Food Biophysics最新文献

Cherry tomato (Solanum lycopersicum L. var. cerasiforme) is a high-value horticultural product widely consumed due to its desirable sensory qualities and health-promoting properties. However, preserving its quality during freezing remains challenging, particularly because of freezing-induced skin cracking and color degradation. This study evaluated the effects of four freezing methods, multistage freezing (MF), individual quick freezing (IQF), static freezing (SF), and vacuum-assisted IQF (V + IQF), on the quality of cherry tomatoes during six months of storage at − 20 °C. Enzymatic activities of pectin methylesterase (PME), polygalacturonase (PG), and lipoxygenase (LOX), along with physicochemical properties including pH value, titratable acidity, soluble and total solids, lycopene content, color, and skin cracking, were determined. IQF resulted in the highest level of skin cracking, whereas V + IQF significantly reduced cracking; MF and SF showed intermediate effects. Residual PME, PG, and LOX activities were positively correlated with color and lycopene content, while skin cracking was negatively correlated with these attributes. Among the evaluated methods, V + IQF most effectively preserved structural integrity and color stability by reducing skin cracking and improving lycopene retention during long-term storage, demonstrating the potential of vacuum-assisted rapid freezing as an industry-relevant strategy for mitigating freezing-induced quality deterioration in cherry tomatoes.

Dry heating treatment (DHT) is an environmentally friendly technique of starch modification, inducing carbonyl group formation and altering the molecular size distribution of starch. These modified molecules interact differently between each other, with water and glycerol, potentially forming a new polymeric matrix. In this study, potato starch-based films were produced by the casting technique using native and DHT-modified starch treated for 1, 2, and 4 h at 130 °C. Glycerol was used as a plasticizer, and water as the solvent. The films were characterized in terms of morphology, crystallinity, mechanical properties (tensile properties, puncture resistance, and resistance to tear propagation), water vapor permeability, moisture content, solubility in water, and light transmission (UV, visible, and IR wavelengths). The results revealed that DHT-induced molecular rearrangements, affecting the material’s performance in non-monotonic behavior. Starches processed for 1 and 2 h resulted in films with superior mechanical properties, exhibiting increases in Tensile Strength (up to 73%) and Young’s modulus (up to 374%) compared to the native starch film. These films also showed reduced light transmission. Conversely, prolonged treatment (4 h) decreased Tensile Strength and Young’s modulus, and increased light transmission. Furthermore, DHT films exhibited up to 41% reduction in water vapor permeability, as well as decreased moisture content, water solubility, and thickness, while displaying increased crystallinity. These findings highlight DHT as a simple and promising approach for enhancing the performance of potato starch-based films, allowing for diversified properties depending on processing conditions and expanding their potential applications, for example in packaging applications.

Producing stable Pickering emulsions with minimal nanoparticles is difficult, as excessive quantities diminish efficiency, elevate costs, and restrict scalability. In this study, the interfacial characteristics and stability of zein-based Pickering emulsions were improved by the use of natural polysaccharides (PS), fenugreek gum (FG), and xanthan gum (XG). The emulsions were characterized in terms of particle size, ζ potential, contact angle, surface tension, emulsifying activity index (EAI), and emulsion stability index (ESI). Moreover, the optical microscopy images and AFM images were examined. The results indicated that combining FG and XG with zein, especially together (the FG-XG-Z system), greatly enhanced the performance of the emulsion. The system demonstrated the most excellent EAI and ESI values among all formulations, a medium droplet size, a high ζ potential, and a contact angle of about 80°. Also, the lowest droplet size was obtained in the FG-XG-Z complex. These findings demonstrate that FG–XG-Z combinations can significantly improve emulsion stability and offer a practical strategy for heat-resistant emulsified foods with reduced nanoparticle content. Furthermore, it reveals its potential as a clean-label, plant-based strategy for designing suitable stable Pickering emulsions for food, cosmetic, and pharmaceutical applications.

Edible insects are promising nutritional sources, rich in proteins and lipids, but these compounds are prone to degradation during processing and storage. This study investigated the combined effect of blanching and defatting on the stability of Rhynchophorus phoenicis larvae powders stored at 40 °C for 50 days. Three powders were prepared: Non-Blanched and Non-Defatted (Rp NBND), Non-Blanched and Defatted (Rp NBD), and Blanched and Defatted (Rp BD). Biochemical analyses demonstrated that blanching combined with defatting produced the most stable powder with superior nutritional quality. The Rp BD powder showed the highest protein content (56.75 ± 0.47 g/100 g), maintained protein solubility over time, and lacked hydroperoxides, indicators of lipid oxidation. Conversely, Rp NBD displayed the highest moisture content (14.05 ± 0.02 g/100 g), declining protein solubility, and increasing hydroperoxide formation. Electrophoresis (SDS-PAGE) further revealed advanced proteolysis in Rp NBD, unlike the preserved protein integrity in Rp BD. Additionally, 3D excitation-emission fluorescence spectroscopy, coupled with PARAFAC modeling, identified five components linked to natural fluorophores (tocopherol/proteins, NADH/ptérine/pyridoxine, retinol, riboflavin). Their fluorescence evolution depended on treatment and storage. Principal Component Analysis (PCA) showed strong correlations between retinol-associated fluorophores and protein, validating fluorescence spectroscopy as a rapid, non-destructive tool for monitoring insect powder quality.

Ice recrystallization is a major cause of texture and quality deterioration during frozen storage, and antifreeze proteins (AFPs) have attracted attention as potential non-colligative ice-growth inhibitors. This study investigated the combined effects of type I and type III AFPs on ice recrystallization inhibition (IRI), focusing on whether mixing AFPs with different ice-binding specificities enhances their IRI function. AFP solutions were prepared at total protein concentrations ranging from 5 to 50 µg/mL, and the mixing ratios of the two AFPs were systematically varied. Recrystallization rate constants (k) were determined using the Lifshitz–Slyozov–Wagner model. Both AFP types individually reduced k in a concentration-dependent manner; however, no clear synergistic IRI effect was observed in the mixed AFP systems. At low concentrations, the IRI behavior of mixtures corresponded to the concentration-weighted average of the individual AFPs, whereas at higher concentrations the mixtures exhibited antagonistic effects. These findings are consistent with the possibility that the type I and type III AFPs used in this study did not interact cooperatively on the ice surface, likely due to competitive or interfering adsorption. Overall, the findings indicate that effective use of mixed AFP systems may require careful consideration of the binding-surface preferences and spatial adsorption behavior of each AFP.

This study investigates the effectiveness of biodegradable composites of poly(lactic acid)-chitosan (PLA-CHI) combined with UV-A light or mild heat (50 °C) treatments for controlling microbial contamination while maintaining nutrient quality in apple juice. PLA-CHI significantly decreased the microbial load of the bacterium Listeria innocua, achieving reductions of up to 99.9974% (4.59 log reduction) under mild heat and 99.9968% (4.49 log reduction) under UV-A irradiation. Kinetics revealed faster bacterial inactivation when PLA-CHI was present, suggesting an enhanced effect with the other treatments. Scanning electron microscopy showed severe cellular damage, including membrane disruption, cell shrinkage, and leakage of intracellular material, confirming the effectiveness of combined treatments. Surface analyses showed PLA-CHI maintained its structural integrity when exposed to the treatments, though topographical changes increased hydrophilicity and amine group exposure, possibly contributing to greater bactericidal effects. Vitamin C analyses indicated significant photodegradation (~ 33%) following UV-A light exposure, with PLA-CHI slightly accelerating initial degradation but not significantly contributing to overall reduction. Vitamin C was better preserved with mild heat treatments (~ 85% retention), with additional degradation from PLA-CHI being marginal. The integration of PLA-CHI with UV-A or mild heat offers effective antimicrobial activity while preserving nutritional quality. Given its biodegradability, structural stability, antimicrobial effectiveness, and minimal impact on nutrient quality, PLA-CHI presents a feasible and sustainable option for food-packaging applications.

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Chicken meat is a significant source of protein worldwide, and freezing is typically used to extend its shelf life through the supply chain. This research evaluated the impact of repeated freeze–thaw (F–T) cycles and various thawing approaches on the physicochemical, microbiological, volatile, free amino acid (FAA), and sensory quality of Egyptian native chicken (ENC) breast fillets. Fresh control samples (FC) were compared with meat subjected to three F–T cycles and thawed using microwave thawing (MR), chiller thawing (CT), room-temperature thawing (RT), or water thawing (WT). Results showed progressive deterioration across all quality dimensions with increasing F–T cycles. Drip loss, thawing loss, cooking loss, carbonyl content, TBARS, and microbial load showed clear upward trends (p < 0.05), particularly under RT and WT conditions. Conversely, shear force, water-holding capacity, pH, sulfhydryl content, and sensory scores decreased consistently as the number of F–T cycles increased. FAA profiling revealed marked depletion of umami-, sweet-, aromatic-, and bitter-related amino acids, while volatilomics indicated lower levels of lipid-derived aldehydes and ketones associated with oxidative degradation. Sensory assessment further confirmed a gradual loss of appearance, tenderness, aroma, taste, and overall acceptability with repeated F–T cycles. In conclusion, the findings of this study are highly relevant to frozen chicken supply chains, where repeated freeze–thaw events frequently occur during storage, transportation, and retail handling. By systematically integrating physicochemical, oxidative, microbiological, free amino acid, volatile compound, and sensory analyses, this work provides a comprehensive and novel evaluation of freeze–thaw–induced quality deterioration in ENC, a genotype that remains underrepresented in the literature despite its widespread local consumption. The results demonstrate that the thawing method plays a decisive role in modulating quality loss, with MR and CT offering measurable advantages over RT and WT. From an applied perspective, these findings offer practical guidance for processors, retailers, and consumers by identifying thawing strategies that better preserve quality and safety. Scientifically, the study advances understanding of how repeated freeze–thaw cycles interact with muscle structure, oxidative stability, and flavor-related compounds, thereby contributing to improved management practices and future intervention strategies aimed at reducing freeze–thaw–related deterioration in poultry meat.

Pereskia aculeata Miller, commonly known as ora-pro-nobis, is a South American plant widely found in Brazil and classified as a wild plant. Its leaves are rich in bioactive compounds with reported antioxidant, antimicrobial, and anti-inflammatory properties, supporting growing interest in their use as functional ingredients. This study compared conventional hydroethanolic extraction of antioxidant compounds from P. aculeata leaves with a process combining extraction and simultaneous encapsulation, aiming to evaluate differences in stability and bioaccessibility during simulated gastrointestinal digestion. Free and encapsulated extracts (80:20 ethanol: water, v/v) were characterized by Fourier-transform infrared spectroscopy (FTIR), while encapsulated systems were further analyzed by dynamic light scattering (DLS), atomic force microscopy (AFM), and transmission electron microscopy (TEM). Thermal behavior and antiproliferative activity were also evaluated. Total phenolics, flavonoids and antioxidant activity were determined before and after in vitro digestion. Extraction and encapsulation yields were 17.25% and 92.75%, respectively, with the encapsulated extract corresponding to 62% of the free extract. Simulated digestion reduced phenolic content, flavonoid levels, and antioxidant activity in both systems; however, significantly lower losses were observed for the encapsulated extract, indicating improved stability. The apparent divergence between better radical-scavenging stability (ABTS/DPPH) and lower TPC/TFC bioaccessibility in the encapsulated samples likely reflects release- and assay-specific effects. PVP can establish hydrogen-bond and dipolar interactions with phenolics, which may slow their diffusion or release and reduce their immediate availability to react with the Folin-Ciocalteu and aluminum-chloride reagents, lowering measured TPC/TFC in the digesta fraction. In contrast, encapsulation can limit oxidative degradation during digestion, thereby preserving redox-active constituents and sustaining radical-scavenging capacity in ABTS/DPPH assays.

Fucoidan holds promise for use in functional beverages due to its various bioactivities, including anti-inflammatory activity, particularly for elderly individuals. To ensure safe consumption by those with swallowing difficulties, these beverages need to be thickened using agents such as guar gum (GG) at high concentrations (≥ 1.0%). Therefore, this study investigated the influence of saliva on the tribo-rheological properties of 1.0% GG-based fucoidan mixtures, which are closely related to mouthfeel during the oral processing. Additionally, the post-digestive anti-inflammatory activity of fucoidan-GG mixtures was evaluated using the INFOGEST digestion model. All mixtures exhibited pseudoplastic flow behavior, and their apparent viscosity and viscoelastic moduli tended to increase with increasing fucoidan content. The presence of simulated salivary fluid (SSF) reduced shear-thinning behavior and overall rheological characteristics. Specifically, the SSF-mixed samples exhibited shorter relaxation times and more pronounced changes in viscoelastic moduli as a function of the fucoidan-to-GG ratio compared to their original counterparts, suggesting alterations in the nature of intermolecular interactions between the two biopolymers. These changes altered the tribological behavior of the mixtures. A decreasing trend in the friction coefficient was observed with increasing fucoidan content. Additionally, higher fucoidan content led to a delayed transition from the boundary to mixed lubrication regime in both original and SSF-mixed samples, with a more pronounced delay observed in the latter. After digestion, fucoidan-rich mixtures ([fucoidan] ≥ [GG]) significantly suppressed tumor necrosis factor-α production in lipopolysaccharide-stimulated RAW264.7 cells. These findings can provide insights into the design of dysphagia-friendly functional beverages containing fucoidan.

Given the green and tunable nature, ionic liquids have numerous industrial applications as potential alternatives to conventional intense inorganic/volatile organic solvents and costly instruments. In this study, six of 50 mM NH₄Cl, NaCl, KCl, MgCl₂, CaCl₂ or BaCl₂ were employed for extraction of phycobiliprotein-rich protein isolate (PRPI) from Spirulina platensis (S. platensis). It was demonstrated monovalent salts facilitated the extraction PRPI which differed in phycobiliprotein purity but all were found at the higher protein contents than those by divalent salts. In particular, protein subunit composition, structural properties and functionalities were significantly altered by the extraction ionic liquids. For instance, CaCl₂ or MgCl₂ extracted PRPI (PRPI_Ca²⁺ or PRPI_Mg²⁺) exhibited a larger percentage of beta-sheet and disulfide bonds as well as the promoted distribution of tryptophan on protein surface than the counterpart. Subsequently, PRPI_Ca²⁺ or PRPI_Mg²⁺ showed higher surface hydrophobicity/emulsifying stability but lower emulsifying ability. However, the PRPI_Ca²⁺ or PRPI_Mg²⁺, as by TGA analysis, showed lower thermal & storage stability which was largely attributed to the highest phycobiliprotein purity when compared to its counterpart. Correlation analysis indicated that cation-induced changes in protein properties were closely linked to structural alterations, providing valuable data for future development of colloidal food systems.

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