The isolation and characterisation of protein from nine edible insect species.

The increasing global population and consumer demand for protein pose a serious challenge to the provision of protein-rich diets. Insect farming has been suggested to have a lower environmental impact than conventional animal husbandry which makes insect consumption a more sustainable solution to meet the growing world population's protein requirements. However, there is a reluctancy in the adoption of insect protein especially in the Western diets as whole insect consumption is often met with disgust and resentment. To mitigate against the feeling of disgust and resentment, there have been suggestion to include insects as an ingredient in product development. However, for this to be successfully carried out, the techno-functional properties of insect protein need to be characterised. Therefore, the aim of this study was to isolate and characterise proteins from nine edible insect species. Protein was isolated from nine edible insect species and characterised in terms of the protein content and molecular weight distribution. As crickets are the most common insect food source, the functional characterisation (foaming and emulsification) of protein extracted from house cricket (HC) supernatant protein (SP) was investigated in comparison to commercial whey protein (WP) and pea protein isolate (PPI). The protein content of the buffalo worms and yellow meal worms was significantly (P = 0.000) higher than other insect species such as wild black ants, queen leaf cutter ants, and flying termites. The molecular weight distribution of the nine edible insect species varied from ~ 5 to 250 kDa. HC SP foaming capacity was fourfold and threefold higher than that of WP and PPI respectively. The emulsification potential of HC SP was 1.5 × higher than PPI. The HC protein extract shows promising potential for use in the food industry and represents a potential vehicle for the introduction of insect protein into the diet of societies that are not accustomed to eating insects.

Foam Stabilization Process for Nano-Al2O3 and Its Effect on Mechanical Properties of Foamed Concrete.

Foamed concrete is increasingly utilized in engineering due to its light weight, excellent thermal insulation, fire resistance, etc. However, its low strength has always been the most crucial factor limiting its large-scale application. This study introduced an innovative method to enhance the strength of foamed concrete by using nano-Al2O3 (NA) as a foam stabilizer. NA was introduced into a foaming agent containing sodium dodecyl sulfate (SDS) and hydroxypropyl methylcellulose (HPMC) to prepare a highly stable foam. This approach significantly improved the foam stability and the strength of foamed concrete. Its drainage volume, settlement distance, microstructure, and stabilizing action were investigated, along with the strength, microstructure, and hydration products of foamed concrete. The presence of NA effectively reduced the drainage volume and settlement distance of the foam. NA is distributed at the gas-liquid interface and within the liquid film to play a hindering role, increasing the thickness of the liquid film, delaying the liquid discharge rate from the liquid film, and hindering bubble aggregation, thereby enhancing foam stability. Additionally, due to the stabilizing effect of NA on the foam, the precast foam forms a fine and uniform pore structure in the hardened foamed concrete. At 28 d, the compressive strength of FC0 (0% NAs in foam) is 2.18 MPa, while that of FC3 (0.18% NAs in foam) is 3.90 MPa, increased by 79%. The reason for this is that NA promotes the formation of AFt, and its secondary hydration leads to the continuous consumption of Ca(OH)2, resulting in a more complete hydration reaction. This study presents a novel method for significantly improving the performance of foamed concrete by incorporating NA.

Experimental Investigations and MD Simulation on Nanoparticle-Enhanced CO2-Responsive Foam (NECRF): Implications on CO2-EOR.

CO2-responsive foam (CRF) is a highly promising candidate for CO2-enhanced oil recovery (CO2-EOR) because it displays higher stability than the surfactant-stabilized foam owing to the formation of robust wormlike micelles (WLMs) upon exposure to CO2. In this work, the nanoparticle-enhanced CO2-responsive foam (NECRF) was properly prepared using lauryl ether sulfate sodium (LES)/diethylenetriamine/nano-SiO2, and its interfacial properties and EOR potential were experimentally and numerically assessed, aiming to explore the feasibility and effectiveness of NECRF as a novel CO2-EOR technique. It was found that the interfacial expansion elastic modulus increased 6-fold after CO2 stimulation. The modulus continued to increase with the introduction of nano-SiO2 owing to the pronounced synergistic effect of WLMs and nanoparticles. In addition to increasing the viscosity of the foaming liquid, WLMs and nano-SiO2 enhanced the shearing resistance of the NECRF as well. Calculations demonstrated that both the coarsening rate and the size distribution uniformity coefficient of NECRF were markedly lower than that of the LES foam, which subsequently inhibited NECRF decay and greatly improved its dynamic stability. Besides, molecular dynamics simulation revealed that adding inorganic salts to NECRF could notably enhance the foaming performance due to the intensified hydration of surfactant head groups and reduced binding energy of neighboring molecules. Nuclear magnetic resonance-assisted core flooding experiments validated the exceptional capacity of NECRF to sweep the low-permeability region and improve the conformance profile. Overall, these findings may provide valuable insights into the development and application of novel materials and strategies for the CO2-EOR.

Chickpea aquafaba: a systematic review of the different processes for obtaining and their nutritional and technological characteristics.

Aquafaba is the residual water from cooking chickpea in water. It has a high gelling ability, allowing it to create stable gels. However, those functional properties depend on the legume composition, genotype, cooking time, pressure, and temperature. This study aimed to evaluate the different processes for obtaining aquafaba and compare their nutritional composition and technological characteristics using a systematic review. The authors performed the systematic review by performing specific search strategies for Scopus, Web of Science, Pubmed, Lilacs, Google Scholar, and ProQuest. A total of 17 studies were analyzed. Of them, 17.64% (n = 3) used the wastewater from canned chickpeas, 17.64% (n = 3) compared the wastewater of canned chickpeas and dry grains, and 58.82% (n = 10) used dry chickpeas. Studies used different methods to analyze the protein content. The most used (n = 5) was the Association of Official Analytical Chemists (AOAC). The aquafaba presented carbohydrates at 2.03-2.59 g/100ml; protein at 0.0.8-2.8 g/100ml; and fat at 0.07-0.1 g/100ml. In general, preparing aquafaba followed: soaking (8-10 h at 4 °C-1 chickpea: 4 water), pressure cooking (30 min-2 chickpea: 3 water), and refrigerating (24h/4 °C). In general, the results showed the following steps to prepare aquafaba: soaking for 8-10 h at 4 °C at the proportion of 1:4 (chickpea:water), pressure cooking for 30 min in the proportion of 2:3 (chickpea: water), and refrigerating 24 h/4 °C. These procedures in a homemade aquafaba presented the best results, considering foam development and higher stability. The aquafaba from canned chickpeas has a higher foam-ability and lower emulsion properties than homemade cooking aquafaba. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05920-y.

Effect of catheter needle caliber on polidocanol foam stability in foam sclerotherapy.

Background: Although sclerotherapy is widely used to treat vascular malformations (VMs), it is associated with several challenges. One significant issue is the insufficient understanding of the influence of various factors on the stability of polidocanol (POL) foam used in sclerotherapy. Objective: This study aimed to explore the effect of the catheter needle caliber on foam stability when using POL with or without hyaluronic acid (HA) for the treatment of VMs. Methods and materials: The Tessari method generated sclerosant foam using POL both with and without HA. We used catheters and syringe needles of various calibers, and the resulting foam was transferred into new syringes to facilitate a comparison of foam stability. Foam half-life (FHT) was utilized as a metric to assess foam stability. Results: The study found that narrower needle calibers produced a more stable foam when POL was used alone; however, no significant effect was observed when HA was added. Furthermore, when the foam was expelled using catheters and syringe needles of the same size, no noticeable changes in the stability were observed. Conclusion: When choosing needles of varying calibers, their effect on foam stability should be carefully considered, particularly when the foam contains HA.

Surfactant foam injection for remediation of diesel-contaminated soil: A comprehensive study on the role of co-surfactant in foaming formulation enhancement.

Aqueous foam injection is a promising technique for in-situ remediation of soil and aquifers contaminated by petroleum products. However, the application efficiency is strongly hindered by foam's instability upon contact with hydrocarbons. Addressing this, we propose a new binary surfactant mixture of Sodium Dodecyl Sulfate (SDS) and Cocamidopropyl Hydroxysultaine (CAHS). This study investigates CAHS's role as a co-surfactant in enhancing foam stability against antifoaming diesel oil under static and dynamic conditions. Using a dynamic foam analyzer (DFA-100), we assessed static foam's stability by monitoring decay profiles and bubble growth over time. The results revealed that the highest stability can be reached at a CAHS to SDS ratio of 50:50, increasing the half-life of the foam by 7.7 times. Remarkably, our analyses at bulk and bubble scales also elucidated the mechanisms behind the enhanced foam stability of the proposed binary surfactant mixture in the absence and presence of diesel. Additionally, in a 1D sand column, the SDS-CAHS mixture demonstrated more than twofold improvement of the Resistance Factor, attributed to the better survival of the lamellae due to the reduced rate of their destruction. This formulation also yielded a recovery improvement of >10 % compared to SDS foam. The significant improvements in stability and performance of the SDS-CAHS (50:50) mixture were credited to a robust pseudo-emulsion film formation, creating a higher oil entry barrier. This reinforcement and the surfactant molecules' synergistic interactions at the gas-liquid-oil interface significantly contributed to the overall effectiveness.

The effect of solution plasma treatment on the microbial safety and quality characteristics of albumen.

The aim of this study was to make eggs microbially safe and increase their durability without damaging the functional properties of the albumen and preserving the solubility of its proteins as much as possible by the solution plasma technique. The pH, Brix, density, and viscosity values of samples decreased during treatment (p < .05 except pH). Although the L* and a* values of both the albumen and egg foam decreased, the b*, hue angle, and chroma values of both increased during treatment. The L* and a* values of the albumen decreased by 7.01 and 1.89 units, and the values of the egg foam decreased by 10.93 and 1.03 units, respectively. At the end of the treatment, foaming capacity and foam stability were decreased by 25% and 21.42%, respectively. Foaming capacity values obtained as a result of this treatment were higher and foam stability values were lower compared to the values obtained in pasteurization of eggs by heat treatment. The count of the two pathogenic bacteria inoculated into the albumen decreased during the treatment (p < .05), the count of Salmonella Enteritidis decreased to 0, and the count of Staphylococcus aureus decreased by 1.09 log cfu/g at the end of the treatment. Compared to current heat treatments, solution plasma treatment caused significantly less adverse effects on albumen quality characteristics. In particular, the foaming properties of the albumen were much less affected by this method and remained at higher values compared to the values achieved by other methods. The treatment also produced a microbiologically safer product.

Oleo-foams and emulsion-foams as lipid-based foam systems: a review of their formulation, characterization, and applications.

Lipid-based foam systems (LBFs) have grown in popularity recently because of their effectiveness and potential uses. As a result, in order to stabilize them, considerable work has been put into developing more biodegradable and environmentally friendly materials. However, the use of natural stabilizing agents has been constrained due to a lack of thorough knowledge of them. This review offers insightful data that will encourage more studies into the development and use of LBFs. Emulsifiers or gelling agents, as well as new preparation and characterization methods, can be used to increase or prolong the functional performance of LBFs. Special emphasis has been given on the connections between their structures and properties and expanding the range of industries in which they can be applied. In conclusion, it is crucial to gain a deeper understanding of the preparation mechanisms and influencing factors in order to improve the quality of foam products and create novel LBFs.

Chemical-Physical Properties of Red Palm Oils and Their Application in the Manufacture of Aerated Emulsions with Improved Whipping Capabilities.

Red palm oil (RPO), which is rich in micronutrients, especially carotenoids, is different from its deodorized counterpart, palm oil. It is considered as one of the most promising food ingredients, owing to its unique compositions and nutritional values, while its usage could be further developed by improving its thermal behaviors. In this article, two typical commercial RPOs, HRPO (H. red palm oil) and NRPO (N. red palm oil), were evaluated by analyzing their fatty acids, triacylglycerols, micronutrients, oxidative stability index (OSI), and solid fat contents (SFCs). Micronutrients, mainly carotenes, tocopherols, polyphenols, and squalene, significantly increased the oxidative stability indices (OSIs) of the RPOs (from 10.02 to 12.06 h), while the OSIs of their micronutrient-free counterparts were only 1.12 to 1.82 h. HRPO exhibited a lower SFC than those of NRPO. RPOs softened at around 10 °C and completely melted near 20 °C. Although the softening problem may limit the usages of RPOs, that problem could be solved by incorporating RPOs with mango kernel fat (MKF). The binary blends containing 40% RPOs and 60% MKF exhibited desirable compatibilities, making that blend suitable for the manufacture of aerated emulsions with improved whipping performance and foam stabilities. The results provide a new application of RPOs and MKF in the manufacture of aerated emulsions with improved nutritional values and desired whipping capabilities.

Study on the Effect of Foam Stability on the Properties of Foamed Lightweight Soils.

The properties of prepared foamed lightweight soils (FLSs) using prefabricated foam requires high foam stability. This paper investigates the geometrical characteristics of different foam densities, different types of foaming agents in the air, and the presence of slurry. Then, it studies their effects on the pore structure and mechanical properties of FLS. Results show that with the increase in foam density the bleeding rate of foam in the air for 1 h increases and the foam with a foam density of 50 kg/m3 is the most stable in the air. The stability of foam in slurry is not directly related to the property of foam in the air. The FLS prepared with the same foaming agent had the best performance with the FLS designed with a foam density of 50 kg/m3, which had the smallest average pore size and the most minor pore size distribution, and had the highest compressive strength. Among the three different foaming agents, Type-S was the best, and the slurry had the lowest rate of increase in wet density after the defoaming test, indicating that the foam had the best stability in the cement slurry. The FLS prepared with the density of 50 kg/m3 using the Type-S foaming agent and mixed with the slurry of cement, fly ash:slag:water = 105:105:140:227.5, was hardened to a mean pore size of 299 µm, and the 7 days, 28 days, and 56 days compressive strengths were 0.92 MPa, 2.04 MPa, and 2.48 MPa, respectively, which had the smallest average pore size and the highest compressive strength among the FLSs prepared using the three foaming agents.

Oleofoams stabilized by monoacylglycerides: Impact of chain length and concentration.

Oleofoams are plant oil based whipped systems which have drawn academic and industry attention in recent years. The aim of this study was to determine the effect of fatty acid chain length and monoacylglyceride (MAG) concentration on the performance and structural properties of MAG-based oleofoams. Four different MAGs (monolaurin, monomyrystin, monopalmitin, and monostearin) were studied at three concentration levels (5, 10, and 15 wt%). The fatty acid chain length had a statistically significant impact on the size and shape of crystals formed, while higher MAG concentrations led to higher numbers of crystals in the continuous oil phase. These differences affected the performance and physical properties of the oleofoams: compared to other MAGs, monostearin based oleofoams were harder and exhibited higher values of G' and G″, had higher overrun and showed better stability. Lastly, through microscopy techniques it was successfully proved that monostearin-based oleofoams are stabilized by both bulk and Pickering stabilization.

On the mechanism of enhanced foam stability by combining carboxylated cellulose nanofiber with hydrocarbon and fluorocarbon surfactants.

The effect of carboxylated cellulose nanofiber (CCNF) on the firefighting foam stability and stabilization mechanism is investigated. The results show that equilibrium surface tension of CTAB/FC1157 solution decreases when CCNF concentration increases to 0.5 wt%, while CCNF has little effect on that of SDS/FC1157 solution. Besides, when CCNF concentration increases to 1.0 wt%, the foam initial drainage of SDS/FC1157 solution is delayed for about 3 min. Increasing CCNF concentration can slow down foam coarsening process and liquid drainage process of SDS/FC1157 and CTAB/FC1157 solutions, improving the foam stability. The foam stability enhancement of CTAB/FC1157-CCNF solution is due to the formation of bulk aggregates and the increase of viscosity. However, the foam stability enhancement of SDS/FC1157-CCNF solution may be caused by the increase of viscosity. CCNF significantly reduces the foaming ability of CTAB/FC1157 solution when CCNF concentration is >0.5 wt%. Nevertheless, the foaming ability of SDS/FC1157 solution decreases significantly when CCNF concentration reaches 3.0 wt%, and its foaming ability remains higher than CTAB/FC1157 solution. The foaming ability of SDS/FC1157-CCNF solution is mainly dominated by viscosity, while that of CTAB/FC1157-CCNF solution is dominated by viscosity and adsorption kinetics. Adding CCNF is expected to enhance the stability of firefighting foam and increase the efficiency of extinguishing fire.

Effect of shearing-induced lipolysis on foaming properties of milk.

BACKGROUND: The attraction of cappuccino-style beverages is attributed to the foam layer, as it greatly improves the texture, appearance, and taste of these products. Typical milk has a low concentration of free fatty acids (FFAs), but their concentration can increase due to lipolysis during processing and storage, which is detrimental to the foamability and foam stability of milk. There are contradictory results in reported studies concerning the effects of FFAs on the foaming properties of milk due to differences in milk sources, methods inducing lipolysis, and methods of creating foam. In this study, the foaming properties and foam structure of milk samples whose lipolysis was induced by ultra-turraxing, homogenisation, and microfluidisation (1.5-3.5 µ-equiv. mL-1 FFAs) were investigated. RESULTS: Compared with others, microfluidised milk samples had the smallest particle size, lowest absolute zeta potential, and highest surface tension; thus exhibited high foamability and foam stability, and very small and homogeneous air bubbles in foam structure. For all shearing methods, increasing FFA content from 1.5 to 3.5 µ-equiv. mL-1 markedly decreased the surface tension, foamability, and foam stability of milk samples. The FFA level that led to undesirable foam structure was 1.5 µ-equiv. mL-1 for ultra-turraxed milk samples and 2.5 µ-equiv. mL-1 for homogenised and microfluidised ones. CONCLUSION: Shearing-induced lipolysis greatly affected the physical properties of milk samples and subsequently their foaming properties and foam structure. At the same FFA level, lipolysis induced by microfluidisation was much less detrimental to the foaming properties of milk than lipolysis induced by ultra-turraxing and homogenisation. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The effect of barley to wheat ratio in malt blends on protein composition and physicochemical characteristics of wort and beer.

The present work explored the effect of barley to wheat ratio in malt blends on protein composition and physicochemical characteristics of wort and beer. Results illustrated that the addition of wheat malt can significantly improve the soluble protein of wort and the final beer, and it can provide more > 2.2 kDa protein in final beer, which is mainly derived from the raw wheat malt, but also including some protein produced in the fermentation process, such as some protein between 29 and 66.4 kDa. Though the content of > 15 kDa protein was relatively lower than the protein whose molecular weight was < 15 kDa, but it had important effects on total nitrogen, total water-soluble protein, free amino nitrogen, chromaticity, and viscosity of final beer. The addition of wheat malt significantly improved the concentration of 2.2-15 and > 15 kDa protein, but higher percentage of addition ratio can decrease the foam stability of the beer. PRACTICAL APPLICATION: This findings can reasonably control the protein content and types of wheat beer, improve the quality of wheat beer, solve the key technological problems, and expand and popularize the application of wheat in beer industry.

Study on the effect of nanoparticles combined with silicone surfactant and cationic surfactant on foam and fire extinguishing performance.

Aqueous film-forming foam (AFFF) in firefighting foam can effectively extinguish oil fire. However, AFFF will be phased out due to the presence of persistent organic pollutants such as perfluorooctane sulfonates. It is necessary to explore environment-friendly foam extinguishing agent. Silicone surfactant is a kind of environmentally friendly surfactants with high surface activity, which can be used as a substitute for fluorocarbon surfactant. In this study, silicone surfactant and cationic surfactant were combined to adsorb nanosilica particles to form a multiphase system. The foaming property and foam stability of the multiphase system were tested by stirring method. The foam suppression effect on fuel vapor, fire extinguishing, and burn-back performance was tested by self-designed foam suppression device and foam generating device of porous glass with recyclable liquid supply. The experimental results show that foam stability is enhanced and the foaming property is slightly decreased after the addition of nanoparticles. When the component of three-phase foam reaches the optimum, its suppression effect on fuel vapor is better than that of two-phase foam. The results of fire extinguishing and burn-back performance test showed that the fire extinguishing effect of three-phase foam was slightly worse than that of AFFF, but it has extremely strong burn-back performance.

The Influence of the Surface Chemistry of Cellulose Nanocrystals on Ethyl Lauroyl Arginate Foam Stability.

Guanidine-based surfactant ethyl lauroyl arginate (LAE) and cellulose nanocrystals (CNCs) form complexes of enhanced surface activity when compared to pure surfactants. The LAE-CNC mixtures show enhanced foaming properties. The dynamic thin-film balance technique (DTFB) was used to study the morphology, drainage and rupture of LAE-CNC thin liquid films under constant driving pressure. A total of three concentrations of surfactant and the corresponding mixtures of LAE with sulfated (sCNC) and carboxylated (cCNC) cellulose nanocrystals were studied. The sCNC and cCNC suspension with LAE formed thin films, with stability increasing with surfactant concentration and with complex rheological properties. In the presence of LAE, the aggregation of CNC was observed. While the sCNC aggregates were preferentially present in the film volume with a small fraction at the surface, the cCNC aggregates, due to their higher hydrophobicity, were preferentially located at film interfaces, forming compact layers. The presence of both types of aggregates decreased the stability of the thin liquid film compared to the one for the LAE solution with the same concentration. The addition of CNC to LAE was critical for foam formation, and foam stability was in qualitative agreement with the thin films' lifetimes. The foam volume increased with the LAE concentration. However, there was an optimum surfactant concentration to achieve stable foam. In particular, the very resistant foam was obtained with cCNC suspensions that formed the interfaces with a complex structure and rheology. On the other hand, at high LAE concentrations, the aggregates of CNC may exhibit antifoaming properties.

The Stabilizing Effect of Carboxymethyl Cellulose on Foamed Concrete.

Foam concrete is widely used for its excellent properties, such as light weight, heat insulation, fire resistance, and sound insulation. The stability of foam is the main factor that affects the mechanical performance of foam concrete. The experiments are designed from two perspectives: the foam's stability performance and the foam concrete's modification effect. The effects on foam volume, foam half-life, foam bleeding rate, and foam pore size were investigated based on different concentrations of foam stabilizer CMC (0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%). A combination of macroscopic testing and microscopic analysis, a comparative study of dry density, water absorption test, mechanical property test, and pore structure analysis were conducted after using the modified foam for foam concrete. It is shown that the addition of CMC has an enhanced effect on foam stability. Foaming volume, water secretion rate, and average pore size showed a decreasing trend with the increase of CMC admixture, while the foam half-life displayed an increasing trend. In addition, adding CMC reduces the dry density and improves water absorption and compressive strength. The pore structure development of foam concrete has a noticeable improvement effect, and the optimal amount of admixture is 0.4%. Research results provide a reference for applying thickening foam stabilizer CMC in foam concrete.

Study towards understanding foaming and foam stability in urban lakes.

Foaming water bodies have become a matter of great concern globally. Foam disrupts aquatic ecosystems, emits an offensive smell, disrupts the day-to-day activities in neighbouring localities, and is visually unpleasant. The downstream water bodies are also exposed to the risk of foaming. Even though widespread, the foaming phenomena of surface water bodies are not adequately studied. The present study focuses on the foaming Lake of Bellandur in South India - wherein the sources and concentration of surfactants, effect of phosphorous, effect of bacteria, and its synergy with surfactants were studied. The study revealed that the significant source of pollution in the Lake was the entry of untreated sewage, which consisted of surfactants. The anionic surfactant concentration in the Lake was 17 ± 3 ppm, and surface tension remained around 50 mN/m, similar to the treatment plant inlet. The Phosphorus concentration in the Lake was high at 10 ± 3 ppm, with the primary source being feces and urine. Phosphorus indirectly affected the surfactant concentration of the Lake. Foam stability studies showed that mixed bacteria (filamentous) from Bellandur, in its stationary phase-played a crucial role in adding to the stability of the foam. The highest contributing filamentous bacterial family was found to be Flavobacteriia.

Foam stability of temperature-resistant hydrophobic silica particles in porous media.

The world is rich in heavy oil resources, however, the recovery difficulty and cost are both higher than that of conventional crude oil. To date, the most common method of recovering heavy oil is steam flooding. However, once the steam breaks through the geological formation, gas channeling readily occurs, which leads to a rapid decrease of the steam drive efficiency. To improve the swept volume of steam in the geological formation, a series of hydrophobic silica particles for stabilizing foam was synthesized. This kind of particles used hydrophilic nano silica particles as reactant. Hydrophobic groups with cationic long carbon chains were grafted onto the surface of hydrophilic silica particles by synthetic silane quaternary ammonium salt. When the quantity of silane quaternary ammonium salt used in the modification reaction is different, the product had various degrees of wettability. The hydrophobic particles with the contact angle closest to 90° had the best foam stabilization effect on the betaine zwitterionic surfactant LAB. For LAB solution with mass fraction of 0.3%, the half-life of foam was extended into 160% when the mass fraction of particles was 0.5%. The higher the gas-liquid ratio, the better the plugging effect of foam agent with hydrophobic particles presented in porous media. The adsorption test of hydrophobic particles indicated that hydrophobic particles improved the stability of foam liquid membrane by improving the adsorption capacity of surfactant molecules. The thermal stability of hydrophobic silica particles exceeded 200°C, and the good foam stability made it a potential additive for foam oil displacement in high-temperature geological formation.

Homogenization improves foaming properties of insoluble pea proteins.

Foams are essential in many food applications and require surface-active ingredients such as proteins for formation and stabilization. We investigated the influence of high-pressure homogenization on foaming properties of insoluble pea protein dispersions (5% w/w) at pH 3 and 5. Unhomogenized insoluble pea protein dispersions did not foam at either pH 3 or 5, as they consisted of large insoluble pea protein aggregates with limited surface activity. At pH 3, the homogenized pea protein dispersions generated foams due to higher protein solubility and surface activity through disruption of large protein aggregates into smaller particles. The foam stability decreased with increasing homogenization pressure and number of cycles due to a reduction in continuous phase viscosity. At pH 5, the insoluble pea proteins foamed when the homogenization resulted in formation of aggregates made of smaller protein entities, which was the case for homogenization ≥ 100 MPa and three cycles. In general, the foam capacity (amount of formed foam) was higher at pH 3 due to improved protein solubility and surface activity that facilitated incorporation of air, while the foam stability (resistance against foam collapse) was better at pH 5 because of the presence of larger protein aggregates that formed thicker and more viscous films around the air bubbles benefitting retention of gas bubbles. Overall, homogenization improved the foaming properties of insoluble pea proteins at pH 3 and 5. Practical Application Insoluble pea protein dispersions formed foams at pH 3 and 5 after homogenization highlighting the potential of this processing step for the food industry. The improvement in functionality of plant-derived ingredients helps to increase their use for consumer goods, thereby supporting the transition to more sustainable food system.