Modulating the properties of myofibrillar proteins-stabilized high internal phase emulsions using chitosan for enhanced 3D-printed foods

Tentative exploration of the 3D printing performance of the mixed inks with egg white proteins and mycoprotein fibrous to improve the quality of mycoprotein alternatives

Mycoprotein (MYC) has unique mycelial properties that make it suitable for mimicking meat fibers. However, the irregular structure of mycelium creates challenges in achieving fiber alignment in meat alternatives. This study explored 3D printing technology to align MYC fibers by formulating inks with various proportions of egg white proteins (EWP) (4 %, 5 %, 6 %, 7 %) and assessing their printing performance. Results showed that extrusion-based 3D printing enabled MYC fiber alignment. The addition of EWP resulted in a nonlinear viscoelastic state in the mixed ink, and increased intra-ring strains to restrict the mobility of the moisture, likely due to hydrogen bonding between mycelial and EWP. Post-printing, the MYC-EWP matrix formed a more ordered mycelial structure. After heating, the 6 % EWP formulation exhibited improved water retention, hardness, chewiness, and other textural properties, making it comparable to beef. This study highlights the potential of 3D printing technology to enhance fiber formation in MYC-based meat alternatives.

High internal-phase Pickering emulsions constructed using myofibrillar proteins from large yellow croaker: Effect of glycerol

Exploring the emulsification of myofibrillar protein (MP) from large yellow croaker (Larimichthys crocea) could meet the demand for high-value development and utilization of fish proteins. Therefore, MPs as the emulsifier to form stable high internal-phase Pickering emulsions (HIPPEs) with the addition of glycerol and the effects of different glycerol addition ratios of HIPPEs were investigated. HIPPEs could be constructed by MPs with the glycerol addition at a ratio of 15 %-30 % (v/v) compared to those without the addition of glycerol. With the increase in glycerol ratios, the absolute value of Zeta potential increased and reached 22.57 ± 0.29 mV at the glycerol ratio of 30 %. All the HIPPEs stabilized by MPs with the addition of glycerol possessed storage stability. Besides, the centrifugal stability constant (Ke), backscattered light intensity and reflected light stability index confirmed that the addition of glycerol was beneficial for the formation of stable HIPPEs prepared by MPs. Additionally, HIPPEs stabilized by MPs with the addition of glycerol possessed small emulsion droplets and viscoelastic behavior. These findings could be helpful for the development and utilization of MPs of large yellow croaker in the food industry.

Impact of hydrophobically modified cellulose nanofiber on the stability of Pickering emulsion containing insect protein

BACKGROUND

Cellulose nanofiber (CNF) is an ideal Pickering emulsion stabilizer because of its high aspect ratio and flexibility. CNF was hydrophobically modified by dodecenyl succinic anhydride and used to stabilize the simulated food emulsion system containing insect protein. The prepared dodecenyl succinate nanofiber (D-CNFs) was characterized by contact angle and laser particle size analyzer. The stability of the emulsion system under different conditions was characterized by zeta potential and appearance observation. Lastly, in vitro digestion simulation experiments were carried out to investigate whether the addition of D-CNFs had an effect on the digestion and absorption of oil.

RESULTS

The modification process for dodecenyl succinic anhydride to CNFs was that the system temperature was 40 °C, the system pH value was 8.5 and the reaction time was 6 h. The water contact angle of the modified CNFs increased to 83.2 ± 0.9°. D-CNFs were introduced into the simulated food emulsion system containing insect protein. The increase in the concentration of D-CNFs in the aqueous phase promoted the stability of the simulated emulsion system. Increasing the ratio of insect protein was not conducive to the stability of the emulsion. The final fat digestibility of the emulsion with D-CNFs was lower than that of the emulsion without D-CNFs.

CONCLUSION

Overall, the analysis and characterization results show the potential of the modified CNF as a food simulant emulsion stabilizer containing insect protein, which can be used for the development of specific functional foods. © 2024 Society of Chemical Industry.

Structural modification of whey protein isolate via electrostatic complexation with Tremella polysaccharides and its effect on emulsion stability at pH 4.5

Emulsions play an important role in food systems by encapsulating and delivering active compounds, but maintaining their stability under various conditions can be challenging. This study explored how the concentrations of Tremella polysaccharides (TPs) (0-0.75 %) affects the structural of whey protein isolate (WPI) and the stability of their emulsions at pH 4.5. At this pH, electrostatic interactions between WPI and TPs exposed hydrophobic groups within the protein, increased β-sheet contents, and improved the hydrophilic-hydrophobic balance, which enhanced emulsifying performance. WPI-TPs complexes (WTS) showed a high emulsifying activity index (57.85 m2/g) and emulsion stability index (82.03 %). Compared to WPI-only emulsions, WTS emulsions had smaller particle sizes, lower Turbiscan Stability Index (TSI) values, and higher viscoelasticity, thermal stability, freeze-thaw stability, and re-emulsification capacity. Importantly, when the TPs concentration in WTS emulsions exceeded 0.375 %, the TSI value dropped below 1, showing no particle migration or peak thickness, indicating full emulsion stability. These findings suggest that TPs help stabilize WPI emulsions near their isoelectric point (pH 4.5) and offer a promising approach to improving WPI functionality in acidic environments. The WTS system provides a reliable way to stabilize emulsions under acidic conditions, supporting the development of natural, stable emulsifiers for food applications.

Low-internal-phase and high-viscoelastic emulsion gel synergistically stabilized by buckwheat protein microgel and carboxylated cellulose nanofibers

With the increasing demand for healthy diets, low-fat foods have gradually become a hot issue. This study successfully prepared low-internal-phase and high-viscoelastic emulsion gels using the synergistic effect between buckwheat protein microgel (BPM) and carboxylated cellulose nanofibers (CNF). The effects of the ratio of BPM to CNF on the microstructure, stability, rheological properties, and 3D printing characteristics of the emulsion gels were investigated. The results showed that the emulsion gels with good viscoelasticity could not be constructed when BPM or CNF alone was used as a stabilizer. The emulsion gels synergistically stabilized by BPM and CNF had a dense microstructure, good environmental stability, and rheological properties. When the ratio of BPM to CNF was 3:7, emulsion gels with different oil phase fractions (5 %, 10 %, 30 %, and 50 %) showed elasticity-dominated solid-like behavior and excellent environmental stability. The 3D printing results show that with the addition of CNF, the emulsion gel stabilized synergistically by BPM and CNF exhibits better extrusion and self-supporting behaviors, and all the print products can precisely replicate the preset models. Therefore, this study may provide new design ideas for constructing low-internal-phase and high-viscoelastic emulsions and their application in 3D-printed food.

Systematic free energy insights into the enhanced dispersibility of myofibrillar protein in low-salt solutions through ultrasound-assisted enzymatic deamidation

This work aimed to investigate the effects of ultrasound assisted enzymatic deamidation by protein-glutaminase (PG) on the dispersion of myofibrillar protein (MP) in low-salt solutions. The solubility, structural characteristics, transmission electron microscopy, asymmetric-flow field-flow fractionation, steady shear rheological property and multiple light scattering of MP deamidated by PG (MP-PG) and MP pretreated with ultrasound followed by PG deamidation (MP-U-PG) were determined. Molecular docking and molecular dynamics (MD) simulations were used to estimate the interaction between PG and MP. Under ultrasound assistance, the MP deamidated for 16 h (MP-U-PG16) showed the highest solubility (80.1 %) in low-salt conditions, which is attributed to its highest absolute zeta potential and smallest particle size. Although secondary structure analysis showed that MP-PG and MP-U-PG had an increased α-helix ratio and a decreased β-sheet ratio, ultrasonic treatment had a significantly influence on the MD results. The results manifested that hydrogen bond was the primary forces driving the binding between PG and MP, and the hydrogen bond and hydrophobic interaction were the dominant forces responsible the binding between PG and MP pretreated with ultrasound. According to the energy landscapes theory, ultrasound could overcome the energy barriers through external force input and find the best pathway to achieve the final lowest energy state. Our research contributed to the improvement of the colloidal dispersibility of MPs under low-salt conditions and the regulation of protein interaction by ultrasound assistance.

Preparation and characterization of lactoferrin-polyphenol conjugate with stabilizing effects on fish oil high internal phase Pickering emulsions

The combination of protein and polyphenol is an effective approach to improve the stability of protein emulsions. The lactoferrin (LF)-(-)-epigallocatechin-3-gallate (EGCG) covalent complex (LF-EGCG) was first prepared by alkali-induced reaction, then the structure and physicochemical properties between LF-EGCG and non-covalent complex (LF + EGCG) were compared, and finally the stability of complexes to fish oil high internal Pickering emulsions (HIPPEs) was tested. Results showed that LF-EGCG had stronger antioxidant activity, higher thermal stability, and better surface wettability than LF + EGCG. Meanwhile, the complexes showed no cytotoxicity within the tested concentration range (12.5-200 μg/mL). The HIPPEs stabilized with LF-EGCG possessed smaller droplet size, higher ζ-potential, and more uniform oil/water proton distribution. Covalent treatment also enhanced the storage, thermal, freeze-thaw and physical stability of LF HIPPEs. Furthermore, due to the higher antioxidant activity and denser microstructure, LF-EGCG HIPPE can more effectively inhibit the oxidation of fish oil.

Gliadin/Konjac glucomannan particle-stabilized Pickering emulsion for honokiol encapsulation with enhanced digestion benefits

Owing to the limited availability of biocompatible, edible and natural emulsifiers, the development of Pickering emulsions applicable to the food industry still confronts challenges. Moreover, Honokiol (HNK), due to its poor stability and susceptibility to oxidation, most of the existing delivery systems are centered on injection administration routes and relatively complex in preparation, posing significant challenges for industrialization. In this research, a Pickering emulsion system stabilized by gliadin and konjac glucomannan composite particles (GKPs) was constructed using the pH cycling method and was employed for the delivery of HNK. Under the conditions of a 1:2 mass ratio of the composite particles at pH 4 and an oil phase fraction of 50 %, the storage stability of HNK was effectively enhanced, attaining a retention rate of 84.88 % ± 0.78 % at 4 °C for 14 days. In simulated in vitro digestion, this emulsion system effectively mitigated the degradation of HNK, achieving a bioavailability of 66.94 % ± 4.05 % and increasing the release of free fatty acids. Pickering emulsions stabilized by GKPs may provide a useful means of delivery of bisphenol lignans.

Collaborative stabilizing effect of trehalose and myofibrillar protein on high internal phase emulsions: Improved freeze-thaw stability and 3D printability

This study investigated the improvement of adding trehalose (Tre) on freeze-thaw (F-T) stability and 3D printability of myofibrillar protein (MP)-based high internal phase emulsions (HIPEs), also the underlying mechanism. Appropriate Tre addition formed thicker shell-like structure around MP by hydrogen bonds, and induced protein unfolding to ameliorate amphiphilicity. Additionally, Tre promoted the MP diffusion to interface to reduce interfacial tension. After interface saturation, Tre inducing MP rearrangement contributed more to form compact interface layer. Larger interface coverage increased hydrophobic interactions between droplets, constructing stronger MP-Tre-HIPEs gel network, inhibiting more free water to form ice crystals, confirmed by reduced destabilization index and freezing point. Such gel network enhanced their own viscoelasticity and thixotropic recovery, exhibiting superior printing accuracy. Conversely, excessive Tre aggregates (15 %-20 %) competed with MP for interfacial adsorption and filled between interfacial layer of adjacent droplets, weakening gel network. These findings expanded MP-HIPEs high-value application in frozen-foods and 3D printing.

Relationship between the interfacial properties of lactoferrin-(-)-epigallocatechin-3-gallate covalent complex and the macroscopic properties of emulsions

This study explored the relationship between the interfacial behavior of lactoferrin-(-)-epigallocatechin-3-gallate covalent complex (LF-EGCG) and the stability of high internal phase Pickering emulsions (HIPPEs). The formation of covalent bond between lactoferrin and polyphenol was verified by the increase in molecular weight. In LF-EGCG group, the surface hydrophobicity, interfacial pressure, and adsorption rate were decreased, while the molecular flexibility, interfacial film viscoelasticity, and interfacial protein content were increased. Meanwhile, LF-EGCG HIPPE possessed reduced droplet size, increased ζ-potential and stability. Rheology showed the viscoelasticity, structural recovery and gel strength of LF-EGCG HIPPE were improved, giving HIPPE inks better 3D printing integrity and clarity. Moreover, the free fatty acids (FFA) release of LF-EGCG HIPPE (62.6%) was higher than that of the oil group (50.1%). Therefore, covalent treatment effectively improved the interfacial properties of protein particles and the stability of HIPPEs. The macroscopic properties of HIPPEs were positively regulated by the interfacial properties of protein particles. The result suggested that the stability of emulsions can be improved by regulating the interfacial properties of particles.

A novel route to 3D printable protein-based HIPEs developed with shiitake oil

Tuning protein-based Pickering high internal phase emulsions (HIPEs) into 3D printing inks is promising in the food fields. Currently, the correlation between the changes in oil phase composition and the regulation of protein-based HIPEs 3D printing performance is still unclear. In this study, spiking the shiitake oil (ranging from 0 to 60 %) into the soybean oil phase of HIPEs can enhance their rheological properties and induce the formation of 3D printable HIPEs. The rheological tests showed that the yield stress and viscosity of the HIPEs respectively increased from 81.8 ± 4.84 Pa to 309 ± 16.3 Pa and from 409-1.74 Pa.s to 1762-2.93 Pa.s with increasing the shiitake oil concentration (0 % to 60 %) in the oil phase. In this study, the spontaneous interaction between phenolic compounds in shiitake oil and interfacial casein promoted the aggregation of protein, which led to the formation of casein cross-linking network in emulsion droplets, thus realizing the self-supporting and printing fidelity required for 3D printing. These findings provide a new perspective for enhancing the 3D printing properties of protein-based HIPEs.

Soy protein isolate-sodium alginate colloidal particles for improving the stability of high internal phase Pickering emulsions: Effects of mass ratios

The potential of sodium alginate (SA) at different mass ratios to improve the emulsifying ability of soy protein isolate (SPI) in high internal phase Pickering emulsions (HIPPEs) was evaluated in this work. SPI-SA particles were used as a natural particle stabilizer of HIPPEs with 80 % oil phase. The properties of particles with varying SPI to SA ratios (10:0, 10:1, 10:3, 10:5, 10:10, and 10:15 w/w) were evaluated. HIPPEs with a 10:10 SPI to SA ratio exhibited the smallest droplet sizes. Both the storage modulus and loss modulus of the HIPPEs increased with increasing SA addition ratios, implying that HIPPEs with higher SA addition have stronger gel characteristics. In addition, super-resolution microscopy and cryogenic scanning electron microscopy indicated that SA addition strengthened the compactness of the interface film and increased the distribution uniformity of HIPPEs. In conclusion, the combination of SPI and SA is beneficial for improving the performance of HIPPEs.