Plant protein–polyphenol conjugates as antioxidant pickering emulsifiers: Ultrasonication-assisted stabilization of shrimp oil

The incorporation of faba bean flour (FBF) and protein isolate (FBI) into wheat-triticale flour blends is a potential promising strategy to enhance the nutritional and functional properties of bread. This study aimed to investigate the potential of these ingredients from both technological and sensory perspectives. Multiple analyses were conducted, including chemical composition, texture profile analysis, colour, specific volume and sensory properties of breads made with a blend of wheat and triticale flours (70:30). Part of the blend was substituted with either 20% faba bean flour or 7.2% faba bean protein isolate to ensure an equal proportion of faba bean protein in the final formulations. The results showed a significant increase in protein content for both FBF and FBPI breads, with the faba bean protein isolate also increasing the ash content. Texture profile analysis (TPA) indicated that the substitutions affected bread properties by increasing hardness, gumminess, and chewiness, particularly in bread with FBI. However, cohesiveness, springiness, and resilience decreased similarly in both cases. Additionally, the specific volume decreased with the addition of faba bean flour and protein, especially in FBI bread. From the colour aspect, analysis revealed a darker hue and a more pronounced reddish nuance in the bread crust in FBF and FBI breads. Sensory evaluation indicated a slightly lower overall likeability with faba bean addition, yet the breads remained acceptable to the panellists. Detailed sensory analysis supported the TPA findings and colour differentiation, showing higher values for hardness, crust compactness, and crumbliness. Texture and colour were rated lower compared to the control sample. Moreover, both FBF and FBI breads exhibited higher overall odour intensity. Specifically, bread with the protein isolate had less uniform pores and a more pronounced flour/cereal/bran odour. In contrast, bread with faba bean flour had more uniform pores but a noticeable bitterness. In conclusion, this study demonstrates that faba bean flour and protein isolate can be used as partial substitutes in wheat-triticale flour blends to produce bread with acceptable properties. This leaves room for future in-depth analysis and modifications to address the identified challenges.

Effects of drying techniques on the physicochemical, functional, thermal, structural and rheological properties of mung bean (Vigna radiata) protein isolate powder

This study investigated ultrasonication time dependent restructuring of heat-treated legume proteins, focusing on how sequential heat and ultrasound (HU) treatments influence the interfacial adsorption and stabilization of faba bean protein isolates (FBPIs) and pea protein isolates (PPIs) in high internal phase Pickering emulsions (HIPPEs). Proteins were first modified by heat treatment (90°C, 2h) and subsequently subjected to ultrasonication (20kHz, 120W, 5-20min). The resulting samples were characterized in terms of particle size, solubility, turbidity, surface charge, and secondary structure. HU treatment significantly reduced protein aggregation and particle size from 16.44μm (FCON) to 191.20nm (FHU20) for FBPI, and from 48.25μm (PCON) to 279.27nm (PHU20) for PPI, while solubility increased from 59.29% to 89.42% in FBPIs and 38.16% to 79.85% in PPIs. Moderate sonication durations (5-10min) yielded the smallest particles, highest solubility, and most flexible secondary structures, enabling cohesive and elastic interfacial films. By contrast, prolonged sonication (20min) led to partial reaggregation, weakening interfacial efficiency. HIPPEs stabilized by untreated proteins exhibited larger, heterogeneous droplets, whereas those stabilized by HU-treated proteins exhibited smaller, uniform droplet distributions. Despite the reduced adsorbed protein at interface (AP) and interfacial protein concentration (Γ), CLSM and TEM images confirmed continuous and uniform interfacial layers by the HU-treated proteins, contributing to improved emulsion stability. Rheological analysis further demonstrated the enhanced gel-like structure and viscoelasticity. Overall, the study highlights ultrasonication duration as a critical variable in HU treatment, dictating colloidal restructuring and interfacial adsorption behavior, and underscoring the suitability of legume proteins as clean-label stabilizers for high-oil emulsion systems.

Shrimp oil (SO) rich in n-3 fatty acids and astaxanthin, mixed with antioxidant-rich tea seed oil (TSO), was microencapsulated using mung bean protein isolate and sodium alginate and fortified into whole wheat crackers. SO and TSO mixed in equal proportions were emulsified in a solution containing mung bean protein isolate (MBPI) and sodium alginate (SA) at varied ratios. The emulsions were spray-dried to entrap SO-TSO in MBPI-SA microcapsules. MBPI-SA microcapsules loaded with SO-TSO showed low to moderately high encapsulation efficiencies (EE) of 32.26–72.09% and had a fair flowability index. Two selected microcapsules with high EE possessed the particle sizes of 1.592 and 1.796 µm with moderate PDI of 0.372 and 0.403, respectively. Zeta potential values were −54.81 mV and −53.41 mV. Scanning electron microscopic (SEM) images indicated that microcapsules were spherical in shape with some shrinkage on the surface and aggregation took place to some extent. Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) analyses of samples empirically validated the presence of SO-TSO in the microcapsules. Encapsulated SO-TSO showed superior oxidative stability and retention of polyunsaturated fatty acids (PUFAs) to unencapsulated counterparts during storage of 6 weeks. When SO-TSO microcapsules were fortified in whole wheat crackers at varying levels (0–10%), the crackers showed sensorial acceptability with no perceivable fishy odor. Thus, microencapsulation of SO-TSO using MBPI-SA as wall materials could be used as an alternative carrier system, in which microcapsules loaded with PUFAs could be fortified in a wide range of foods.

This study investigated how different ways of assembling of faba bean protein isolate (FBPI) and chitosan (CH) affected the oil-in-water emulsion stability. Emulsions were prepared either by a soluble FBPI-CH complex to make EMC, or by FBPI first and then added non-interactive CH to make EMN, or by FBPI first and then added a secondary layer of CH via electrostatic attraction to make EML. A control emulsion EMFB was prepared by only FBPI. All emulsions contained 5% (w/v) oil and 0.5% (w/v) FBPI. EMC/EML/EMN contained 0.05% (w/v) CH. The emulsion stability was monitored at 37 °C for 7 days. EML not only showed better physical stability as indicated by the changes in droplet size, Turbiscan stability index, and microstructure (by confocal microscopy), but also exhibited superior oxidative stability as indicated by lipid oxidation products (less conjugated dienes and secondary oxidation products) and protein oxidation biomarkers (less tryptophan loss and carbonyls formation). This might be attributed to that CH enhanced formation of a layer-by-layer (LBL) interfacial structure, which increased the interfacial layer thickness/compactness and maintained the interfacial protein adsorption. In contrast, EMC demonstrated worse stability, albeit with thicker interfacial layer due to CH. This could be explained by the lower surface hydrophobicity and surface charge of soluble FBPI-CH complex. The free aqueous CH also impaired physical stability and promoted oxidation, as shown in EMN. In conclusion, CH improves the oxidative and physical stability of FBPI-containing emulsion when added as a LBL model.

Impact of thermosonication at neutral pH on the structural characteristics of faba bean protein isolate dispersions and their physicochemical and techno-functional properties

ABSTRACTThe objective of this study was to determine the functional and structural properties of Maillard reaction products of mung bean [Vigna radiate (L.)] protein isolate with dextran obtained under the temperature of 80°C or 90°C with different times (0, 1, 2, 3, 4, 5, and 6 h). The mung bean protein isolate–dextran conjugate had better solubility, emulsifying activity, and emulsifying stability than mung bean protein isolate; however, the protein aggregation decreased the solubility, surface hydrophobicity, emulsifying activity, and emulsifying stability of mung bean protein isolate–dextran conjugate. In general, these functional properties of mung bean protein isolate–dextran conjugate obtained at 80°C with lower degree of glycosylation and browning degree were better than mung bean protein isolate–dextran conjugate obtained at 90°C. Both vicilin (8S) and legumin type (11S) globulins both participated in the graft reaction, the subunit with a molecular weight of 21 kDa that contributed to 11S globulin might be the most vulnerable to dextran followed by the 60, 32, and 26 kDa subunits. Maillard reaction between mung bean protein isolate and dextran led to a decreased fluorescence intensity and a bathochromic shift. The fluorescence intensity of mung bean protein isolate–dextran conjugate generally decreased, and λmax of mung bean protein isolate–dextran conjugate first increased and then decreased. The grafted mung bean protein isolates had lower α-helix content but higher β-sheet content. As the Maillard reaction between mung bean protein isolate and dextran proceeded, the α-helix contents of the mung bean protein isolate–dextran conjugates were significantly increased and then decreased, and the β-sheet content generally decreased and then increased. Excessive grafted dextran and more protein aggregation was observed in mung bean protein isolate–dextran conjugate obtained at 90°C, which induced structural changes that might have impaired the functions. Our findings suggest that conjugation of mung bean protein isolate with dextran through the Maillard reaction is an effective way of improving the functional properties of mung bean protein isolate for its application in the food industry.

Duck egg albumen hydrolysate-epigallocatechin gallate conjugates: Antioxidant, emulsifying properties and their use in fish oil emulsion

Influence of dietary inclusion of a wet processed faba bean protein isolate on post-smolt Atlantic salmon (Salmo salar)

Plant-based meat alternatives often require fat replacers to mimic the texture of traditional products. This study aimed to develop plant-based emulsion gels using mung bean protein isolate (MBPI) as a potential fat substitute. However, creating these gels via heat setting requires a high protein concentration, which demands modification of the MBPI structure to enhance emulsifying properties. This study investigated synergistic effects of alkaline treatment (0.3 or 3.5% Na2CO3) and heat treatments (40 or 70 °C) on the functional properties of MBPI at high protein levels, for potential application as a plant-based emulsion. The combined treatments reduced the zeta potential of protein suspensions from −9 to −19 mV and altered the protein conformation to form smaller particles (from 426 to 166 μm) with increased β-sheet content. These treatments improved dispersibility of 8% MBPI suspension (58 to 86%), emulsifying activity index (6.34–10.89 m2 g−1), and stability coefficient (43 to 96%). Notably, MBPI samples treated with 0.3% Na2CO3 at 40 and 70 °C exhibited excellent emulsifying properties, forming stable monolayers at the oil–water interface, likely due to the increased surface activity of MBPI. Increasing protein concentration to 11% facilitated heat-set gel formation; however, addition of 3.5%-Na2CO3 induced premature gelation, limiting its application in emulsions. At 0.3%-Na2CO3, increasing the protein content from 8% to 11% and the oil content from 10% to 30% further reduced emulsion droplet size, especially for MBPI treated with 0.3% Na2CO3 at 70 °C (MB-0.3%-70 °C) from 5.10 to 2.61 μm, likely due to decreased coalescence. This treatment yielded superior MBPI-stabilised emulsion gels with enhanced penetration, fluid retention, and stability by possibly reducing protein aggregation. These findings demonstrate the potential of MBPI modified by combined addition of 0.3% Na2CO3 and heat treatment, particularly MB-0.3%-70 °C, as a promising ingredient for producing plant-based emulsions.

The effect of hydrothermal treatments, high‐pressure homogenization (HPH) and their combined effects on faba bean protein isolate (FBI) and concentrate (FBC) dispersions was investigated. With HPH, a significant reduction in particle size was observed for FBI but not for FBC. For FBI, dispersion stability under accelerated gravitation was significantly improved by both hydrothermal and HPH. For FBC, hydrothermal treatment had a negative effect on dispersion stability unless it was combined with HPH. The protein dispersibility of FBI increased, and FBC decreased with increasing temperature. Upon HPH, the protein dispersibility of FBI dramatically improved, making it almost completely soluble. All FBI dispersions had a higher surface charge compared to FBC. SDS PAGE profile showed strong protein crosslinking in the original FBI, leading to a loss of legumin and vicilin bands, which were visible in a more native state of FBC. Physical modifications did not significantly affect the viscosities except for a significant increase in FBC heated at 75°C due to starch gelatinization. The equilibrium interfacial tension of the modified FBI was significantly lower than the FBC. Analysis of dynamic interfacial adsorption showed that FBI had a much faster initial diffusion (beyond detection limit) towards the interface than FBC. Physical modifications improved the surface hydrophobicity of the proteins, leading to faster interfacial adsorption. Overall, FBI dispersions had improved functional properties compared to FBC, and HPH had a more significant effect than hydrothermal treatments. Physically modified FBI could be a promising emulsifier in various food applications.

Formation and characterisation of concentrated emulsion gels stabilised by faba bean protein isolate and its applications for 3D food printing

In order to evaluate the freeze-thaw stability of mung bean protein isolate (MPI)-stabilized emulsions and its relationship with protein structure, proteins of eight mung bean varieties were compared. The results revealed that MPIs prepared from all eight varieties were mainly composed of five subunit bands, with albumin and globulin content ranges of 188.4–310.3 and 301.1–492.7 mg/g total protein, respectively. Protein structural analysis revealed that random coil structure (32.34–33.51%) accounted for greater than 30% of MPI secondary structure. Meanwhile, analysis of protein properties revealed emulsifying activity index (EAI), emulsifying stability index (ESI) and flexibility value ranges of 6.735–8.598 m2/g, 20.13–34.25% and 0.125–0.182, respectively. Measurements of freeze-thaw stability of MPI emulsions demonstrated that exposures of emulsions to multiple freeze-thaw cycles resulted in significantly different emulsion creaming index, oiling-off, particle size and zeta potential values for the various emulsions. Moreover, the stabilities of all eight protein emulsions decreased with each freeze-thaw cycle, as demonstrated using optical micrographs. The correlation analysis method was used to study the correlation between the original structures, emulsifying properties of proteins and the freeze-thaw stability of MPI emulsions. Correlation analysis results revealed significant relationships between albumin content, subunit bands with a molecular weight of 26.9 kDa and emulsifying properties were significantly related to the freeze-thaw stability of MPI emulsion. Thus, by determining these indicator values, we can predict the freeze-thaw stability of MPI-stabilized emulsions.

Modulating physicochemical and interfacial properties of faba bean proteins under thermal treatment and pH shifting: implications for emulsion stabilization.

Extraction, physicochemical characteristics and functional properties of Mung bean protein