Food Hydrocolloids最新文献

The present investigation was carried out to evaluate the impact of cold plasma at various power levels (170, 200, and 230V) and for different times (5, 10, and 15 min) on gelatin extracted from buffalo bone to ascertain the difference in physicochemical and functional parameters of untreated and cold plasma treated gelatin. An increase in porosity and angle of repose, and decrease in flow characteristics were observed. The etching phenomenon of cold plasma enhanced surface area, and hence increased viscosity. An increase in the elastic behaviour of gelatin was detected from G' (Storage Modulus) and G" (Loss Modulus). The relative crystallinity dropped to 39.45% in the control sample and 36.9% in the treated samples on XRD as an effect of active plasma species. FTIR revealed minor differences in peak intensity, without a new chemical group. Gelatin's microstructure and surface topography were revealed via SEM investigation. The DSC analysis demonstrated an increase in glass transition (Tg) temperature of gelatin molecules due to alteration in chain dynamics and intermolecular interactions. Moreover, gelatin films prepared from cold plasma treated gelatin showed significant improvement in their tensile strength and mechanical properties suitable for development of packaging films.

The transition toward sustainable and health-conscious diets has intensified plant-based proteins, particularly pea protein. This research explored the gelation mechanisms of pea protein with κ-carrageenan by high-pressure processing (HPP) as an alternative to traditional thermal methods. Suspensions containing 15% pea protein with 0.1–1% κ-carrageenan were subjected to HPP at 100–600 MPa for 5–30 min. Increasing κ-carrageenan concentration reduced the pressure required to obtain good gels, rendering HPP more energy efficient. Pea protein gels with 1% κ-carrageenan at 600 MPa demonstrated a 27-fold increase in compressive strength compared to 15% pea protein alone by HPP and over 5 times the strength of heat-induced counterparts. Gel textures could be tailored by modulating HPP conditions and κ-carrageenan concentrations. Fourier transform infrared spectroscopy, confocal laser scanning microscopy, and scanning electron microscopy characterized protein unfolding, phase separation, and network formation to study the gelation mechanisms. Results revealed that HPP induced protein tertiary structure unfolding, facilitating phase separation and uniform submicron κ-carrageenan particle distribution in the protein matrix. This, along with a more compact protein network induced by HPP, enhanced gel strength, compensating for limited cysteine in pea protein for disulfide bonds. Higher pressures intensified protein unfolding and aggregation, with κ-carrageenan particles evenly distributing into smaller particles, further strengthening gel structures. Conversely, heating-induced gelation caused more random protein aggregation, leading to coarser and weaker gel networks. This research highlights HPP's effectiveness over traditional heating methods in preparing strong pea protein gels with minimal κ-carrageenan and provides preliminary insights into tailoring HPP and κ-carrageenan for desirable gel textures.

Nonionic emulsifiers (NE) are widely used in sponge cakes because they can effectively improve the foaming properties of whole egg liquids (WEL). The WEL are rich in protein, lipids and water, forming air-water and oil-water interface during whipping and foaming. However, different NE plays different roles in the interface. No systematic study has been conducted on the stabilization mechanism of WEL by NE. This study first investigated the effect of different NE on the foaming properties of WEL. It was found that WEL with sucrose ester-9 (SE-9) had the highest foam stability (FS) (92.52%), while that with Tween 80 had the lowest (75.55%). It was found that this was related to the higher interfacial protein substitution ability of Tween 80. Next, free triglyceride content and CLSM analysis confirmed that NE promoted the formation of more oil-water interfaces in the foam. Moreover, NE could improve FS by reducing droplet size and increasing viscosity. Finally, the higher surface activity of NE than proteins was demonstrated by interfacial adsorption kinetics and dilatation rheology. SE-9 interacted with proteins at the air-water interface to enhance interfacial rigidity, whereas adsorption of Tween 80 led to a decrease in the rearrangement rate. The results also showed that the formation of oil-water interfacial films was dominated by the adsorption of NE. This study illustrated how different NE stabilized air-water and oil-water interfaces, and the effect of synergistic/competitive interactions with proteins on the stability of the interfaces. This will provide new insights into the stability regulation of WEL foam.

Plant-derived proteins like rice protein are considered an ideal source for yielding amyloid fibrils due to sustainability and affordability. However, the inherent low solubility of rice protein often restricts its self-assembly capability under common fibrillization protocols. Hence, this study comprehensively investigated the effect of modification on the self-assembly behavior, protein structure and foaming properties of rice protein and its components. The modification facilitated the transformation of α-helix to β-sheet, promoting fibrils formation. All modified proteins, except rice protein, exhibited significantly increased zeta potential values. AFM results revealed that the modified rice protein and globulin fibrils exhibited entangled aggregation behavior, while the glutelin fibril was notably extended, with several micrometers in length. Additionally, modification promoted the aggregation of albumin and prolamin particles to form short and straight fibrils. Amino acid analysis indicated that the content difference of amino acids with different characteristics and the change of aromatic amino acid interaction caused by modification may lead to different self-assembly behavior of the same protein. Furthermore, the foaming capability and stability of most protein fibrils were significantly improved by the modification. These findings provide valuable insights into the regulation of plant-derived protein fibrillation through modification.

Lupin protein isolate (LPI) has high nutritional value and good foaming properties around neutral pH; however, its functionality becomes poor at acidic pH, due to reduced protein solubility. The addition of pectin to LPI can increase its solubility at acidic pH and hence improve protein functionality. Here, we investigated the air-water interfacial and foaming properties of LPI-pectin (1:1) mixtures at pH 3.5–7.0. We used interfacial shear and dilatational rheology, characterized the air-water interfacial microstructure with AFM of Langmuir-Blodgett films, and linked the results to the foaming properties of the LPI-pectin mixtures. Based on the phase diagram, LPI and pectin formed co-soluble mixtures at pH 6.0 and 7.0, while LPI-pectin electrostatic complexes were formed at pH 3.5 and 4.0. In the co-soluble mixtures, proteins diffused faster towards the air-water interface than the electrostatic complexes, due to smaller particle sizes of the proteins. Their air-water interfaces showed distinct differences with respect to microstructure and mechanical properties. The interfaces stabilized by co-soluble mixtures were dominated by protein aggregates, leading to weaker interfaces in response to shear and dilatational deformation, while the complexes formed thicker and denser polymeric air-water interfaces that were stiffer and more solid-like. As a result, the complex-stabilized foams were more stable than those stabilized with co-soluble mixtures. Findings from this study indicate that soluble LPI-pectin complexes formed at pH 3.5 and 4.0 were more efficient in improving interfacial and foaming properties of LPI than the co-soluble mixtures at pH 6.0 and 7.0, which can be used to tailor the properties of acid aerated products stabilized by LPI.

High-internal-phase emulsions (HIPEs) has been increasing interest owing to their large surface area and controllable flow behavior, however, their heavy addition of emulsifiers, e.g., surfactants and surface-active particles, leads to high cost and emulsifier abuse. To solve these issues, we report a new strategy to prepare HIPEs by solely adding a surface-inactive, hydrophilic cellulose nanofiber (CNF). Compared to conventional HIPEs, the highly flocculated CNF is closely packed in the liquid films between oil droplets instead of anchoring at the oil-water interfaces, as referred to the inter-droplet jamming. An efficient jamming behavior is observed at a low CNF concentration (as low as 0.075 wt%) and at very high volume fractions of oil (near 0.85), maintaining the HIPEs over timescales of two years, without the liquid drainage or phase separation. This unexpected stability is mainly attributed to the increase by dozen orders of magnitude in the viscoelasticity of the jammed films as compared with that in the bulk phase, generating a significantly spatial barrier to prevent the depletion attraction between droplets. This simple approach should offer a new pathway to achieve nature-inspired, pure and controlled materials.

Fish oil contains omega-3 polyunsaturated fatty acids, but their poor oxidation stability and gastrointestinal digestion rate led to the low bioavailability. Oleogels could improve the stability of EPA and DHA, so the effect of beeswax (BW)-based fish oil oleogels (FOGs) on the stabilization mechanism and lipid digestion of bi-layer emulsions was investigated. The results showed that the enhanced BW crystals lowered the myofibrillar protein (MP) unfolding along with the decrease in β-sheets, hydrophobic force and disulfide bond, thus reducing the interfacial adsorption capacity and emulsion stability. The enhanced BW formed the rigid crystal network structure and improved the crystal size in the inner layer. The suitable FOG addition (4 wt%) enhanced the unfolding of advanced structures in the outer layer, and the exposure of more hydrophobic groups and disulfide bonds facilitated the interfacial adsorption, thus reducing the size. The final release rate of FFAs significantly decreased with the increasing BW, and significantly increased and decreased with the increasing FOG. BW and FOGs could induce the changes in spatial conformation, and the exposure of hydrophobic groups and disulfide bonds affected the lipase contact at the interface. BW and FOG could adjust the crystal network structure in the inner layer and spatial conformation in the outer layer, thus improving the stabilization and lipid digestion of bi-layer emulsions. This study can provide a theoretical basis for developing DHA and EPA food.

In order to solve the problem of poor performance of giant squid gel, this study proposed a method to induce the aggregation of giant squid protein molecules by exogenous additives to improve its gel performance. The particle size, zeta potential, free sulfhydryl group, carbonyl group and hydrophobic index of protein solution were characterized by laser light scattering, fluorescence spectrum and ultraviolet spectrum, and the effect of egg white protein (EWP) on myofibrillar protein (MP) aggregation was analyzed. In the presence of EWP, the density and R_g/R_h value of protein particles decreased significantly after mixing for 600 min, indicating that the interaction between MP and EWP protein could be enhanced by embedding appropriate amount of EWP in the middle of MP protein. With the increase of the proportion of egg white protein, the blue shift of the maximum absorption wavelength of endogenous fluorescence in the mixed protein solution decreased. In the range of 25–65 °C, the change rates of surface charge, free sulfhydryl group, carbonyl group and surface hydrophobicity decreased, which proved that EWP inhibited the self-aggregation rate of MP molecules during the heating process, and induced its gel by interspersing between MP molecules to improve the formation of three-dimensional network during protein thermal gel process. Finally, the addition of EWP improved the gel properties of giant squid surimi. This study offered new direction for improving gel properties and promotes the development and application of giant squid.

The study investigated the influence of gelatin (GE) content and the Hofmeister effect on the physicochemical, rheological, and printing properties of high internal phase emulsion (HIPE) gels. Incremental GE content introduced more triple helix structures (junction zones) in the continuous phase of HIPE. By soaking in a sodium citrate (Na₃Cit)-glycerol-water solution, polymer chain bundling, hydrophobic interactions, and abundant hydrogen bonds between GE and glycerol further increased, achieving a more compact crosslinking density and internal network. The optimized HIPE-GE-Cit^3- gel with 1.5 wt% GE displayed improved shape retention, generating smoother and firmer gels with enhanced freezing and heat resistance. Its excellent mechanical strength and viscoelasticity can resist large deformations and maintain reversible structures. HIPE-GE gel with 1.5 wt% GE demonstrated satisfactory printing suitability with clear outlines, favorable visual aesthetics, and minimal dimensional deviation. This post-soaking (Hofmeister effect) also eliminated rough surfaces and visible layered lines, improved mechanical properties and more elastic networks. The printed HIPE-GE_1.5-Cit^3- gel with higher rigidity and elasticity impeding molecular release, protected encapsulated resveratrol against degradation, especially from heat, and enhanced the release rate in the small intestine, achieving sustained release. This work produced customizable HIPE gels by 3D printing with multiple advantages to develop personalized nutraceutical carriers with high-temperature tolerance.

The older adult population is greatly affected by malnutrition. This condition can arise from inappropriate micro and micronutrient intake, as well as due to experienced age-related changes. For instance, a significant number of older adults suffer from dysphagia. Thus, the development of foods with adequate consistency/viscosity are vital for overcome this condition. Within this framework, novel functional thickened drinks were developed and tailored for the older adult population, by using chia seed gum as the thickening agent enriched with vitamin D3-loaded solid lipid nanoparticles (SLN). Rheological properties of different thickened drinks formulated with water, semi-skimmed milk or orange juice were optimized using a central composite rotational design. Results showed that SLN delivered high vitamin D3 encapsulation efficiency with high concentration (i.e., 32 IU/mg). The different drink matrices attained distinct rheological properties, being observed that the viscosity and consistency attained with the same thickening agent concentration was higher in more complex matrices. An optimized formulation containing the tolerable upper intake level (ca. 4000 IU) was selected to study the vitamin D3 release and bioaccessibility on older adults’ population using a dynamic in vitro gastrointestinal digestion system. Once more, strong matrix effects were observed and significantly affected vitamin D3 release profile, bioaccessibility and recovery during the in vitro digestion. Additionally, the drinks enrichment with SLN-VitD3 did not display a negative effect on cells viability. The development of novel functional thickened drinks tailored for older adults could provide a safer swallowing and improved vitamin D3 intake.