Food Biophysics最新文献

Pickering double emulsions, characterized by their multi-chamber and multi-interface structure, historically faced challenges in physical stability due to solute exchange and film fusion, constraining their use in food, cosmetic, and pharmaceutical sectors. This study introduces an innovative approach to structuring the intermediate oil phase of these emulsions by employing crystallizable monoglycerides. We strategically manipulated the distribution of monoglycerides across the internal and external interfaces, as well as within the oil phase, to enhance emulsion stability. Our findings revealed that the distribution pattern of monoglycerides significantly influenced the emulsion’s resistance to solute exchange and film fusion. Notably, the internal interface crystal barrier effectively inhibited solute exchange, while the distribution pattern at the external interface showed the greatest reduction in membrane fusion. Additionally, crystallization within the oil phase is found to be sensitive to creaming, which is exacerbated under conditions of osmotic pressure or freeze-thaw cycles. Comprehensive rheometer and tribological testing indicated that monoglycerides distributed at the interface, which withstand processing conditions, imparted the double emulsions with enhanced elastic rheological properties and improved stiffness. This research contributes novel insights into the structure-function relationship of multiple emulsions. It opens up new avenues for engineering the interfacial structure and optimizing the physical stability and rheological properties of emulsion systems, making it a significant advancement in the field.

This work aimed at understanding the effect of heat treatment on the properties and functionalities of pea protein isolate (PPI). PPI was characterised using thermogravimetric methods coupled with evolved gas analysis, differential scanning calorimetry, and X-Ray powder diffraction. As water is an integral component in determining protein properties, inelastic neutron scattering was further used to study water populations in the PPI powder. Hydration time was identified as key in determining solubility. Heat treatment resulted in partially denatured, more soluble, less thermodynamically stable, and less crystalline PPI compared to the control. Heating, often associated with protein aggregation and particle size increase, was found to reduce PPI particle sizes, which was attributed to the disruption of non-covalent interactions. During emulsification, these features enhanced formation of smaller drops, stable against coalescence. Compared to the control, the heat-treated PPI produced emulsions with increased shear thinning (power law index of 0.6 compared to 0.9) and consistency (≈10 times higher), as it has been previously reported for emulsions with fine, compared to coarse, droplets. Acid-induced gels of the heat-treated PPI were ≈4 times more elastic (G’) compared to the control. Overall, this work contributes towards the design of plant-based foods with predictable characteristics by understanding the link between protein physicochemical properties and food functionality.

In this study, extraction of protein from sesame seed press cake (SSPC) was optimized. SSPC protein isolate was subjected to enzymatic hydrolysis and both SSPC protein isolate and hydrolysates were characterized by SDS-PAGE, gel filtration chromatography, Fourier transformed infrared spectroscopy (FTIR) and circular dichroism (CD) spectroscopy. Meatball analogs containing SSPC protein isolate (15 and 20%) were prepared and evaluated for sensory attributes. The extraction at optimized conditions resulted in protein yield of 20.87 ± 0.57% with protein content of 92.1 ± 1.82%. Water holding capacity (WHC) and oil holding capacity (OHC) of SSPC protein isolate were 1.47 ± 0.04 g/g and 5.86 ± 0.10 g/g, respectively. Densitometric analysis showed that 7S globulins (55–60 kDa) were the major protein bands in SSPC protein isolate and this finding was further supported by gel filtration chromatography. CD spectroscopy revealed that SSPC protein isolate contained 23.4% α-helical structure which after hydrolysis was reduced to 12.6%. FTIR analysis revealed the presence of Amide, I, II and III in protein isolate and hydrolysates. The incorporation of SSPC protein isolate resulted in a decrease in fat content whereas, the protein content of meatball analog was increased up to 42.43% in comparison to control formulation (22.68%). The meatball analogs received acceptable sensory scores and the addition of SSPC protein had no overall negative impact on the sensory scores. SSPC protein due to its low cost and functional attributes can be used in the formulation of meatball analogs.

Pickering emulsion gels as versatile soft carriers for encapsulation and delivery of bioactives have shown great prospects for the extensive application in food, cosmetic and medical industry. In this work, zein-based Pickering emulsion gels (ZPEGs) emulsified and stabilized by zein/pectin complex nanoparticles (ZPNPs) were developed as delivery carriers of bioactives. The particle size, zeta-potential, and surface wettability of ZPNPs with different zein-to-pectin mass ratios were systematically evaluated. The optimized ZPNPs with neutral wettability and high surface charge were shown to be capable of rapidly forming and stabilizing O/W Pickering emulsion gels at lower ZPNPs content (1%) and high oil fractions of 0.4–0.6, exhibiting long-term storage stability (over 60 days), excellent viscoelasticity and plasticity (G’ > G"). The microscopy characterization, including SEM and confocal laser scanning microscopy (CLSM), revealed the intuitive network architecture and emulsion interface microstructure of ZPNPs and ZPEGs. As delivery carriers, the curcumin-loaded gels, prepared by encapsulating curcumin either in ZPNPs particles or in the oil phase of emulsion gels, could effectively improve the digestion stability (> 70%) and bioaccessibility (> 40%) under simulated gastrointestinal digestion conditions, furthermore, the curcumin-loading mode in ZPEGs had significant effects on the delivery properties. These results may be of practical importance for the development of zein-based Pickering emulsion gels for encapsulation and controlled release of bioactives, as well as for the rational design and optimization of area-confined co-loading systems.

Food security is increasingly threatened by factors such as population growth, resource depletion, climate change, and unsustainable agricultural practices leading to food loss and waste. Addressing these challenges requires innovative strategies, including enhanced food preservation, functional food development, improving packaging solutions, and rapid pathogen detection. Nanoparticles (NPs), due to their unique physicochemical properties—such as high surface area, reactivity, and antimicrobial activity—offer promising solutions for improving food safety, crop productivity, and sustainability in agriculture. Compared to traditional preservation and packaging methods, NPs provide advantages in antimicrobial protection, active packaging, controlled release systems, and improved mechanical and barrier properties. This review examines the properties, design considerations, and applications of NPs in food and agriculture, highlighting recent research progress, prospects, and potential risks. It also discusses the knowledge gaps, safety concerns, and regulatory challenges, emphasizing the need for further studies to assess toxicity, environmental impact, and risk management frameworks. By providing insights into the potential and challenges of NPs, this review serves as useful resources for researchers, policymakers, and industry professionals, guiding the safe and effective implementation of nanoparticles in food and agriculture.

Encapsulation techniques, particularly Pickering emulsions stabilized by polysaccharide-protein complexes, offer a promising approach for enhancing the protection and functionality of flaxseed oil (FSO) in food applications. This study explores the stabilization of FSO-in-water emulsions using zein protein (Z) combined with either basil seed gum (BSG) or cress seed gum (CSG). SEM revealed that the Z-BSG and Z-CSG complexes formed spherical particles with smooth surfaces, though Z-BSG particles were significantly larger (2354 nm) compared to Z-CSG particles (892.7 nm). The emulsions were assessed for stability, rheological behavior, and droplet size. Emulsions containing 20% FSO stabilized by Z-BSG demonstrated superior stability and increased viscosity relative to those stabilized by Z-CSG. Subsequently, these FSO-loaded Pickering emulsions (PE) were incorporated into functional kiwifruit bars, and their physico-mechanical and sensory attributes were analyzed. Kiwifruit bars containing Z-BSG-PE displayed minimal changes in color compared to those with Z-CSG-PE. Additionally, bars with Z-BSG-PE exhibited higher adhesiveness and chewiness. Samples containing 0.2% and 0.5% Z-BSG-PE were rated the highest in overall acceptability, indicating that BSG provided better sensory properties than CSG. These findings underscore the potential of BSG to outperform CSG in stabilizing Pickering emulsions and enhancing the quality of functional food products such as kiwifruit bars.

Water transport in potato microstructure occurs through symplastic, apoplastic, and transcellular mechanisms. Understanding these microscale behaviors is crucial for enhancing food processing operations and achieving high-quality processed products. In this research, we analyzed low thermal water transport in potato cells. The cell designs included one, two, and four simplified cell configurations, and the CFD method simulated water transport in COMSOL Multiphysics. Three mass concentration equations, based on diffusion, permeability, and capillary diffusivity were used to estimate moisture concentration variation for intracellular, intercellular, and cell wall environments. Then, the velocities of water within the cell, through the cell wall, and between the cells were calculated using the Brinkman equation under periodic boundary conditions. The results indicated that the intracellular water concentration profile for all three designs was similar. At 0.78% cell fraction, there was the greatest difference of 3.22 × 10^− 9 m s^− 1 in average velocity, while the 0.72% cell fraction showed no difference in average velocity for designs. Water concentration simulations indicated that concentration within the cells decreased from an initial value of 4.5 × 10⁴ to a final value of 3 × 10⁴ within 100s. The units’ center temperature increased from initial degrees of 297 K to 330 K in the same period. Intercellular water diffusivity increased with cell fraction. The findings indicate that velocity and diffusivity are influenced by fraction and design, while intercellular fraction rather than cell designs determine mass concentration.

Camelina protein is a new source of plant protein. This work aimed to investigate the structural changes and improve functional properties of ultrasound treated camelina protein isolate (CPI). Structural analysis revealed that ultrasonic treatment did not change the molecular weight distribution of CPI, but increased the content of β-sheet. Moreover, the tertiary structure of CPI was altered under ultrasonic treatment with the tryptophan partially exposed to a polar environment characterized by intrinsic fluorescence spectra. Additionally, under ultrasonic treatment of 15 min, the particle size was reduced by 43%, the surface area between protein and water was increased, and the solubility of CPI was enhanced by 42%. Ultrasonic treatment exposed the positively charged groups inside the protein, increasing the zeta potential (from − 14.9 mV to -9.7 mV). Furthermore, the H₀ was increased due to the destruction of hydrophobic interactions in the protein molecule by ultrasonic treatment, allowing the internal hydrophobic groups to be exposed. As a result, this reduced the hindrance at the air-water interface, increasing the adsorption rate, and improving the emulsifying and foaming properties. The foaming ability of CPI reached 202% at 35 min of ultrasound, which was 1.32 times that of untreated CPI. The foaming stability was best at 25 min. The emulsifying activity index increased from 10.87 m²/g to 14.09 m²/g, and the emulsifying stability index reached the highest value at 5 min. Under ultrasonic treatment, the fragmented protein surface was observed by SEM images. The finding contributes to the effective utilization of camelina protein resources.

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Centella asiatica is a medicinal plant rich in bioactive compounds with potential health benefits. However, its processing conditions significantly influence the retention of these compounds. Therefore, this study investigated the effect of microwave pretreatment on the drying, extraction, and encapsulation of Centella asiatica bioactive compounds. Leaves were subjected to steam and microwave blanching for 30, 45, and 60 s, followed by drying at 30, 40, and 50 °C. Drying kinetics were analyzed using different mathematical models. Ultrasound-assisted extraction was employed to enhance bioactive compound yield, with optimization conducted using a Central Composite Rotatable Design (CCRD). The independent variables included sonication time (15–30 min), solvent-to-solid ratio (10:1–30:1), and solvent concentration (60–90%). The optimized extract was encapsulated using aloe vera mucilage with varying concentrations of maltodextrin and gum acacia, and freeze-dried powders were evaluated for encapsulation efficiency and physicochemical properties. Microwave blanching resulted in a higher drying rate compared to steam blanching and control samples. Blanching for 45 s followed by drying at 50 °C effectively retained bioactive compounds, making it the optimal condition for extraction. The best extraction conditions were identified as 30 min sonication, a solvent-to-solid ratio of 29:1, and a solvent concentration of 90%. The second-order polynomial model fitted well with the experimental data, and multiple regression and ANOVA confirmed the model's reliability. Among the encapsulation formulations, S4 exhibited the highest encapsulation efficiency and superior physicochemical properties. This study highlights the effectiveness of microwave blanching, optimized ultrasound-assisted extraction, and aloe vera-based encapsulation for preserving Centella asiatica bioactive compounds. These findings provide a foundation for industrial-scale processing, ensuring enhanced product stability and quality.