Food Biophysics最新文献

Glucansucrases catalyze the production of α-glucans using sucrose as substrate with distinct physicochemical characteristics originates from mainly the type of linkages, degree of branching and molecular mass. New forms of α-glucans can be produced by applying specific mutations to glucansucrases. In this study, a single and double mutation at Leu⁹³³ and Leu⁹³⁵ sites of glucansucrase E81 was applied and L933I and L933I-L935F sites modified glucansucrase was obtained. Structural characterisation of bioengineered α-glucans revealed that ratio of (1 → 3):(1 → 6) linked α-Glc units altered at L933I whereas no (1 → 3)-linked α-Glc units were presented for L933I-L935F modified glucansucrase detected by NMR analysis. Both bioengineered α-glucans had lower molecular weights in comparison to glucan E81 detected by GPC analysis. TGA and DSC analysis were applied to detect the thermal profiles of bioengineered α-glucans whereas FTIR and XRD analysis were applied to determine the alterations in the structural and physical nature of the bioengineered α-glucans, respectively. Finally, SEM and AFM analysis were applied to explore the morphological modifications of the bioengineered α-glucans. This study provides a better understanding for the potential role of final glucan structures on their physicochemical characteristics. Keywords: glucansucrase; carbohydrate engineering; mutation.

To improve the lipophilicity and antioxidant potential of ferulic acid (FA), four novel 1-O-alkylglyceryl ferulates (C₈Gly₁F, C₁₂Gly₁F, C₁₆Gly₁F, and C_18:1Gly₁F) were synthesized via Novozym 435-catalyzed transesterification in n-hexane at 65 °C, achieving high conversion rates and good enzyme reusability. Crystallinity and thermal properties, analyzed by polarized light microscopy and DSC, revealed that C₁₂Gly₁F exhibited optimal crystallinity, while C_18:1Gly₁F, due to its unsaturated alkyl chain, was predominantly amorphous, suggesting enhanced solubility. Antioxidant assays (DPPH and ABTS) demonstrated higher radical scavenging activity compared to ethyl ferulate, with C_18:1Gly₁F showing the best performance. Density functional theory calculations revealed its high electron affinity, electrophilicity, and a delocalized HOMO–LUMO distribution, supporting its proposed antioxidant mechanism. These findings highlight the potential of 1-O-alkylglyceryl ferulates as effective lipophilic antioxidants for use in functional foods and lipid-based delivery systems.

Metabolic dysfunction-associated steatotic liver disease (MASLD) has been rising in prevalence. As an essential trace element, copper plays a crucial role in iron metabolism, lipid peroxidation, and fatty acid synthesis. Copper deficiency exacerbates MASLD progression by disrupting these metabolic processes. The processed black ginseng (BG) has abundant rare ginsenosides, such as Rg3 and Rk1, which have shown potential in alleviating hepatic steatosis and inflammation. In this study, the MASLD model was established in middle-aged mice by feeding a copper-deficient diet (< 0.1 mg/kg Cu) combined with a high-sugar solution. By integrating multi-omics approaches, including serum metabolomics, hepatic lipidomics, gut microbiome analysis, and molecular docking, we systematically investigated the therapeutic effects and underlying mechanisms of BG on MASLD. The results demonstrated that BG treatment significantly improved body weight regulation, reduced serum ALT and AST levels, corrected lipid abnormalities, and alleviated hepatic lipid accumulation. Multi-omics analyses revealed that BG exerted its effects primarily by modulating multiple metabolic pathways, including arachidonic acid, linoleic acid, retinol, and sphingolipid metabolism, thereby restoring liver-serum metabolic homeostasis. Moreover, BG improved gut microbiota composition by increasing the abundance of beneficial bacteria such as Akkermansia and Faecalibaculum while reducing the levels of pathogenic Proteobacteria. Molecular docking confirmed that BG-derived ginsenosides exhibited high binding affinity to key targets in arachidonic acid metabolism, including COX-2, 5-LOX, and PLA2. In conclusion, BG exerted hepatoprotective effects against MASLD by targeting multiple pathways and restoring gut-liver axis homeostasis. These findings provide theoretical and experimental support for the application of BG in MASLD intervention.

Graphical Abstract

This study adapted traditional Southeast Asian rice–shrimp fermentation methods to prepare Penaeus vannamei fermented with rice (FPV-R), focusing on unraveling the novel interplay between microbial community dynamics and flavor development. The synergistic interaction between umami amino acids and flavor nucleotides was strongest on day 9 (C9), with the equivalent umami concentration (EUC) reaching 25.85 g MSG per 100 g FPV-R. Headspace solid-phase microextraction-gas chromatography mass spectrometry (HS-SPME-GC-MS) identified 12 key flavor compounds (ROAV ≥ 1.0), with aldehydes and alcohols as the major aroma determinants. Microbial community analysis revealed Staphylococcus, Flavobacterium, Brumimicrobium, and Arcobacter as the dominant genera, closely associated with flavor formation in FPV-R. The abundance of Staphylococcus increased significantly during fermentation, its excessive dominance on day 12 (C12) not only undermines the balance of the overall flavor profile but may also be a primary factor linked to the production of undesirable flavor compounds, including dimethyl sulfide, hexanoic acid, and naphthalene. Collectively, the sample at day 9 (C9) exhibited the most balanced and favorable flavor profile. These findings fill the knowledge gap in understanding microbe-flavor interactions in traditional shrimp-rice mixed fermented products and provide a theoretical basis for the improvement of traditional fermented shrimp products and the development of fermentation-specific bacterial starters.

This work demonstrates a sustainable strategy for stabilizing and functionalizing ginger essential oil (GEO) Pickering nanoemulsions using cellulose nanocrystals (CNCs) derived from microcrystalline cellulose via a green deep eutectic solvent (DES) system. The CNCs were isolated with a high yield (95.87%) and exhibited notable crystallinity (52.74%), nanoscale morphology (< 50 nm), and thermal stability. CNC-GEO nanoemulsions were formulated at 0.3–2.0 wt% and systematically characterized for interfacial interactions, droplet stability, release kinetics, and functional properties. The 1.0 wt% CNC system achieved the most balanced performance, with a small droplet size (~ 34.7 nm), high zeta potential (–34.8 mV), low polydispersity, and > 99.7% encapsulation efficiency, as well as superior resistance to centrifugal, thermal, and freeze–thaw stress. Release studies confirmed that CNC concentration governed GEO availability: higher CNC loadings enhanced network density but slowed diffusion and reduced antioxidant efficiency. At the same time, moderate levels promoted bioactive release and stronger radical scavenging. Antibacterial assays confirmed selective inhibition, with Gram-positive S. aureus being more susceptible than Gram-negative E. coli, reflecting a distinct envelope structure. SEM and EDX analyses further revealed that CNC-GEO emulsions caused oxidative damage, membrane disruption, and elemental leakage. Collectively, these results highlight CNCs as multifunctional, food-grade stabilizers that couple structural stability with tunable bioactivity, offering a scalable route to polymer-free nanoemulsions for food preservation, nutraceutical, and pharmaceutical applications.

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.

Graphical Abstract

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.

Graphical Abstract

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.