Food Biophysics最新文献

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.

This study investigates the dual role of essential oil components (EOCs) in enhancing microbial safety and shaping sensory perception, specifically against Escherichia coli O157 in orange juice. Four EOCs—carvacrol, citral, linalool, and limonene—were tested in nanoemulsified (n-EOC) and suspended (s-EOC) forms, individually and at low heat. Nanoemulsified EOCs showed up to a 13-fold increase in antimicrobial efficacy, achieving a 5-log reduction in bacteria more efficiently than s-EOCs or heat alone. This synergistic effect enabled lower processing temperatures while maintaining juice quality. Molecular docking studies revealed strong interactions between EOCs and the bitter receptor TAS2R46, suggesting potential effects on bitterness perception. Computational predictions indicated specific binding affinities of each EOC to TAS2R46, highlighting their potential influence on sensory acceptability. Sensory analysis using principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed distinct groupings based on EOC composition, with significant differences observed between control (P1), limonene (P2), carvacrol (P3), linalool (P4), and citral (P5) samples. Samples treated with mild heat at 54 °C for 10 min showed similar clustering, with minor variations related to acidity, a key factor in acceptability. The study underscores the importance of balancing antimicrobial performance with sensory attributes to optimize consumer satisfaction, demonstrating the potential of nanoemulsified EOCs to enhance both microbial safety and sensory quality in food products. By fine-tuning combinations of EOCs with mild heat, this research offers valuable insights into preservation strategies that ensure both safety and consumer appeal.

Anemia is globally linked to dietary iron deficiency, potentially concerned by a shift from meat-based diets to plant-based ones with less bioavailable non-heme iron. This study compared the iron bioavailability of two commercial plant-based burgers (PBB1 and PBB2) with that of an animal-based burger (ABB). PBB1 and PBB2 contain 2.37 mg and 2.45 mg, respectively, while ABB contained 1.6 mg of iron per 100 g. The iron bioavailability (ng ferritin/mg protein) of PBB2 (5.98 ± 0.41) and PBB1 (4.70 ± 0.33) was higher than ABB (4.05 ± 0.29) as determined using a Caco-2 cell model. The main inhibitors and enhancers of iron bioavailability were also investigated. Phenolic compounds were found to increase iron bioavailability in the PBBs, suggesting they may not always act as antinutritional factors. Phytic acid content had no significant impact on iron bioavailability. There was a positive correlation between the antioxidant properties of the digested burgers and iron bioavailability. These findings suggest that PBBs can match or exceed the iron bioavailability of ABB, offering potential solutions for global nutritional challenges.

This research compared three extraction methods (ammonium sulfate precipitation; ASP, organic solvent precipitation; OSP, and isoelectric point precipitation; IEP) to optimize protein isolation from Cordyceps militaris fruiting bodies for food applications. The ASP method demonstrated the greatest productivity, with a yield of 20.12% and a protein content of 78.90%. Moreover, it exhibited notable foaming capacity (95.33%) and stability (87.00%). It also showed significant solubility, with emulsion activity measuring 363.83 m²/g and emulsion stability lasting 26.17 min. The OSP technique exhibited significant solubility with a rate of 92.34%, as well as a considerable water holding capacity of 2.06 mL/g and oil holding capacity of 1.78 mL/g. The protein isolates showed major protein bands concentrated in the molecular weight range of 10–25 kDa, with additional bands observed outside this range under both reducing and non-reducing conditions. The FT-IR spectra revealed that the isolates had similar amide bands (amide I, II, and III), suggesting consistent protein secondary structures and molecular interactions. Microstructural analysis highlighted that the ASP and OSP isolates had smooth surfaces, but the IEP isolates displayed flakier textures. The protein isolates from C. militaris showed differences in their characteristics when extracted by different methods. Among these methods, ASP provided the best results for potential food applications.

The objective of this study was to assess edible coatings composed of xanthan gum and pectin (PecXG) enriched with essential oils (EOs) of Sweet Orange (Citrus sinensis L.) peel towards preservation of chicken meat. The EOs was obtained by ultrasound-assisted hydrodistillation method. The compositional analysis of the EOs, performed by GC–MS, identified D-Limonene as the major constituent. Varied content of EO was incorporated into the PecXG films. The successful infusion of EO was observed from FTIR and XRD studies. The EO incorporation dose-dependently improved the thickness, tensile strength, porosity and hydrophobicity of the films. On the other hand, a lowering in water solubility, moisture content, oxygen and water vapor permeabilities were noted with increasing EO content in the films. A noticeable decline in L* and a* with enhanced b*, △E and opacity was witnessed upon increasing the EO content. The EO-infused films displayed a slightly lower degradation temperature with respect to pristine PecXG film. The film with highest EO (PecXG/ EO3) demonstrated significant UV-shielding properties. The inclusion of EO promoted the inhibitory activity of the films against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) free radicals. On the 10th day of chicken meat storage, the uncoated sample demonstrated a weight loss of 13.33% while it was 7.7% for PecXG/ EO3. Also, the uncoated meat exhibited a TVB-N value of 51.02 mg N/100 mg while it was 17.11 for PecXG/EO3. Furthermore, the coatings were biocompatible with L929 cells. The overall results of this study suggest that the developed EO-enriched PecXG edible coatings are potent in chicken meat preservation.

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Quinoa (Chenopodium quinoa) is increasingly integrated into diets due to its high nutritional value, antioxidant activity and health benefits. This study aimed to systematically evaluate the influence of varying germination times (0, 12, 18, 24, and 36 h) on quinoa’s nutritional, physicochemical, functional, antioxidant, anti-nutritional, pasting, thermal, and structural properties. A combination of analytical techniques, including proximate analysis, FTIR, and pasting profile analysis, was employed to investigate these effects. Germination resulted in a significant (p < 0.05) increase in protein and fibre content, while a reduction in ash, fat, and carbohydrates was observed, likely due to enzymatic activity promoting macronutrient mobilization during different germination stages. Functional properties of the flour were altered, with significant (p < 0.05) increases in antioxidant activity (31.32% in total phenolic content, 40.21% in total flavonoid content), attributed to the release of bound phenolic compounds. Antinutritional factors, including saponin and phytic acid, were significantly (p < 0.05) reduced (30.11% and 42.46%), possibly due to enzymatic degradation and leaching. Germination significantly (p < 0.05) decreased setback, breakdown, final viscosity, and pasting temperature, indicating starch breakdown. FTIR analysis revealed shifts in functional groups, reflecting structural changes in the flour, while alterations in morphology and thermal properties were also noted. The findings from this study highlight the role of germination time in modifying quinoa’s nutritional and functional properties for diverse food applications.

Investigations on structure and dynamics of LMP based ionically crosslinked hydrogels important for designing multifunctional materials for applications in energy storage devices. Low Methoxyl Pectin (LMP) solutions were prepared using solution casting technique. Stoichiometric ratios (SR) of 0.5, 1, 1.5 and 2 were selected for Ca²⁺ and Fe³⁺ ion doping. Rheology, electrochemical impedance spectroscopy (EIS), SEM studies were performed. The storage modulus (G’) and loss modulus (G”) with Ca²⁺ and Fe³⁺ ions showed a power law relationship, which are in good agreement to morphological changes in hydrogels. Rheology results showed a power law relationship with increasing Ca²⁺ and Fe³⁺ ion concentration. LMP/Ca²⁺ hydrogels showed dc conductivity (0.38 S/cm-1.26 S/cm), whereas LMP/Fe³⁺ hydrogels (0.37 S/cm–0.81 S/cm). Kramer’s Kronig relation was used to derive imaginary part (({varepsilon {^{prime prime}}_{der}})) of permittivity to avoid conductivity contributions. Debye model function was used for fitting dielectric relaxation (segmental relaxation) peak. The dc conductivity of LMP was ≈1.52 S/cm with dipolar relaxation time of ≈1.95 × 10⁻⁴ s. Dielectric relaxation times were (1.9 × 10⁻⁴ – 7.1 × 10^− 4) for LMP/Ca²⁺ hydrogels, whereas, greater change (7.9 × 10^− 4 – 2.5 × 10⁻³) in relaxation time was observed for LMP/Fe³⁺ hydrogels. Electrode polarization was higher for LMP/Fe³⁺ over LMP/Ca²⁺ hydrogels, which can be used in energy storage devices.

This study successfully developed plant-based bigels using Bakla starch hydrogel and glycerol monostearate oleogel in various ratios, ideal for use as fortified ingredient substitutes or food analogs. The effects of varying oleogel-to-hydrogel ratios on the microstructure, rheological properties, and stability of bigels were analyzed. As the oil phase increased, the system transitioned from an oleogel/hydrogel structure to a bicontinuous phase, a characteristic of bigel systems. The experimental results indicated that an increase in oleogel content led to an improvement in the hardness, viscosity, and storage modulus of the bigels. Moreover, bigels with oleogel to hydrogel ratios of BG 50:50 to BG 80:20 demonstrated increased hardness, ranging from 134.74 ± 0.33 g to 269.55 ± 0.17 g. X-ray diffraction revealed a broad peak around 20° 2θ, indicative of the amorphous nature of the oil component. FTIR showed that the structural configuration of bigels is governed by physical and steric interactions, reflecting the distinct characteristics of each phase without forming new bonds. The findings demonstrated the potential to create starch-based bigels with desirable, mechanical, rheological properties and stability by adjusting the hydrogel-to-oleogel ratio offering sustainable, low-calorie fat alternatives for novel food products.