Food Biophysics最新文献

Phlorotannins (PHT) are phenolic substances found in marine brown seaweeds that have a lot of different biological effects. However, their poor stability restricted their usage in different fields. Here, we encapsulated PHT using a freeze-drying technique. Process parameters, including wall material type (maltodextrin, whey protein, and their combination), wall concentration (0.03–0.1 w/v), and core-to-wall ratio (2–5), were optimized using the response surface method with a central composite design (CCD) to attain the best capsule. The optimum encapsulation with the highest PHT efficiency (85.67%) and antioxidant activity (67.34%) was produced with a whey protein/maltodextrin blend encapsulating at 0.03 w/v and 5 PHT-to-wall ratios. Findings from SEM studies on optimal capsules revealed that the particles are irregular in shape, with some pores on the surface. Furthermore, the FTIR study validated the encapsulation of PHT, and the TGA data suggested that encapsulation enhanced the thermal stability of PHT. Further, encapsulated PHT (En-PHT) was added to pasteurized milk to increase its shelf life. The findings indicate that the addition of En-PHT restricts microbiological proliferation, prolonging milk’s shelf life from 4 days to 8 days while maintaining acceptable sensory attributes. This study suggests that En-PHT could be exploited as an ingredient to produce new, functional milk.

This research prepared an antibacterial active packaging material based on carboxymethyl chitosan/polyvinyl alcohol (CMCS/PVA) loaded with cerium dioxide nanoparticles (CeNPs), and evaluated its potential application in fruit preservation. The results of Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD) indicated that CeNPs were uniformly dispersed in the film matrix, and the components of the film exhibited good compatibility. The composite films containing CeNPs also exhibited excellent mechanical properties. Compared with the CMCS/PVA (CP) film, their tensile strength increased from 15.22 MPa to 30.72 MPa, and the elongation at break rose from 43.17% to 101.79%. Meanwhile, the incorporation of CeNPs enhanced the barrier properties of the composite films. The composite film with 5% CeNPs exhibited excellent ultraviolet shielding ability, with a transmittance of nearly 0% in the range of 200–315 nm, and possessed outstanding gas barrier performance, with the water vapor permeability (WVP) decreased by 35%. In addition, the CP-CeNPs composite film exhibited stronger DPPH and ABTS radical scavenging activities (50.55%, 77.12%), with inhibition rates against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) reaching 99.66% and 96.80%, respectively. The composite film showed no toxicity to RAW 264.7 mouse macrophages, with a cell viability of over 80%. Finally, it extended the shelf life of strawberries by 7 d at 25 °C. The findings demonstrated that the composite film provided a novel approach for preparing active packaging materials and showed promising potential in fruit preservation packaging applications.

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Both lutein and chlorophyllin are vital natural pigments. However, the application of lutein has been limited due to its low environmental stability and poor bioavailability. Herein, lutein/Cu-Chlorophyllin (L-Chls) composites have been fabricated via a simple and mild solvent-mixing process at room temperature. Compared to the pristine lutein, the synthesized L-Chls showed 5.2 times higher photostability and 6.9 times better antioxidant ability. The retention rate and thermostability in the air also improved by 77% and 23%, respectively. The experimental results reveal the energy/electron co-transfer at the interface of lutein and Cu-Chl, and a possible mechanism for the enhanced photostability and antioxidant ability of the L-Chls has been proposed. This work provided a feasible strategy to improve the stability and antioxidant ability of lutein, and can also be expanded to the functional food and pharmaceutical field.

In this study, we investigated the physicochemical and rheological properties of xanthan gum (XG) in milk protein isolate (MPI)-based aqueous and emulsion systems at varying MPI concentrations (0–2.0%). MPI-based aqueous systems exhibited relatively higher ζ-potential values (-12.1 to -14.1 mV) than emulsion systems (-21.2 to -27.8 mV), suggesting a conformational transition of MPI during emulsification. The ζ-potential of the emulsion system decreased with increasing MPI concentration, leading to enhanced stability. The addition of XG further improved stability by forming a dense viscoelastic 3D network that restricted particle mobility. The intrinsic viscosity of XG in both systems decreased with increasing MPI concentration, indicating the formation of a more compact conformation due to electrostatic repulsion with MPI or emulsion particles. Consequently, the apparent viscosity and viscoelastic moduli values for XG increased, reflecting stronger intermolecular interactions among closely packed molecular chains. Notably, a more pronounced increase was observed in the emulsion system. The enhanced rheological properties are likely attributable to the formation of more negatively charged particles upon emulsification, which promoted XG molecule contraction in the emulsion system. This conformational transition facilitated interactions between negatively charged XG and positively charged peptide domains protruding on the emulsion particle surfaces. These findings highlight that emulsification alters MPI conformation, thereby changing its interaction with XG and leading to distinct rheological behaviors of XG in aqueous and emulsion systems. With this in mind, the design of gum-based thickeners for dysphagia should account for beverages containing emulsified phases to achieve optimal texture, stability, and swallowing safety.

Lycopene extract from tomato peel by-products was encapsulated in oil-in-water (o/w) nanoemulsions of a combination of b-cyclodextrin and dextran prepared by ultrasonic emulsification. The stability of the nanoemulsions was assessed through analytical photocentrifugation, followed by spray drying to produce nanoencapsulated powders. The characterization of the lycopene nanoparticles included assessment of encapsulation efficiency, antioxidant activity, and physicochemical and structural properties. Extending the ultrasonic emulsification process to 16 min resulted in the production of nanoemulsions with satisfactory physical stability, achieving a higher encapsulation efficiency of 96.17%, and improved solubility with a percentage dispersion in aqueous media of 97%. The powders produced, with a water content and water activity of 2.3% and 0.33, respectively, confirmed the effectiveness of the spray drying process. Microscopically observed particles showed a spherical nanoscale morphology with an average diameter of 100.87 ± 1.23 nm. This finding indicated that ultrasonic treatment of the emulsions led to a substantial reduction in particle size. The zeta potential of the nanoparticles, recorded at -20.09 mV, indicated that the particles exhibited a moderate stability. This observation was corroborated by the results of storage for 30 days at different temperatures in dark or light conditions. The lycopene nanoparticles produced demonstrated acceptable stability, with lycopene degradation levels of 9%, 14%, 21%, and 26% at 4 °C and 25 °C in light and at 30 °C and 40 °C in the dark, respectively. This study demonstrates that nanoencapsulation by ultrasonic emulsification is a promising method for producing lycopene nanoparticles with high solubility and potential for food applications.

In this study, we investigated the development of gum Arabic (GA)-based composite coatings functionalized with keratin (K) and cinnamon oil (CO) to enhance the physicochemical, nutritional, and microbial stability of tomatoes. Coating formulations containing GA-K-CO_0.1 (27:3:0.1, v/v/v) and GA-K-CO_0.5 (27:3:0.5, v/v/v) were developed and applied as coatings. Mature green tomatoes were treated with GA-K-CO_0.1 and GA-K-CO_0.5 and stored at 27.5 °C and 80.7% relative humidity (RH) for 20 days, with quality assessments at 5-day intervals. Formulations with a GA-K-CO_0.1 concentration extended the shelf life of tomatoes by up to 5 days under ambient conditions. This was achieved by significantly reducing weight loss by 31.9%, decay incidence by 33.3%, and exhibiting significant antifungal activity (p < 0.05) compared with the uncoated control, which was coated with distilled water. The tomatoes coated with GA-K-CO_0.5 showed about a 6.21% retention in moisture content, total soluble solids, and a rise of roughly 60% in antioxidant capacity compared with control group. The formulation with a lower level of cinnamon oil in GA-K-CO_0.1 showed a significant (p < 0.05) retention in β-carotene and lycopene levels, and further enhanced nutritional and visual quality, as well as its potential to inhibit bacterial and fungal growth. The gum Arabic-based coating functionalized with keratin and cinnamon oil presents a novel and sustainable method for postharvest tomato preservation, holding considerable promise to lower losses and improve food quality in supply chains.

The valorization of hop (Humulus lupulus L.) residues from the brewing industry was investigated through supercritical CO₂ extraction, followed by chemical characterization of the oleoresin and the formulation of nanoemulsions for the control of Xanthomonas citri, the causal agent of citrus canker. The oleoresin yield from previously processed hop residues was 1.87 ± 0.03 g per 100 g of dry biomass. GC–MS analysis identified 19 volatile compounds, with humulene (28.20%) and caryophyllene oxide (19.82%) as the predominant constituents. The oil also contained significant levels of palmitic acid (42.78%) and oleic acid (39.99%), and retained α-acids, including cohumulone (0.42%) and adhumulone + humulone (1.46%). Two emulsions were prepared: a water-based formulation (F1) and a chitosan-based formulation (F2). F2 exhibited a larger particle size (508.7 nm), high colloidal stability (+ 74.3 mV zeta potential), and bactericidal efficacy, achieving complete inhibition of X. citri at a concentration of 0.03125% (312.5 µg/mL). In contrast, both F1 and the crude oleoresin required concentrations of 2% to exhibit observable antimicrobial activity. Transmission electron microscopy and atomic force microscopy analyses confirmed spherical nanoparticles with uniform morphology and smooth surface for F2. These findings support the sustainable reuse of hop processing residues in the development of effective, low-toxicity biocontrol agents, with commercial potential for integrated citrus disease management.

All kinds of methods (physical, chemical and enzymatic) was used to enhance the functional properties of plant proteins. Soybean protein isolate (SPI) is a very important vegetable protein with higher nutritional values. The aim of the study was to evaluated the alternative application of hydroxyl-radical as a moderate‌ and homogeneous‌ protein handing technique to improve the functional qualities‌ of SPI. SPI was treated in H₂O₂ solutions at different concentrations (0, 0.1, 1, 5, 10 and 15 mM) for 24 h and then freeze-dried. The oxidization induced more porous microstructure in SPI surface. Compared to the raw SPI, the total sulfhydryl group, water/oil holding capacity, enthalpy (peak 1 and peak 2), solubility of SPI with the increase of H₂O₂ concentration decreased significantly (p < 0.05), which decreased by 40.03%, 7.30%, 39.46%, 12.07%, 16.71%, and 29.00% at 15 mM H₂O₂, respectively, while H₂O₂ prompted a significantly increase in protein carbonyl content (p < 0.05). FTIR confirmed that oxidation resulted in the gradual loss of α-helical and β-sheet structures with the concomitant increase of β-turn and random coil structures (increased by 28.84% and 42.89% at 15 mM H₂O₂, respectively). Compared with the raw SPI, the moderate H₂O₂ concentration (1 mM) enhanced emulsifying properties, while lower (0.1 mM) and higher (5 mM) H₂O₂ concentration significantly increased the foaming properties and the value of zeta potential, respectively (p < 0.05). With the increase of H₂O₂ concentration, the intensities of volatile compounds were strongly influenced by the oxidation levels of SPI, some compounds increased, some decreased, which was likely owing to the structure changes of modified SPI. These results indicated that the potential of H₂O₂ hydroxyl radical-generating system can be as an innovative‌ and productive‌ way to enhance functional properties of SPI, and also provide a key direction for developing high-performance plant protein ingredients in food industry.

This study evaluated the synergistic effects of 4-minute ultrasonic (US) pretreatment (135 W) combined with mixed starter cultures (Lactiplantibacillus plantarum CD101 and Staphylococcus simulans NJ201) on the quality attributes of dry-fermented sausages. Three control groups were established: CK (uninoculated), CL (inoculated with starter cultures only), and SCL (inoculation + US treatment). Ultrasonic treatment accelerated early lipid oxidation, but by the end of fermentation, the TBA value remained at a safe level and was significantly lower than that of the CK group. Protein degradation was significantly enhanced: Non-protein nitrogen (NPN/TN) in the SCL group reached 15.41%, significantly higher than in the CL group (14.74%) and CK group (13.82%) (P < 0.05). Total free amino acids in the SCL group reached 449.46 mg 100 g⁻¹, 9.4% higher than the CL group (410.67 mg) and 31% higher than the CK group (343.66 mg). SDS-PAGE revealed accelerated degradation of myosin heavy chain and actin in the SCL group, accompanied by increased < 20 kDa peptide fragments. These data indicate that ultrasonic pretreatment promotes proteolysis and flavor precursor formation without compromising oxidative stability, providing an efficient approach to enhance traditional fermented sausage production processes.

This study investigated the impact of magnetic particle-incorporated water-in-water (W/W) Pickering emulsions on the aggregation capacity and stability of encapsulated probiotics. The results demonstrated that the incorporation of magnetic particles did not compromise the structural integrity of the W/W Pickering emulsion under varying environmental conditions, and that the emulsion breakage was controllable under magnetic field conditions. The probiotics encapsulated in the magnetic W/W Pickering emulsion had an enhanced aggregation ability. The survival rate after spray drying of emulsion encapsulating probiotics with magnetic particles was 81.16%, a significant improvement of 12.62% compared to the control group (68.54%). This finding underscores the protective role of magnetic particles in mitigating the detrimental effects of environmental stressors on probiotic viability. Furthermore, during simulated gastrointestinal digestion, the encapsulated probiotics displayed a cell viability of 1.00 × 10⁸ CFU·g⁻¹ after gastric digestion and 9.45 × 10⁷ CFU·g⁻¹ after intestinal digestion. The excellent biocompatibility of this encapsulation system underscores its potential as an advanced material for probiotic encapsulation, providing a promising strategy for developing more robust and shelf-stable probiotic-based products.

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