Increased Surface Hydrophobicity Research Articles

Fungal Chitin Nanofibrils Improve Mechanical Performance and UV-Light Resistance in Carboxymethylcellulose and Polyvinylpyrrolidone Films.

Materials from renewable carbon feedstock can limit our dependence on fossil carbon and facilitate the transition from linear carbon-intensive economies to sustainable, circular economies. Chitin nanofibrils (ChNFs) isolated from white mushrooms offer remarkable environmental benefits over conventional crustacean-derived nanochitin. Herein, ChNFs are utilized to reinforce polymers of natural and fossil origin, carboxymethyl cellulose (CMC) and polyvinylpyrrolidone (PVP), respectively. Incorporation of 5 wt % ChNFs increases the Young's modulus from 1217 ± 11 to 1509 ± 22 MPa for PVP and from 1979 ± 48 to 2216 ± 102 MPa for CMC. ChNFs increase surface hydrophobicity and retard the scission of the C-H bond as a result of UV-light irradiation in both polymers under investigation. The yellowing from chain scission is reduced, while long-lasting retention of ductility is ensured. Given these results, we propose the utilization of ChNFs in sustainable polymeric materials from renewable carbon with competitive performance against fossil-based benchmark plastics.

High-intensity ultrasound modification of techno-functional and structural properties of white finger millet protein fractions.

In this study, albumin, globulin, and glutelin were extracted from white finger millet, and their amino acid content, functional and structural properties were investigated. The protein concentration of albumin, globulin, and glutelin were 76.01%, 74.32%, and 69.55%, respectively. The results showed that all the fractions had a significant amount of essential amino acids. Aqueous protein dispersions (10%, w/v) were treated for 12min at different ultrasound power levels (100, 200, and 300W). The solubility, emulsifying, and foaming properties of albumin and glutelin were significantly (p<0.05) improved after ultrasound treatment (20kHz) which indicates that ultrasound could unfold protein aggregates. A decrease in particle size, increase in surface hydrophobicity, and zeta potential correlated with improved functional properties. Ultrasound treatment reduced the size of all proteins except for fractions at 300W and also sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a significant change in the molecular weight of albumin and glutelin at 300W. Scanning electron microscopy of treated protein fraction showed distinctive microstructure with irregular structure compared to untreated protein fraction. Although Fourier transform infrared spectroscopy spectra of proteins were similar after ultrasonication, a partial increase in the intensity of the Amide A band was observed. In conclusion, the ultrasound-treated protein fraction can be used as a high-value plant-based emulsifier.

Effects of mono- and dual-frequency ultrasounds on structure and physicochemical properties of faba bean proteins

Faba bean proteins are currently viewed as promising animal protein alternatives. However, certain functional properties e.g. relatively low solubility compared to whey protein isolates, can limit the application of faba bean protein isolates (FPIs) in certain food products. Therefore, it may be desirable to use modification approaches such as the application of ultrasound to alter such limiting physicochemical properties. In this study, Faba Bean Protein Isolates (FPI) were treated by ultrasound with different frequencies (20 kHz, 40 kHz and 20 + 40 kHz) prior to hydration (1 %) at different pH levels (3, 7, and 9). Then the structure and physicochemical properties (i.e. particle size, ζ-potential, surface hydrophobicity, thermal behavior, and solubility) of control and untreated FPIs were investigated. Ultrasound treatment had no obvious effect on the molecular weight of FPIs, whereas it changed the secondary structure of FPIs from a more ordered structure to a more disordered structure. The applied treatment resulted in an increase in surface hydrophobicity across all treatment levels and pHs. It also decreased the particle size of FPI at pH 3, while it increased the particle size at pH 7 and 9, compared to the untreated FPI. In addition, the solubility and thermal properties of FPI were modified through the ultrasound treatment. The higher solubility of FPI could improve its potential to be used as a functional ingredient for many food applications. Ultrasound treatment at 20 kHz and 20 + 40 kHz had more effects on the physiochemical properties of FPI compared to that at 40 kHz. Overall, ultrasound treatment with different frequencies (20 kHz, 40 kHz, and 20 + 40 kHz) modified the structure and physiochemical properties of FPI to different degrees and may be beneficial for the development of FPI for certain food applications.

Improving the Gelation Properties of Pea Protein Isolates Using Psyllium Husk Powder: Insight into the Underlying Mechanism.

The industrial application of pea protein is limited due to its poor gelation properties. This study aimed to evaluate the effects of psyllium husk powder (PHP) on improving the rheological, textural, and structural properties of heat-induced pea protein isolate (PPI) gel. Scanning electron microscopy (SEM), intermolecular forces analysis, the quantification of the surface hydrophobicity and free amino groups, and Fourier transform infrared spectroscopy (FTIR) were conducted to reveal the inner structures of PPI-PHP composite gels, conformational changes, and molecular interactions during gelation, thereby clarifying the underlying mechanism. The results showed that moderate levels of PHP (0.5-2.0%) improved the textural properties, water holding capacity (WHC), whiteness, and viscoelasticity of PPI gel in a dose-dependent manner, with the WHC (92.60 ± 1.01%) and hardness (1.19 ± 0.02 N) peaking at 2.0%. PHP significantly increased surface hydrophobicity and enhanced hydrophobic interactions, hydrogen bonding, and electrostatic interactions in PPI-PHP composite gels. Moreover, the electrostatic repulsion between anionic PHP and negatively charged PPI in a neutral environment prevented the rapid and random aggregation of proteins, thereby promoting the formation of a well-organized gel network with more β-sheet structures. However, the self-aggregation of excessive PHP (3.0%) weakened molecular interactions and disrupted the continuity of protein networks, slightly reducing the gel strength. Overall, PHP emerged as an effective natural gel enhancer for the production of pea protein gel products. This study provides technical support for the development of innovative plant protein-based foods with strong gel properties and enriched dietary fiber content.

Encapsulation of resveratrol in nanosheet structured sodium caseinate dialdehyde β-cyclodextrin conjugate with enhanced physicochemical properties

The poor solubility and stability of resveratrol (Res) represent significant obstacles to its utilization and efficacy. Encapsulating in sodium caseinate (NaCas) has also faced issues concerning low encapsulation efficiency and stability. This study presented the synthesis of a novel NaCas and dialdehyde β-cyclodextrin (DA-β-CD) conjugate through the Schiff base reaction using a wet-heating method, which was then utilized to encapsulate resveratrol. Results showed the DA-β-CD was formed in the form of needle-like crystals, whereas the NaCas-DA-β-CD conjugate had a nanosheet structure. The NaCas-DA-β-CD exhibited a substantial increase in surface hydrophobicity, emulsifying activity index, and emulsion stability index. The incorporation of resveratrol into NaCas-DA-β-CD demonstrated a consistent and uniform dispersion at the nanoscale level. It achieved an encapsulation efficiency of 96.8% and exhibited excellent chemical stability, which surpasses those of the NaCas system. Furthermore, the water solubility and antioxidant capacity of resveratrol in NaCas-DA-β-CD exhibited characteristics similar to those in NaCas. The compacted nanosheet structure of the Res-NaCas-DA-β-CD complex, as observed in TEM and SEM, is likely responsible for those enhancements. Hence, the DA-β-CD can serve as an effective polysaccharide for protein modification, while the NaCas-DA-β-CD conjugate can function as an innovative delivery carrier for resveratrol and other hydrophobic bioactives.

Synthesis, structural characterization, thermal analysis and anticorrosion properties of novel AZO-based imidazo[1,2-a]pyridine derivatives: Experimental study and theoretical approaches

In this study, innovative AZO-based imidazo[1,2-a]pyridine derivatives were synthesized using simple and efficient synthetic approach enabling large-scale production. Thermal analysis highlights their suitability for potential applications requiring resistance to moderate temperatures. These compounds were investigated as corrosion inhibitors for MS in a 1 M HCl-medium. Corrosion inhibition studies, including weight loss, PotentioDynamic polarization and electrochemical impedance spectroscopy methods, revealed that AZOs exhibited maximum corrosion inhibition efficiencies reaching 96.13 % and 94.07 %, respectively, at a concentration of 10−3 M and a temperature of 298 K, with both compounds acting as mixed-type inhibitors. The study also delved into the influence of temperature and immersion time on inhibitory performance, revealing stable inhibition within the temperature range of 298–328 K. The calculated standard free energy of adsorption was −42.06 and −40.62 kJ/mol for AZO 1 and AZO 2, respectively, suggesting mixed-type adsorption, with adsorption behavior following the Langmuir isotherm. Morphological analysis through SEM and AFM, showed a reduction in surface roughness in the presence of the inhibitors, while water contact angle measurements indicated a significant increase in surface hydrophobicity. UV–visible and FT-IR analyses confirmed the interaction of AZOs with the MS surface, suggesting the formation of a protective layer composed of adsorbed AZO molecules. Furthermore, computational investigations employing DFT, Monte Carlo, and Molecular Dynamic simulation revealed the formation of coordinate bonds between the studied inhibitors and the metal surface, confirming adsorption on the metallic surface. These findings align well with experimental outcomes, and a possible corrosion inhibition mechanism process was discussed.

Spray dried protein concentrates from white button and oyster mushrooms produced by ultrasound-assisted alkaline extraction and isoelectric precipitation.

In the present study, the optimization of ultrasound-assisted alkaline extraction (UAAE) and isoelectric precipitation (IEP) was applied to white button (WBM) and oyster (OYM) mushroom flours to produce functional spray dried mushroom protein concentrates. Solid-to-liquid ratio (5-15% w/v), ultrasound power (0-900 W) and type of acid [HCl or acetic acid (AcOH)] were evaluated for their effect on the extraction and protein yields from mushroom flours submitted to UAAE-IEP protein extraction. Prioritized conditions with maximized protein yield (5% w/v, 900 W, AcOH, for WBM; 5% w/v, 900 W, HCl for OYM) were used to produce spray dried protein concentrates from white button (WBM-PC) and oyster (OYM-PC) mushrooms with high solids recovery (62.3-65.8%). WBM-PC and OYM-PC had high protein content (5.19-5.81 g kg-1), in addition to remarkable foaming capacity (82.5-235.0%) and foam stability (7.0-162.5%), as well as antioxidant phenolics. Highly pH-dependent behavior was observed for solubility (> 90%, at pH 10) and emulsifying properties (emulsification activity index: > 50 m2 g-1, emulsion stability index: > 65%, at pH 10). UAAE-IEP followed by spray drying increased surface hydrophobicity and free sulfhydryl groups by up to 196.5% and 117.5%, respectively, which improved oil holding capacity (359.9-421.0%) and least gelation concentration (6.0-8.0%) of spray dried mushroom protein concentrates. Overall, the present study showed that optimized UAAE-IEP coupled with spray drying is an efficient strategy to produce novel mushroom protein concentrates with enhanced functional attributes for multiple food applications. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of different thermal processing methods and thermal core temperatures on the protein structure and in vitro digestive characteristics of beef

This study aimed to investigate the effect of different thermal processing treatments on the protein digestion characteristics of beef. The beef samples were subjected to different cooking methods, namely steaming, boiling, and roasting, and different core temperatures (75 °C, 80 °C, 85 °C, and 90 °C), and were subjected to in vitro gastrointestinal digestion simulation. All the thermal processing treatments increased the protein digestibility; the samples that were steamed at 85 °C (S85), boiled at 80 °C (B80), and roasted at 80 °C (R80) showed the biggest gains. The S85 released more peptide species after gastrointestinal digestion, according to peptididomic studies. These differences were closely related to protein structure. Thermal processing treatments resulted in a higher degree of proteolysis and looser protein conformation, as evidenced by decreased intrinsic fluorescence and electrophoretic band intensity, increased surface hydrophobicity, and the change in protein secondary structure from α-helix to β-sheet and random coil. Based on the results, S85 was identified as the optimal thermal processing treatment for enhancing the digestibility of beef protein. The results provide valuable insights into the nutritional qualities and digestion of heat-processed beef protein.

A novel energy-saving and emission-reduction strategy based on facile preparation of thermal insulation coatings doped with modified vacuum ceramic microbeads for concrete protection

The development of thermal insulation protective coatings suitable for constructions and buildings offers a multifaceted approach: it substantially reduces indoor temperatures, enhances residential comfort, decreases air conditioning energy consumption, and conserves energy. Additionally, these coatings provide robust resistance against corrosive substances, thereby significantly prolonging the service life of concrete. In this work, the modification of vacuum ceramic microbeads (VCM) through the polymerization of catechol and hexamethylene diamine to form poly(catecholamine) (PCA) was investigated by FT-IR, XRD, and TEM analysis. Increased levels of incorporation of VCM@PCA further decreased thermal conductivity and increased surface hydrophobicity, while excessive incorporation detrimentally affected the coating's mechanical properties. PDMS/VCM@PCA coating demonstrated exceptional thermal insulation performance, reducing coating temperature by 15.9 °C under simulated sunlight exposure, and in outdoor experiments, the interior temperature of the simulated house with this coating was 4.2 °C lower than the external temperature, highlighting its potential for energy conservation, emission reduction, and building temperature regulation. Additionally, PDMS/VCM@PCA coating provided excellent protection for concrete structures, significantly enhancing abrasion resistance. It also improved the interfacial adhesion between the organic layer and concrete under dry, wet, and 10% NaCl immersion conditions. The addition of VCM@PCA further enhanced resistance to chloride ion penetration, effectively reducing chloride ingress. This thermal insulation protective coating presents a novel strategy for energy conservation, emission reduction, and sustainable development in the civil construction industry.

Ultrasound and high-speed shear pretreatments of walnut meal protein: Structural and functional characterization and mechanistic investigation

The study aims to investigate the effect of the addition of ultrasound (US) with high-speed shear (HSS) at the extraction stage on the yield, physicochemical, structural, and functional properties of walnut meal protein (WMP). Compared with the conventional alkaline soluble acid precipitation method, the WMP yields after US and HSS pretreatments were increased by 1.11 and 1.21 times, respectively. Protein samples treated with the US showed increased surface hydrophobicity, a more uniform distribution of particle sizes, and greater contact angles. SDS-PAGE results showed that the protein had broken peptide bonds at higher molecular weights. The proteins' free sulfhydryl groups and fluorescence intensity have both increased as a result of the two pretreatment approaches, indicating a substantial alteration in the proteins' tertiary structure. Dynamic light scattering and SEM findings revealed that the US and HSS treatments improved the protein water solubility and emulsion stability by reducing the aggregate particle size and homogenizing the protein dispersion system. These results indicate that US and HSS pretreatment can effectively solubilize WMP polymers and enhance the structural function of the protein. This provides a theoretical basis for the application of WMP in food processing and offers a suitable technology for improving protein utilization.

The effect of whey/soy protein fibril systems on the properties of fish gelatin stabilized emulsion gels

In this study, we investigated the effects of whey protein isolate fibril systems (WPF) and soy protein isolate fibril systems (SPF) combined with fish gelatin (FG) on the formation of emulsion gels. The aim was to evaluate how the origin and concentration of these fibril systems influence the structural, interfacial, and rheological properties of FG-stabilized emulsion gels, as well as their impact on creaming stability. FG was mixed with varying concentrations (0–2%) of WPF and SPF at pH 7, forming electrostatic complexes due to the opposite charge interactions between FG and the protein fibril dispersions. The results revealed that adding WPF and SPF increased surface hydrophobicity and enhanced interfacial activity. Increasing WPF concentrations led to a gradual decrease in emulsion droplet size owing to the increased absorbed protein content at the interface. Additionally, there was a significant improvement in the storage modulus of the emulsion gels. Conversely, introducing a small amount (0.1%) of SPF to FG increased the particle size, suggesting potential coalescence, but further increases in SPF concentration considerably reduced the particle size. Furthermore, SPF enhanced the viscoelasticity at lower concentrations, possibly due to a more uniform distribution within the continuous phase. However, excess SPF reduced the storage modulus of the emulsion gels. Our study provides valuable theoretical insights for the application of protein fibril systems in emulsion gel systems.

Investigating the different effects of soybean proteins and peptides on the adhesion capacity of Limosilactobacillus reuteri LR08 and Escherichia coli JCM1649

Soybean proteins and peptides cooperated Limosilactobacillus reuteri (L. reuteri) in various ways to inhibit Escherichia coli (E. coli), but their impact on adhesion to intestinal cells remains unclear. This study investigated the adhesion properties of L. reuteri LR08 and E. coli JCM1649 regulated by soybean proteins and peptides. Digested soybean proteins (dpro) significantly enhanced L. reuteri adhesion and increased surface hydrophobicity more effectively than digested peptides (dpep) during early logarithmic growth. Dpro also improved L. reuteri biofilm formation and auto-aggregation in the stationary phase. Conversely, dpep markedly reduced E. coli adhesion to HT-29 cells, diminishing its biofilm formation and surface properties. The inhibitory effect of dpro on E. coli adhesion was weaker than that of dpep. These results highlight the diverse modulation of L. reuteri and E. coli adhesion by dpep and dpro, providing a theoretical basis for the use of probiotics to alleviate foodborne intestinal infections.

Chitosan/gelatin coating loaded with ginger essential oil/β-cyclodextrin inclusion complex on quality and shelf life of blueberries

Blueberries are highly susceptible to fungal pathogens and oxidative deterioration due to their thin epidermal layer, which can be mitigated by applying a natural polymer-based antimicrobial coating to their surface. This study aimed to develop a chitosan/gelatin-based antimicrobial coating utilizing ginger essential oil (GEO) to extend the postharvest quality of blueberries. To ensure GEO's stability within the coating, it was initially encapsulated with β-cyclodextrin (β-CD) using the inclusion complexation technique. The GEO/β-CD inclusion complex (IC) formed rhomboidal shapes with high encapsulation efficiency and small particle sizes. When the optimized GEO/β-CD IC was incorporated into the chitosan/gelatin polymer solution, it significantly increased surface hydrophobicity and free radical scavenging activity, and suppressed the growth of three selected fungi, namely Botrytis cinerea, Penicillium italicum and Alternaria alternaria. The results of postharvest storage quality revealed that blueberry samples coated with CH/Gel-GEO/β-CD IC-5 effectively maintained the quality of blueberries by decreasing weight loss and decay incidence, and regulating anthocyanin and other oxidation-related enzyme activities compared to the control group during 16 days at 25 °C and 40 days at 4 °C storages. In conclusion, it can be stated that CH/Gel-GEO/β-CD composite coating can be a promising technology to address the drawbacks of blueberry preservation.

Irradiation-induced modifications of apple seed protein isolate: Exploring techno-functional, structural, thermal, and morphological characteristics

Waste valorization of apple seeds for protein extraction is a sustainable approach to the management of apple seed waste in the apple processing industry. The purpose of the research is to study the modification of apple seed protein isolates under different doses of irradiation on functional, structural, thermal, and morphological characteristics. Different irradiation doses of 8, 15, 20 25, and 50 kGy showed significant variations in protein content (88.70%–86.45%), total phenolic content (774.13–285.42 mg GAE/100g), and color profile of the apple seed protein. Irradiation altered the apple seed protein isolates' functional properties with increased foaming properties and emulsifying properties and decreased water and oil absorption properties. Irradiation induces denaturation and cross-linking in the apple seed protein structures, which increase surface hydrophobicity (708.66–1740.66), decreased zeta potential (−18.60 to −39.39 mV), and alteration in protein secondary structures with decreased α-helix (11.52–10.43 %), β-sheet content (60.82–60.13%), and random coils (16.82–16.19%), and increased β turns (10.79–13.22 %). DSC and TGA analysis revealed improved thermal properties using irradiation doses of 8–20 kGy whereas reduction for 25–50 kGy in irradiated apple seed proteins. Scanning electronic microscopy showed pores and aggregated structures of irradiated apple seed protein isolates. The study revealed the potential of irradiation as one of the non-thermal techniques for modifying apple seed protein isolates for protein valorization in various food applications.

Mechanisms of the structures and antioxidant activity of broad bean protein affected by AC electric field: changes in conformation and molecular interaction

SummaryThe hierarchical structure modification and antioxidant traits of broad bean protein (BBP) with low denaturation induced by alternating current electric field (ACEF) were examined. The ultraviolet, Fourier transform infrared, and Raman spectrometry showed that ACEF affected the tertiary and secondary structures of BBP, as evidenced by the significant increase in surface hydrophobicity, more β‐turns and random coils, fewer β‐sheets, and the variation of microenvironments of certain amino acid residues. X‐ray diffractometry revealed that ACEF reduced the relative crystallinity and granular size of BBP, increased lattice spacing, caused the weakening of intermolecular forces, and significantly decreased the compactness of spatial conformations in BBP. Furthermore, the antioxidant capacity of BBP increased following ACEF treatment and was influenced by voltage. This may be due to the BBP structure unfolding and the release of aromatic amino acids.

Impact of pH on the structure, interfacial and foaming properties of pea protein isolate: Investigation of the structure – Function relationship

This study explored the relationship between pea protein foaming properties and their structure and physicochemical properties under neutral and acidic pH. Results showed that pH modified the zeta potential, particle size and surface tension due to electrostatic changes. FT-MIR and fluorescence spectra revealed pH-induced conformational changes, exposing hydrophobic groups and increasing sulfhydryl content, promoting protein aggregation. At pH 3, the highest foaming capacity (1.273) and lowest foam expansion (6.967) were observed, associated with increased surface hydrophobicity and net charges, ideal for creating light foams with high liquid incorporation for acidic beverages or fruit-based mousses. Pea protein isolate generated stable foams with foam volume stability between 86.662 % and 94.255 %. Although neutral pH conditions showed the highest foam volume stability, their air bubbles increased in size and transitioned from spherical to polyhedral shape, suitable for visual-centric applications, like cappuccino foam and beer-head retention. Foams at pH 5 exhibited the smallest bubbles and maintained their spherical shape, enhancing drainage resistance, beneficial for whipped toppings. Strong correlations (Pearson correlation coefficient higher than 0.600) were noted between the structure, surface and foaming properties, providing crucial insights into optimizing pea protein functionality across various pH conditions, enabling the development of plant-based foamed products with tailored properties.

A natural protein-lipid co-assembly as efficient Pickering emulsifier from egg yolk sphere microgel prepared via high-pressure homogenization

Egg yolk sphere is a kind of natural colloidal histological structure formed by the co-assembly of a large number of proteins and lipids, which has the dual functions of hydrophilic and lipophilic for application in emulsion. In this study, egg yolk sphere microgels (EYSMs) were prepared by high pressure homogenization (HPH) technique at various pressures (0–90 MPa) and used as Pickering emulsifiers for emulsification to obtain oil-in-water emulsions with an oil-water ratio of 11:9. The microscopic morphology, structure, and physicochemical properties of EYSMs were analyzed. The results showed that EYSMs obtained at 60 MPa (60-EYSMs) exhibited superior emulsifying properties with an emulsifying activity index (EAI) of 2.8 m2/g and an emulsifying stability index (ESI) of 356.6 min, resulting in enhanced storage stability of the emulsion for 30 d. The HPH treatment decreased the lipid content in EYSMs while creating a more homogeneous protein-lipid arrangement, which provided EYSMs with balanced hydrophilic and hydrophobic sites to improve emulsifying properties. Furthermore, the free sulfhydryl groups and hydrophobic moieties exposed by HPH promoted -S-S- formation on the EYSMs surface, promoting the increase in surface hydrophobicity and emulsifying ability. The confocal laser scanning microscopy (CLSM) and cryogenic scanning electron microscopy (cryo-SEM) revealed that the EYSMs adsorbed at oil-water interface and formed an intercross-linked spatial three-dimensional network structure, which worked as a physical barrier to the stable emulsion formation. This study introduces a novel research concept and delves into the emulsification mechanism of protein-lipid composite particles, offering a fresh insight for the development and utilization of emulsifiers.

Solid-liquid interfacial nanobubble nucleation dynamics influenced by surface hydrophobicity and gas oversaturation

Over the past two decades, extensive research efforts have been devoted to exploring the existence, stability, and applications of interfacial nanobubbles (INBs). However, investigations into the microscopic nucleation process of INBs have been relatively limited. In this study, we utilized molecular dynamics simulations to elucidate the nucleation dynamics of INBs, with a particular focus on examining the influence of surface hydrophobicity and gas oversaturation. Our findings revealed a distinct preference for INBs to form on hydrophobic surfaces compared to hydrophilic ones, which agrees well with the experimental results. Temporal evolution analysis of the interfacial density of gas and liquid near the solid–liquid interface indicated a gradual enrichment of gas molecules at the hydrophobic surface, accompanied by a gradual disruption of the hydration layer, phenomena not observed on hydrophilic surfaces. The affinity of gas molecules towards the hydrophobic surface was further confirmed by potential of mean force (PMF) analysis, which demonstrated a decrease in the energy barrier and an increase in the potential well with increasing surface hydrophobicity. Moreover, increasing bulk gas supersaturation and surface hydrophobicity both contribute to shortening the INB nucleation time, primarily due to the enhanced gas enrichment rate. Further studies indicated that the gas enrichment rate had a directly proportional linear relationship with the bulk gas concentration. However, as the surface hydrophobicity increased, the gas enrichment rate initially rose rapidly and then entered a plateau phase. This may be because, when surface hydrophobicity is strong, the gas enrichment rate becomes limited by the diffusion of gas molecules in the liquid. These findings offer valuable insights into the nucleation mechanism of INBs on hydrophobic surfaces under gas oversaturation, contributing to a deeper understanding of their behavior and potential applications.

Molecular investigation of soybean protein for improving the stability of quinoa (Chenopodium quinoa willd.) milk substitute

Soybean could greatly improve stability of quinoa milk substitute. However, the key compound and underlying mechanisms remained unclear. Here we showed that soybean protein was the key component for improving quinoa milk substitute stability but not oil or okara. Supplementary level of soybean protein at 0%, 2%, 4%, and 8% of quinoa (w/w) was optimized. Median level at 4% could effectively enhance physical stability, reduce particle size, narrow down particle size distribution, and decrease apparent viscosity of quinoa milk substitute. Microscopic observation further confirmed that soybean protein could prevent phase separation. Besides, soybean protein showed increased surface hydrophobicity. Molecular docking simulated that soybean protein but not quinoa protein, could provide over 10 anchoring points for the most abundant quinoa vanillic acid, through hydrogen bond and Van-der-Waals. These results contribute to improve stability of quinoa based milk substitute, and provide theoretical basis for the interaction of quinoa phenolics and soybean protein.

Antioxidant amyloid fibril derived from rice protein hydrolysate as stabilizer towards preparing high-stable emulsion

An antioxidant amyloid fibril was prepared as an emulsifier by fibrillating limited enzymatic hydrolysis-modified rice protein (HRP). The purpose of this study was to investigate the feasibility of using fibrillated HRP to stabilize oil-in-water emulsion. A free radical scavenging assay revealed that the antioxidant activity of fibrillated HRP was 2.09 times higher than that of native rice protein. Fibrillated HRP demonstrated a marked reduction in interfacial tension, increased surface hydrophobicity and contact angle (> 80°), and rapid adsorption to the interface, with 35.34 ± 2.43% interfacial adsorbed protein content. The fibrillated HRP barriers resisted environment stresses such as NaCl, pH variations, long-term storage, while reducing lipid oxidation degree. Additionally, fibrillated HRP-based emulsion was more effective in protecting β-carotene from degradation compared to other samples. These findings provide theoretical support for the development of rice protein-based antioxidant emulsifiers and modification of emulsifying properties of plant proteins.