Food Biophysics最新文献

Freezing effectively preserves meat quality, but the formation of ice crystals during the process can impact tenderness and functionality. Thawing is a critical step, as it can lead to physicochemical changes—such as protein oxidation and further ice crystal growth—that may reduce product quality and consumer appeal. Therefore, the thawing method plays a key role in determining the final quality of frozen meat. This study evaluated the physicochemical and structural characteristics of beef liver frozen at − 18 ± 2 °C for 20 h and thawed using three methods: water immersion thawing (WIT), ultrasonic bath thawing (UBT), and air fryer thawing (AFT). No significant differences in drip loss were observed among the UBT, AFT, and WIT samples (p > 0.05). Color measurements (L*, a*, b*) were significantly higher in raw liver than in AFT and UBT samples (p < 0.05). Compared to raw liver and the WIT method, AF and UB thawing lowered the denaturation temperature, indicating reduced thermal stability. The lowest metmyoglobin (MetMb) content was found in the UBT sample (36.57 ± 0.87%), followed by the AFT sample (41.71 ± 1.29%), suggesting better pigment preservation with UB thawing.

Wall materials are crucial for microcapsule preparation, determining largely microencapsulation properties. Therefore, the interaction among wall materials properties, emulsion stability, and the as-prepared microcapsules properties should be investigated to improve the quality characteristics of microcapsules. In this study, we meticulously investigated the wettability of chitosan–octenyl succinic anhydride (OSA) starch complexes (Chi–OSA), the stability of Nannochloropsis oil (NO) Pickering emulsions stabilised by Chi–OSA, the properties of the NO microcapsules, and the correlation between these factors. Using the Pickering emulsion template, we successfully prepared NO microcapsules after being optimised through response surface methodology. Under optimised conditions (chitosan/OSA-starch mass ratio = 0.8, pH 5.4, 10% oil content), the NO microcapsules achieved a maximum encapsulation efficiency (EE) of 97.66%, with sizes ranging from 0.5 to 2.0 μm. Furthermore, the correlation between the EE of NO microcapsules and the contact angle of Chi–OSA was linear under different pH values (R² = 0.98) while exponential under different chitosan/OSA-starch mass ratios (R² = 0.99). In addition, the as-prepared NO microcapsules showed excellent solubility, storage stability, and antioxidant activity. This study provides theoretical guidance for rational wall material selection and high-quality microcapsule preparation.

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Cinnamon essential oil (CEO) is rich in bioactive compounds that possess antimicrobial and anti-inflammatory properties. However, these compounds are prone to environmental degradation. Encapsulation strategies using citrus pectin (PEC) have emerged as effective methods for protecting, stabilizing, and controlling the release of CEO, thanks to PEC’s emulsifying and ionic gelation capabilities. The objective of this study was to develop and characterize PEC-based beads incorporating CEO. The research aimed to assess their physicochemical and biological properties to evaluate their potential as an oral delivery platform for antimicrobial or anti-inflammatory purposes. The beads were formulated using 3.0% (w/w) PEC and varying concentrations of CEO, with zinc acetate as a crosslinker. The parameters assessed included bead volume, biocompatibility (with erythrocytes and leukocytes), protein adsorption (albumin and total protein), microstructure, elemental composition, FTIR spectra, cinnamaldehyde retention, and antibacterial activity. The incorporation of CEO reduced the bead volume (up to 50.4% with PEC-CEO at 3.0%) and decreased the zinc requirement for crosslinking. Microscopically, the CEO-loaded beads exhibited surface holes (2.80 ± 3.52 μm) and droplets (ranging from 24.8 to 2080 μm), indicating successful encapsulation. While all beads absorbed total protein, higher concentrations of CEO reduced albumin adsorption. Leukocyte damage and hemolysis were observed at CEO concentrations of 2.5% and above. The PEC-CEO formulation at 3.0% remained the highest levels of cinnamaldehyde (1.73 ± 0.20%/mg), while the PEC-CEO formulation at 2.5% demonstrated the strongest antibacterial activity against E. coli, with an inhibition zone of 15.5 ± 0.64 mm. These findings underscore the potential of CEO-loaded pectin beads as a non-conventional therapeutic system for the targeted delivery of bioactive compounds.

Sea buckthorn polyphenols demonstrate significant lipid-lowering potential. Although probiotic fermentation has been shown to enhance the bioactivity of food matrices, its effect on the lipid-lowering function of sea buckthorn juice—particularly regarding the cholesterol esterase inhibition mechanism—remains unclear. Optimized fermentation increased total phenolic and total flavonoid contents to 0.531 mg/g and 0.926 mg/g, respectively, while enhancing antioxidant activity (hydroxyl radical scavenging activity reached 90.13%, metal ion-chelating activity of 69.82%), and increased the inhibition rates against lipase (from 87.13% to 98.13%) and cholesterol esterase (from 94.13% to 98.13%). Among polyphenolic components, conjugated phenols exhibited the strongest inhibitory activity (84.1%). Enzyme inhibition and kinetic studies demonstrated that conjugated phenols effectively inhibit cholesterol esterase. Fermented conjugated phenols exhibited competitive inhibition, whereas unfermented conjugated phenols demonstrated mixed inhibition. Fluorescence quenching experiments confirmed that fermentation-derived conjugated phenols form more stable complexes with cholesterol esterase through dynamic quenching, indicating higher binding affinity. In summary, sequential fermentation serves as an effective bioprocessing strategy. By generating competitive inhibitors of cholesterol esterase, it enhances the lipid-lowering activity of sea buckthorn juice, providing a theoretical basis for developing fermented functional beverages to manage hyperlipidemia.

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This study evaluates the structural, functional, and antioxidant properties of α-tocopherol loaded chitosan and alginate films fabricated as composites and multilayer configurations for potential use in food packaging. Results demonstrated that multilayer films exhibited greater thickness, reduced light transmittance, and higher haze as compared to composite films, with these effects enhanced upon α-tocopherol incorporation. Multilayer films exhibited a substantially lower water vapor transmission rate (WVTR) than composite films. Mechanical testing showed that multilayer films exhibited slightly higher tensile strength than composite films but lower flexibility, while tocopherol addition exerted only minor effects on mechanical behaviour. SEM analysis confirmed dense, compact structures in composite films and distinct bilayer organization in multilayer films, with α-tocopherol incorporation resulting in moderate surface roughness. Antioxidant activity measured via DPPH radical scavenging assay, increased significantly with α-tocopherol incorporation, in multilayer when compared to composite films. Water contact angle analysis revealed improved water resistance in multilayer films (70.67–72.41°) compared to composites (38.11–42.89°), suggesting increased hydrophobicity due to layered architecture. These results demonstrate that multilayer films, offer superior barrier properties, mechanical strength, antioxidant functionality, and water resistance compared to single-layer composites, highlighting their potential as active, eco-friendly packaging solutions.

An intelligent/active packaging film based on cellulose nanofibers (CNF) and gelatin (Gel) loaded with carbon dots (CD) functionalized polyaniline (PANI) composites was developed for freshness monitoring and shelf-life extension of fish meat. The loading of PANI@CD on CNF/Gel film showed a strong antioxidant effect, with DPPH and ABTS radical neutralization rates reaching up to 100%, and increased tensile strength. The synergistic effect of PANI and CD showed an excellent color change from green to blue, caused by sensitivity to ammonia vapor and pH change. It also had high UV blocking ability, blocking 92.5% of UV-A and 96.8% of UV-B. Furthermore, the CNF/Gel/PANI@CD composite film exhibited strong antibacterial potential, significantly inhibiting the growth of E. coli, S. aureus, S. enterica, and L. monocytogenes by 4.2, 8.4, 5.4, and 6.5 Log CFU/mL after 12 h of exposure, respectively. As an intelligent packaging system, the film’s quantitative and qualitative color changes were obvious for monitoring the freshness of fish meat. The results of the active packaging test at 4 °C for 15 days demonstrated that fish packaged with CNF/Gel films incorporated with PANI@CD reduced the quality deterioration rate and extended the shelf life of the packaged food.

Cold plasma (CP) is a promising technology for tailoring plant protein functionality; however, its effect on sunflower protein (SP) gelation has not been fully explored. This study investigated the impact of CP treatment at 1 and 2 kV for 5 to 15 min on the gelation behaviour and structural properties of SP extracted from sunflower meal. Native SP required 20% protein concentration and heating at 90 °C for 1 h to form self-supporting gels. In contrast, CP-treated SP formed gels at 15% concentration and 70 °C within 30 min. The gels retained desirable colour (L = 60.22, a* = 1.48, b* = 15.81) with minimal browning and exhibited a cohesive texture, with hardness increasing with treatment conditions reaching 0.230 N after 15 min at 2 kV. The storage and loss moduli of the SP gels increased with temperature and frequency sweep, with CP-treated SP showing sol transition at 80℃, unlike native SP. The carbonyl content increased to 61.28 nmol/mg, whereas the free sulfhydryl groups decreased to 1.80 µmol/mg after 2 kV for 15 min. Further, intermolecular interactions, particularly disulfide bonds and hydrophobic interactions, were strengthened, while ionic and hydrogen bonds were reduced, thereby contributing to a compact and reinforced gel structure. The structural and rheological modifications induced by reactive species exposing buried hydrophobic groups and oxidizing cysteine residues resulted in improved functional properties, including water-holding capacity, solid content, and freeze–thaw stability. Overall, CP facilitates gel formation under milder conditions, enabling the development of plant-based protein gels with improved texture and functionality for food applications.

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This study investigates the physicochemical, and antioxidant properties of Tanacetum macrophyllum extract and its effects on lamb minced meat during refrigerated storage. The extract exhibited significant antioxidant activity, with high total phenolic and flavonoid contents, confirmed by HPLC analysis revealing abundant p-coumaric acid, ascorbic acid, and quercetin. ICP-MS analysis indicated a rich mineral profile dominated by potassium and calcium. Application of the extract influenced pH and color parameters, enhancing oxidative stability, and preserving meat quality. TBARS values were significantly reduced, indicating inhibited lipid oxidation. Molecular docking revealed strong binding affinity of quercetin to the ATP-binding domain of Pseudomonas aeruginosa DNA Gyrase B, suggesting potential antibacterial activity. Overall, T. macrophyllum extract demonstrates promising natural preservative properties for meat products, contributing to improved shelf life and quality.

This study enhances our comprehension of the molecular composition associated with the detection of sweet taste-by-taste cells TAS1R2/TAS1R3. We apply a recommended adsorption technique and an analytical approach to offer a microscopic insight that elucidates the molecular mechanisms associated with the taste perception of four sweet compounds and the inhibitory impact of lactisole on these compounds. It predicts the total number of molecules associated with each binding site, the quantity of anchors, receptor levels, semi-saturation rates, and adsorption energies. The model’s physicochemical properties enable the assessment of energetic interactions among the four molecules and the TAS1R2/TAS1R3 receptor locations. Additionally, we identified the flavor spectrum by evaluating binding energy values, adhesion energy spectrum (AES), and cavity size spectrum (CSS). This study introduces an innovative method for identifying the flavor spectrum by employing the most suitable model to account for both fixed and fluctuating flavor sensitivities. In the end, the docking analysis featuring four sweet molecules and the taste receptor sites (TAS1R2/TAS1R3) is conducted, highlighting a notable similarity in the mechanism of receptor-ligand complex recognition. As a result, the findings from the docking analysis support the claim that the observed association represent values within the typical retention energy range.