pore radius of 0.263±0.005mm and a swelling index order of: water(1)>pH6(0.7)>HCl(0.3). Moisture content was measured as 7.23±0.25%, while ash content was found to be 2.23±0.25%. Further analysis included the determination of methoxyl value, anhydrouronic acid content, degree of esterification, and protein content, which were 9.61±0.31%, 73.56±1.86%, 74.15±0.28%, and 1.16±0.16%, respectively. Monosaccharide composition revealed presence of neutral sugars, glucose, arabinose and rhamnose and molecular weight was 71,489g/mol. Morphological characteristics, assessed using scanning electron microscopy, showed a rough, irregular surface of DI fruit pectin. Fourier-transform infrared spectroscopy (FTIR) indicated similarity to standard high methoxyl pectin, while nuclear magnetic resonance (NMR) confirmed characteristic functional groups. Thermal behaviour, determined via differential scanning calorimetry (DSC), exhibited endothermic and exothermic transitions at 83.6°C and 260.027°C, respectively. Rheological and functional properties revealed DI fruit pectin solution as a non-Newtonian fluid with shear thinning behaviour, forming weak gels and that its emulsion capacity increased with increase in pectin concentration. Overall, this study provides a comprehensive characterization of microwave-assisted extracted pectin from Dillenia indica fruit, offering insights into its potential applications in food industries.

Preparation of dried nanoemulsion formulation by electrospinning.

Dry eye disease is a multifactorial condition characterized by a loss of homeostasis of the tear film. Among the various treatment approaches, the application of ophthalmic oil-in-water nanoemulsions with incorporated anti-inflammatory drugs represents one of the most advanced approaches. However, the liquid nature of nanoemulsions limits their retention time at the ocular surface. Transforming the nanoemulsions into a dry form that would disperse rapidly in the tear fluid would improve the retention of the drug at the ocular surface. The aim of this study was to investigate electrospinning as a method for the preparation of a solid eye preparation based on nanoemulsion loaded with the anti-inflammatory drug loteprednol etabonate. Four nanoemulsions differing in oil-to-surfactant ratios were incorporated in hydrophilic nanofibers based on polyethylene oxide, poloxamer 188, and Soluplus®. The dried nanoemulsions in the form of nanofibers dispersed readily on contact with aqueous medium, resulting in a dispersion of nanometre-sized droplets with average size comparable to the average droplet size of the initial nanoemulsions. A rheological study revealed the predominant elastic behavior of the dispersed nanofibers, which indicates the formation of a weak gel after the dispersion of the dried nanoemulsion in tear fluid at the ocular surface. The biocompatibility of the dried nanoemulsions in the form of nanofibers after a single and multiple-dose application was confirmed using the 3D HCE-T model of the stratified epithelium of the human cornea, suggesting that this innovative solid eye preparation could represent a new approach to the treatment of dry eye disease.

Cell wall polysaccharides from macauba pulp (Acrocomia aculeata L.): Fractionation and characterization of their chemical and rheological properties.

Macauba fruit pulp (Acrocomia aculeata) is an emerging oil source. After de-oiling, the macauba pulp meal (MPM) offers a dietary fiber content of 40-50 %, which mainly comprises cell wall polysaccharides (CWP). The present work aimed to assess the potential of MPM as an innovative source of sustainable food polysaccharides. To this end, the macauba CWP were fractionated into water-soluble galactoglucomannans (21.7 %), calcium- and ester-bound pectins (3.4 %), loosely-bound xyloglucans (27.6 %), strongly-bound xylans (6.5 %), and a cellulose-rich fraction (39.3 %). The galactoglucomannans produced shear-thinning aqueous dispersions with an increase in consistency index from 3.03·10-2 to 3.58·101 Pa·sn by increasing the concentration from 1.0 to 5.0 %. The galactoglucomannans dispersions showed semi-dilute behavior, evidenced by relaxation times ranging from 1.24·10-2 to 1.17 s for concentrations from 2.5 to 10.0 %. Macauba pectins and xyloglucans showed weak gel behavior, with an increase in yield stress from 3.20·10-1 to 1.04·102 Pa and from 7.01·10-2 to 1.35·102 Pa for dispersions at 2.5 to 10.0 %, respectively. 2.5 to 5 times higher concentration of macauba polysaccharides is needed to obtain rheological behavior similar to guar and xanthan gum. The thickening and gelling properties of macauba CWP highlight their potential as thickeners and stabilizers for the food industry.

The Influence of the Ionic Environment on Rheological Properties of Acidified Micellar Casein Gels.

Membrane filtration allows for the physical separation of milk components and can be used as a single process or in multiple steps to recombine different component streams to create cultured milk products with unique functional properties. In this study, micellar casein (MC) powder, was dispersed at 4 and 8% (wt/wt) protein in water, NaCl (10 - 100 mmol kg-1) or ultrafiltered milk permeate (5.6%, wt/wt). MC is a dairy powder obtained by microfiltration that is mostly depleted of whey proteins and soluble salts. This study was conducted in several parts to investigate the impact of dispersant (solvent) on the pH of gelation and rheological properties of acid gels made from MC. In the initial phase, we prepared model acid gels by acidifying MC at cold temperatures (<4°C) and subsequent warming to 42°C to induce gelation. We also prepared MC gels by yogurt fermentation using commercial starter cultures incubated at 42°C. All MC samples were prepared in duplicate. Gel formation in MC samples occurred as high as pH 5.7 in the cold-acidified milk system. The pH of gelation was highly dependent on the protein level, dispersant used, and concentration of added salts. With increasing concentrations of added NaCl, a decrease in the pH of gelation was observed (from pH 5.7 to below 4.6) as well as a decrease in gel strength (from 175 to <1 Pa). Acid gelation was very dependent on the type of dispersant used to rehydrate the MC. At similar conductivities, MC dispersions with higher protein (8%) levels formed gels at higher pH values compared with lower protein (4%) dispersions. In microbially fermented yogurts, a maximum loss tangent value was observed during acidification in MC gels prepared with low-to-moderate ionic strength. This was unexpected as the concentration of denatured whey proteins should be very low in these MC systems. No maximum loss tangent value was observed for MC samples dispersed in 100 mmol kg-1 NaCl, as they did not form a gel until pH 4.5. Gel samples with large maximum loss tangent values also exhibited a more open, porous gel microstructure, which was indicative of weak gels that can be prone to syneresis. Results from this study could help dairy manufacturers to design specialty milk powders that have unique functionality when used for acid milk gels, like yogurt.

L-Cysteine/Silver Nitrate/Iodate Anions System: Peculiarities of Supramolecular Gel Formation with and Without Visible-Light Exposure.

In this study, novel anion photo-responsive supramolecular hydrogels based on cysteine-silver sol (CSS) and iodate anions (IO3-) were prepared. The peculiarities of the self-assembly process of gel formation in the dark and under visible-light exposure were studied using a complex of modern physico-chemical methods of analysis, including viscosimetry, UV spectroscopy, dynamic light scattering, electrophoretic light scattering, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. In the dark phase, the formation of weak snot-like gels takes place in a quite narrow IO3- ion concentration range. The visible-light exposure of these gels leads to an increase in their viscosity and dramatic change in their color. The morphology of gels alters after light irradiation that is reflected in the formation of a huge number of spherical/elliptical particles and the thickening of the fibers of the gel network. The interaction of CSS with IO3- anions has features of a redox process, which leads to the formation of silver iodide/silver oxide nanoparticles inside and on the surface of CSS particles. CSS possesses selectivity only to IO3- anions compared to many other inorganic ions relevant for humans and the environment. Thus, the CSS/IO3- system is non-trivial and can be considered as a novel low-molecular-weight gelator with photosensitive properties, as another way to produce silver iodide nanoparticles, and as a new approach for IO3- ion detection.

Colloidal state-based studies on the chloride salts of magnesium- and calcium-induced coagulation of soymilks.

Chloride salts (MgCl2 and occasionally CaCl2) coagulation of the heated soymilks is the key step in manufacturing traditional tofu. In this study, colloidal state diagrams were constructed first, and then the effects of processing parameters, including coagulant concentration, preheating intensity, protein concentration, and coagulation temperature as well as the intrinsic properties (phytate concentration) on the microstructure, protein coagulability, and water holding capacity (WHC) were investigated to gain an overall framework understanding of the Mg2+ and Ca2+ coagulated soymilk process. As the variables changed, the coagulated soymilks displayed one of the following states: colloidal suspension, flocs, weak gel, and strong gel. The microstructures of the coagulated systems also changed to different features with the variation in processing parameters and phytate concentrations. Several interesting results were obtained. It was found that the transformations from colloidal suspension to gel state were usually corresponding to the increase of particle size, the decrease of porosity, and a sharp increase in protein coagulability. The colloidal states of Mg2+ and Ca2+ coagulated soymilks were usually different, but their microstructures were similar. With the increase of protein concentration, the protein coagulability decreased but the WHC was enhanced. The presence of high phytate contents led to form small protein agglomerates, which resulted in worse protein coagulation and WHC. It is expected that this study will deepen the understanding of chloride salts coagulation process.

Impact of process conditions and type of plant protein on aggregate formation with whey protein and resulting ricotta-like gel texture

Aim of the study was to investigate the effect of process conditions and type of plant protein on protein aggregation and texture of hybrid ricotta alternatives. Four different plant proteins (soy, pea, lupin, potato) were used and first underwent a pre-treatment to increase solubility, followed by thermally-induced pre-aggregation of the hybrid systems with β-lactoglobulin-rich whey protein at varying pH and temperature. Aggregates were analysed via particle size distribution and SDS-PAGE. For production of the ricotta alternative, acidification and subsequent thermal coagulation formed the protein gel network. Texture analysis and visual evaluation of macroscopic structure was carried out.Results showed that aggregate size significantly affects gel strength. For soy-whey mixtures pH during pre-aggregation was the main factor affecting aggregate size, with a favourable diameter of 5 μm and a corresponding gel strength to whey-based ricotta of 0.9 N. Pea protein generally behaved similar to soy protein due to the similarity in protein composition and structure. In contrast, use of lupin resulted in a weaker gel, due lupin’s dense molecular structure and high denaturation temperature. Potato-whey hybrid systems formed large insoluble aggregates, which as a consequence did not contribute to gel formation. In summary, the results of the present study show that a variation of the protein type in hybrid ricotta alternatives requires process adaptations, but at the same time allows the creation of new gel structures for hybrid cheese alternatives.

Rheological Properties of Weak Gel System Cross-Linked from Chromium Acetate and Polyacrylamide and Its Application in Enhanced Oil Recovery After Polymer Flooding for Heterogeneous Reservoir.

Long-term polymer flooding exacerbates reservoir heterogeneity, intensifying intra- and inter-layer conflicts, which makes it difficult to recover the remaining oil. Therefore, further improvement in oil recovery after polymer flooding is essential. In this study, a weak gel system was successfully synthesized, and possesses a distinct network structure that becomes more compact as the concentration of partially hydrolyzed polyacrylamide increases. The network structure of the weak gel system provides excellent shear resistance, with its apparent viscosity significantly higher than that of partially hydrolyzed polyacrylamide solution. The weak gel system exhibits typical pseudo-plastic behavior, which is a non-Newtonian fluid as well as a viscoelastic fluid. Additionally, the weak gel system's elasticities exceed its viscosities, and longer crosslinking time further enhances the viscoelasticity. The weak gel system achieves superior conformance control and enhanced oil recovery in highly heterogeneous reservoirs compared to partially hydrolyzed polyacrylamide solutions. The weak gel system is more suited to low-permeability reservoirs with strong heterogeneity, as its effectiveness in conformance control and oil recovery increases with greater reservoir heterogeneity. Enhanced oil recoveries of the weak gel system in low-permeability sandpacks increase from 22% to 48% with a rise in permeability ratios from 14.39 to 35.64 after polymer flooding.

Advanced valorization of cocoa (Theobroma cacao L.) pod husks through 40 kHz-ultrasonic bath assisted extraction of pectins

Theobroma cacao is an economically relevant agricultural commodity. In the Amazon region, Peru boasts 6 of the 10 genetic cacao families of the world. Cocoa pod husk (CPH), the main agro waste (67–76% of fruit), and its three constituent layers, endocarp (END), mesocarp (MSO) and epicarp (EPI) tissues, were separately evaluated, after drying and milling, as potential sources of pectin, a valuable industrial additive. A 40 kHz-ultrasonic bath (160 W; 100% amplitude) pretreatment (15 min; 50 °C) of tissue powders with citric acid solution (pH 3.0) followed by magnetic stirring (50 °C - 1400 rpm; 60 min for CPH, EPI and MSO or 345 min for END) gave the highest pectin yields, together with the 1:150 (g/mL) powder to solvent ratio for CPH and EPI pectins, and 1:75 (g/mL) for MSO and END pectins. END pectins were homogalacturonans with an 86-84 % uronic acid (UA) content, while the rest had ≈ 65 % UA, all with low degrees of methylesterification (5.26–35 %) and acetylation (9.56–30 %). Pectins exhibited high molecular weights (5.57–7.05 MDa). Phenolic compounds (216–4643 μg/g) and methylxanthines (theobromine, caffeine) were co-extracted with pectins. Mechanical spectra of 1.50 % w/v aqueous pectin with 30 mg Ca2+/g of UA revealed “weak gel” type networks, most structured for END pectin, but “dilute solution” for CPH pectin. CPH and its constituent tissues can be valorized as sources of thickening and gelling pectins.

Investigating the role of lemon peel fiber in the casein gelation mechanism of low-fat yogurt

Incorporation of insoluble dietary fibers (IDFs) into yogurt can serve as both a nutritional supplement and texture modifier. However, the understanding of the interaction between IDFs and casein particles in yogurt, as well as their effect on the gelation mechanism of casein particles, remains limited. This study investigated the impact of varying contents of insoluble lemon peel fiber (LPF) on the casein gelation in low-fat yogurt. The gelation process of casein was monitored via oscillatory rheology, and the critical gel point was determined from time sweep curves. The post-gelation process was analyzed through the percolation model, and the topological structure after gelation was quantified using skeleton analysis. The incorporation of moderate content of LPF was found to reduce fermentation time (with the highest decrease being up to 1.2 h). This effect could be attributed to the enhanced main intermolecular forces (hydrophobic interactions and disulfide bonds), as well as the formation of casein-LPF-casein linked clusters with an elevated gelation rate exponent (α) value. These factors facilitated gel formation. Moreover, a moderate content of LPF facilitated cross-linking between caseins through a bridging effect, resulting in the development of a densely interconnected network with enhanced link density (88.25%) and reduced pore fraction (7.71%). Consequently, this led to a significant 17.6% inhibition in wheying off rate compared to low-fat yogurt without LPF during a 21-day storage time. However, the formation of weak or coarse gels was observed when the LPF content was low or high, the gelation rate was excessively rapid (exponent α = 3.05), or the presence of steric hindrance effect was present. The findings offered valuable insights for the application of insoluble particulate components in the food industry.

Effect of the Ratio of Protein to Water on the Weak Gel Nonlinear Viscoelastic Behavior of Fish Myofibrillar Protein Paste from Alaska Pollock.

The linear and nonlinear rheological behaviors of fish myofibrillar protein (FMP) paste with 75%, 82%, and 90% moisture content were evaluated using small-amplitude oscillatory shear (SAOS) and large-amplitude oscillatory shear (LAOS) tests. SAOS revealed pastes with 75% and 82% moisture exhibited solid-like behavior, characterized by higher storage modulus (G') than loss modulus (G″), indicative of weak gel properties with a strong protein interaction. In contrast, the 90% moisture content showed more viscous behavior due to weakened protein-protein entanglements. The frequency exponent (n' and n″) from the power law equation varied slightly (0.24 to 0.36), indicating limited sensitivity to changes in deformation rate during SAOS. LAOS tests revealed significant structural changes, with Lissajous-Bowditch curves revealing early nonlinearities at 10% strain for 90% moisture content. Decomposed Chebyshev coefficients (e3/e1, v3/v1, S, and T) indicated strain stiffening at lower strains for the 75% and 82% moisture pastes (i.e., < 50% strain for 75% and < 10% strain for 82%), transitioning to strain thinning at higher strains. Additionally, numerical model confirmed the predictability of the 3D printing process from the nonlinear rheological data, confirmed the suitability of the 75% and 82% moisture pastes for applications requiring structural integrity. These insights are essential for optimizing processing conditions in industrial applications. The findings suggest that the 75% and 82% moisture pastes are suitable for applications requiring structural integrity, while the 90% moisture paste is ideal for flow-based processes. These insights are essential for optimizing processing conditions in industrial applications.

One-pot fabrication of sodium deoxycholate based supramolecular self-healing antibacterial double network hydrogels

Double network (DN) hydrogels have emerged as a significant technology for enhancement of mechanical strength of weak supramolecular gels. In the present study, we report the one-pot route for design of a low molecular weight gelator based DN hydrogel wherein sodium deoxycholate (NaDC) forms the primary network entangled with agar matrix. Various compositions of the reported agar-NaDC hydrogels were examined through FTIR, sol-gel transition temperature (Tsg), XRD, circular dichroism (CD), scanning electron microscopy (SEM), hydrophobicity probe studies, Zeta potential studies and rheology measurements. Analysis of all studies together reveal that 1 mg/ml agar-NaDC DN hydrogel is the optimum composition that exhibits dense networking with primarily β-sheet like structure, highest mechanical strength as well as self-healing characteristics with reversed optical activity and highest Tsg. Antibacterial activity studied using inhibition zone method suggests that 1 mg/ml agar-NaDC gel demonstrates significant bactericidal effect unlike the pure gel with an inhibition zone of ∼25 mm against E.coli after 24 h and ∼32 mm after 48 h incubation. The antibacterial activity was unique for this composition of the DN hydrogel which is attributed to its reversal in optical activity exhibiting positive cotton effect resulting in stronger interaction with the bacterial cell wall. Additionally, nearly 2 times reduced water absorption capacity of the 1 mg/ml agar-NaDC DN hydrogel compared to pure NaDC hydrogel ensures the retention of its mechanical strength as well as other properties in high moisture containing environment. Hence, the 1 mg/ml agar-NaDC DN hydrogel holds appreciable potential as a novel strong supramolecular self-healing antibacterial hydrogel with sustained release characteristics primarily important for biomedical applications.

Amelioration of extremely acidic environment of soy protein amyloid fibrils to enhance gelation performance by dialysis strategy: Effects of pH and ions

The application of soy protein amyloid fibrils (SAFs) to food industrialization field has received focused attention because of their advantages such as ordered supramolecular structure and anti-proteolytic properties. However, the comparatively weak gelation properties of SAFs make it difficult to form self-supporting hydrogels, limiting its potential for future applications. Additionally, the extremely acidic environment (pH 2) of SAFs hinders their practical application in the food pH range (4–7). To address this issue, a dialysis strategy was utilized to enhance the gel structure of SAFs in this paper. The SAFs were dialyzed by deionized water and zinc ions solutions with four different pHs (2, 4, 7, and 9), and the impact of various dialysates on rheological properties, water distribution, and microstructure was investigated. The results demonstrated the method significantly improved gelation properties and modified the extremely acidic environment of SAFs. Various samples were continuously deacidified during dialysis in solutions of different pHs (4, 7, and 9), transforming from pH 2 to a higher pH value. Visual images exhibited that self-supporting hydrogels can be formed by SAFs just at a low concentration of 3% (wt). SAFs-Zn2+-9 hydrogel exhibited the highest storage modulus with a 500-fold compared to SAFs-2. Notably, the SAFs-H2O hydrogels were fabricated without any exogenous substances, in which the storage modulus of SAFs-H2O-9 increased by over 300 times. AFM images demonstrated that the shift from long rigid fibrils to short flexible fibrils induced tightly entanglement among fibrils, which improved gelation performance. Moreover, the transform in pH and the incorporation of ions caused the hydrogels to show dense network structure and strong water retention capacity. The ingenious insights were provided for improving the gelation performance of SAFs and modifying the polar acidic environment in the study, fully exploiting the potential of SAFs as edible ingredients for food applications.

Gelation properties and swallowing characteristics of heat-induced whey protein isolate/chia seed gum composite gels as dysphagia food

Soft gels based on protein-polysaccharide composite systems play a crucial role in the dietary management of people with dysphagia. The effect of chia seed gum (CSG) on the gelling and swallowing properties of heat-induced whey protein isolate (WPI) gels (3.125–75 mg/mL) was investigated. The results showed that adding CSG reduced the gelation concentration of WPI and weak gels could form at 12.5 mg/mL WPI concentration. In addition, the viscoelasticity and water-binding capacity of the WPI/CSG composite gels were gradually enhanced with increasing WPI concentrations. The WPI/CSG composite systems can be classified as level 2–5 dysphagia-oriented foods according to the International Dysphagia Diet Standardization Initiative (IDDSI) framework. The incorporation of CSG promoted the cross-linking of protein aggregates and the formation of compact and continuous network structures, resulting in improved gelling properties of composite systems. This study contributes to the development of novel soft gel-type dysphagia foods with better textural characteristics.

The Assessment of the Possibility of Using Yellow Mealworm Powder in Chicken and Pork Pâté Production

Meat delicatessen products, including pâtés, are important for consumers’ daily diets. However, due to the complex recipe composition, pâtés can also contain allergens such as gluten. Simultaneously, powdered edible insects are increasingly used to reformulate food products. Therefore, the paper aimed to investigate the feasibility of replacing wheat flour (total content: 9% w/w) with yellow mealworm powder (3:0, 2:1, 1:2, and 0:3) in chicken and pork pâtés and determine its effect on their quality properties. The rheological properties of pâté batter, as well as texture, color parameters, and microbiological and sensory characteristics of pâtés, were assessed. All prepared pâté batters were identified as weak gels. Furthermore, all the examined pâtés met the microbiological quality requirements. Adding yellow mealworm powder to the formulation weakened the pâté structure, resulting in significantly lower shear force and increased spreadability. In addition, it led to a darker and more gray color of the pâtés. It may be seen as indicating no preservatives or as resembling a typical pork pâté. It has been demonstrated that the complete replacement of wheat flour with insect powder significantly reduced the sensory quality of chicken and pork pâtés.

Research and Application of Smart Temporary Plugging Gel for Small Casing Cementing in Changqing Oilfield

Abstract In response to the serious leakage and low productivity recovery rate after cement plugging during the secondary cementing process of repairing small casing in the old wells of Changqing Oilfield, this study draws on the theory of shielding and temporary plugging in the drilling process to propose an adaptive smart temporary plugging gel technology. This technology has developed a weak gel suspension base liquid and synthesized a polymer material with good viscosity, high deformability, high sealing strength, and the ability to automatically hydrate and degrade at a certain temperature. It synergistically cooperates with other auxiliary temporary plugging materials to form an adaptive and self-degrading temporary plugging gel system, which can quickly form a sealing barrier at severely leaking areas such as corroded perforations, effectively preventing cement slurry leakage during subsequent cementing processes, shortening the operation cycle, and protecting the reservoir. Experimental evaluations indicate that the gel system can withstand pressure up to 15MPa, degrades in 7-10 days, and achieves a reservoir recovery rate of over 90%, effectively achieving the goals of plugging, releasing, and minimizing reservoir pollution. It has been applied in 30 wells in the Changqing Oilfield, with a success rate of over 96% in the first plugging operation, and an average production recovery rate of over 95%, significantly protecting the oil reservoir.

Multifunctional 3D pristine graphene with tunable electromagnetic properties via self-assembly strategy

Nowadays, there is an urgent demand for multifunctional materials with tunable properties to meet the requirements of intricate environments with alternating temperatures and electromagnetic conditions. Pristine graphene is a highly promising electromagnetic material owing to its intrinsic advantages. However, issues related to aggregation and weak gelation capability would hinder the fabrication and advancement of multifunctional pristine graphene. Herein, multifunction properties are first integrated into one 3D structured pristine graphene via a self-assembly method. By regulating the microstructures, 3D structured pristine graphene can exhibit a range of electromagnetic properties, including wave transmission (wave transmittance of 88 %-93 %), electromagnetic wave (EMW) absorption (reflection loss of −50.70 dB), and electromagnetic interference (EMI) shielding (shielding effectiveness (SE) of ∼37.90 dB), which are not available in existing graphene materials. Furthermore, the 3D structured pristine graphene exhibits mechanical stability and thermal performances to guarantee a stable and durable electromagnetic response for complex environmental applications. The outstanding multifunction can be attributed to the low defects and controllable microstructures of pristine graphene. This work supplies an inspiration for the development of multifunctional graphene materials as well as the microstructure design of 3D pristine graphene.

Improving the rheological properties of ultra-processed powdered goat milk beverage using texture additives.

This study aimed to investigate the static and dynamic rheological properties of an ultra-processed powdered goat milk beverage containing carboxymethyl cellulose (CMC), guar gum (GG), and xanthan gum (XG), using a mixture design. Fourteen samples were evaluated, in addition to the original beverage. The flow curves classified the fluids as non-Newtonian and characterized all the reconstituted beverages with pseudoplastic behavior, precisely due to the addition of hydrocolloids that increased the viscosity, and the fresh beverage sample showed the behavior of a dilatant fluid. The stress sweep verified the changes in the storage module (G') and the loss module (G″), the G' ranged from 1.97 to 20.36 (Pa) and the G″ ranged from 5.94 to 11.30 (Pa), demonstrating that there was the formation of beverages with elastic and viscous behaviors. The results showed a synergistic effect between the texture improvers, and the formulations with GG identified a greater effect on the tension. The frequency sweep tests showed that the behavior of the samples was that of a weak gel; however, when subjected to a certain frequency, the values of G' exceeded the value of G″, becoming a sample with more elastic characteristics and consequently, presenting the behavior of a stronger gel. Finally, according to the data presented, it is assumed that formulations containing GG and xanthan gum may produce desirable consumer properties for the reconstituted goat milk drink. Samples with a higher concentration of GG exhibited improved rheological performance, characterized by greater consistency, increased resistance to tension, and higher viscosity at low frequencies. PRACTICAL APPLICATION: The powdered goat milk drink is an innovative product that meets the demands of the food industry and consumers by offering a nutritious and sustainable beverage alternative.