Food Biophysics最新文献

This study explored the influence of high-pressure microfluidization (HPMF) on the structural and functional attributes of apricot kernel protein isolate (AKPI), derived from the deoiled meal of apricot kernels. Single-pass HPMF treatments at 40, 80, 120, and 160 MPa were applied to evaluate pressure-dependent changes in protein morphology, colloidal behavior, molecular structure, and techno-functional properties. HPMF significantly reduced the mean particle size by 78% (from 1362 nm to 259.7 nm) and increased the zeta potential from − 31.2 mV to − 48 mV, enhancing colloidal stability. Scanning electron microscopy (SEM) revealed reduced protein aggregation and a more homogeneous microstructure. Tertiary structural changes assessed via UV–visible and intrinsic fluorescence spectroscopy indicated partial unfolding and exposure of hydrophobic domains up to 80 MPa, with reaggregation observed at higher pressures. At 80 MPa, functional properties were notably enhanced: solubility improved by 26%, emulsifying stability index rose from 67 to 112.5 m²/g, and surface hydrophobicity increased by 30%. Antioxidant potential, measured via DPPH and ABTS assays, increased by 116% and 12%, respectively. In vitro digestibility also improved by 17%, indicating enhanced nutritional bioavailability. Hydrocyanic acid levels in the AKPI were reduced by ~ 88% compared to the meal, suggesting that HPMF can serve as a supportive green detoxification step and can be coupled with the established complementary detoxification treatments. Overall, HPMF particularly at 80 MPa, is a promising non-thermal, biophysical treatment for modulating plant protein structures to improve their functional and nutritional utility in food systems. This work provides mechanistic insights into the structure–function relationship and supports sustainable valorization of plant-based agri-waste.

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Yeast extract is rich in nutrients and is a natural and safe food ingredient. The current process primarily focuses on extracting soluble components from yeast cells, however the utilization of yeast cell wall components remains underdeveloped, leading to the waste of valuable by-products. This study innovatively introduced microfluidization homogenization into the field of yeast extract production and established a high-pressure microfluidization homogenization (HPMH)-assisted yeast autolysis process. It was found that the free amino acid nitrogen content and cell damage index in the treated samples increased by approximately 24.3% and 33.8%, respectively, compared to the high-pressure homogenization (HPH) group; after 42 h of autolysis, the protein, nucleic acid, extracellular protease activity, free amino acid nitrogen of the HPMH group samples increased by about 4.3%, 9.7%, 4.7%, and 10.8% respectively compared with the HPH group. The content of flavor amino acids in the yeast extract sample prepared using this method reached 49.78 mg/g, accounting for 51.6% of the total amino acids, and the proportion of flavor amino acids was about 4.2% points higher than that of the enzymatic hydrolysis group. In brief, HPMH could effectively optimize the preparation process of yeast extract and its by-products.

The increasing application of cocoa butter alternatives in confectionery products requires a deep understanding of their crystallization behavior in order to maintain and promote desirable quality attributes. Through the combination of X-ray diffraction, microscopic, and thermal analysis techniques, this study explored the polymorphic, microstructural, and melting properties of cocoa butter and shea butter stearin blends with varying compositions. Results showed a more complex polymorphic behavior in blends than in the pure fats, with the coexistence of β′-2L and β′-3L forms, whose occurrence was strongly influenced by both the cocoa butter/shea stearin ratio and the thermal treatments applied. The solid fat content analysis evidenced, at all the analyzed samples, an abrupt falling typical for CB-like melting profile, which occurred between 30 and 35 °C in CB, and shifted to above 35 °C in ShS. Blends with increasing amounts of shea stearin showed a higher thermal resistance, a smoother thermal profile and a delayed β-phase development under isothermal conditions. Moreover, moderate variations of the composition modified the microstructure of the blends, which suggests potential impacts on the texture and sensory perception of products including this fat system.

Optimizing post-harvest drying methods for medicinal plants plays a crucial role in agricultural management and development by enhancing product quality, reducing post-harvest losses, and supporting value-added production strategies through the preservation of active compounds, prevention of spoilage, and extension of shelf life. This study, conducted using a completely randomized factorial design with three replications, evaluated the effects of five drying methods—shade drying at 25 ± 3 °C, oven drying at 55 °C, vacuum oven at 55 °C, microwave at 600 W, and infrared at 0.3 W—and three storage durations (1, 75, and 150 days) on the quality characteristics and secondary metabolites of squirting cucumber (Ecballium elaterium) fruit. Among the drying methods evaluated, infrared drying at 0.3 W most effectively preserved key bioactive compounds, including chlorophyll a (11.2 mg/g), chlorophyll b (3.8 mg/g), carotenoids (2.1 mg/g), and total phenolic content (68 mg GAE/g DW). The greatest total color change (ΔE = 45.2) was observed in shade-dried samples after 150 days of storage, whereas the minimal color change (ΔE = 18.5) was recorded in fresh fruit. The highest total color change occurred in shade-dried samples after 150 days, while the least change was observed in fresh fruit, followed by infrared drying (0.3 W) on day one. The chroma and whiteness indices were highest in fresh fruit and infrared-dried samples, while the lowest values were found in shade-dried samples. Faster drying methods, like infrared, better preserved color quality, while slower methods, such as shade drying, led to greater color changes due to prolonged exposure to oxidation.

Karanda (Carissa carandas Linn.) fruit extract (KE) is recognized for its antimicrobial properties and richness in bioactive compounds. This study investigated the effectiveness of KE at different maturity stages, with or without chitosan coating, in preserving the quality of cherry tomatoes during refrigerated storage. Extracts were obtained by hot-water extraction (90 °C, 1 h) or ethanol extraction (50% or 95%, 24 h). Ripe fruit extracted with 50% ethanol exhibited the highest total phenolic content, antioxidant capacity, and inhibitory activity against foodborne pathogens. Both KE (5%) and KE combined with 0.25% chitosan (KEC) effectively suppressed Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli. KEC and chitosan coatings helped maintain visual quality (reduced shrinkage), weight loss, firmness, acidity, and soluble solids. Meanwhile, KEC-treated fruit retained higher levels of ascorbic acid, phenolics, and antioxidant capacity compared to other treatments. In addition, KEC and KE enhanced antioxidant enzyme activity and lowered H₂O₂ accumulation, while significantly reducing total bacterial, yeast, and mold counts during storage. Principal Component Analysis (PCA) confirmed that KEC was strongly correlated with improved antioxidant status and reduced oxidative stress. Overall, KE- and KEC-based coatings show promise for commercial postharvest handling to enhance microbial safety, nutritional quality, and shelf life of cherry tomatoes and other perishable fruits.

In order to investigate the molecular properties of molasses, ¹H spin-lattice and spin-spin relaxation experiments were performed at 18.56 MHz on a series of beet molasses (including their mixtures) and a series of cane molasses of different types and origins. The extensive data sets were thoroughly analyzed in search of characteristic relaxation features (markers) of the molasses. This revealed general relaxation characteristics of molasses, such as a linear trend of increasing relaxation rates with Brix degree (influenced to some extent by the presence of various additives, some of which are paramagnetic). In parallel, specific relaxation features, such as the bi-exponentiality of the spin-spin relaxation processes for some molasses, have been identified. The quantitative description and comparison of the relaxation parameters shows that although the type and origin of molasses cannot be unambiguously identified on the basis of the relaxation rates alone, the overall relaxation scenario described by a set of well-defined quantities provides a valuable insight for quality and authenticity testing of molasses. The NMR relaxation studies reveal differences between molasses at the level of molecular motion and arrangements that are not accessible by other methods.

Flavonoids are bioactive polyphenolic compounds that play essential roles in normal physiological processes in both plants and animals. Due to their potent antioxidant, anti-inflammatory, antimutagenic, and anticarcinogenic properties, flavonoids have Received significant scientific attention as potential therapeutic agents in the 21st century. The present study highlighted their potential in disease management by elaborating their antimicrobial, antioxidant, anticancer, molecular docking, and enzymatic Regulatory properties. Among the flavonoids examined, diosmetin showed a strong inhibitory effect with Ki values at 0.35 ± 0.12 µM, 1.18 ± 0.38 µM, and 0.26 ± 0.01 µM for Carbonic anhydrase (hCAI, hCAII), and Acetylcholinesterase (AChE), respectively. Since these enzymes play critical roles in diseases such as Alzheimer’s, glaucoma, and cancer, flavonoid based enzyme modulation may offer novel therapeutic strategies. However, bioavailability and metabolic stability remain important challenge for clinical applications. In addition to their enzymatic effects, flavonoids have demonstrated potent antimicrobial activity, especially against multidrug resistant pathogens, suggesting their potential role in developing next generation antibiotics. Moreover, their strong antioxidant properties offer a promising approach to the management of chronic diseases, including cancer and neurodegenerative disorders, which are closely linked to oxidative stress. The compounds induced cell death with shown anticancer activity in a dose dependent manner on SH-SY5Y neuroblastoma cells.

Modified starch (MS), wheat flour (WF), and xanthan gum (XG) are common rheological modifiers used to stabilize oyster sauce and prevent sedimentation. A downside of these thickeners is that they impart poor pourability, an issue that is exacerbated at lower temperatures. This study examines the impact of different thickeners on oyster sauce rheology to address consumer concerns regarding temperature sensitivity and flow control. Rheological tests showed that MS alone resulted in the lowest yield stress (26.18 Pa at 5 °C), while XG significantly increased it (58.81 Pa). Although XG reduced the temperature sensitivity of viscosity, it had limited effects on yield stress. Thixotropy tests indicated that WF introduced rheopectic behavior with viscosity recovery (%η_r) exceeding 100% at 5 °C, whereas MS and XG exhibited thixotropic behavior. Nonlinear viscoelastic analysis revealed that MS + XG + WF reduced the Payne effect to 12.57%, compared to 76.25% for MS alone, improving structural stability. Overall, combining thickeners enhanced consistency, reducing temperature–induced variations and pouring inconsistencies. Yield stress and thixotropy were found to be more critical than viscosity in characterizing the ‘pouring problem.’ These findings offer insights into optimizing oyster sauce formulations for improved usability and stability.

This study extracted characterized, and incorporated jabuticaba (Plinia sp.) peel extract, within avocado seed starch fibers via electrospinning and subsequently added to yogurt. The extract was analyzed for color, anthocyanin content, phenolic compound concentration, and antioxidant activity. Different avocado seed starch fiber concentrations were examined for morphology, size, infrared spectroscopic profile, loading efficiency, and antioxidant activity. In vitro assays determined the encapsulated compounds’ bioaccessibility. The free extract exhibited significant anthocyanin and phenolic compound contents, as well as high antioxidant capacity. The fibers demonstrated uniform morphology, small diameters, efficient compound loading, thermal resistance up to 300 °C, antioxidant activity ranging from 21.28 to 67.33% (2,2’-azino-bis (3-ethylbenzothiazoline) 6-sulfonic acid) and phenolic compound content of 206–260 mg of gallic acid equivalents. Encapsulation effectively preserved these bioactive compounds within the food matrix and enhanced their bioaccessibility by approximately 23%, preserving and improving both antioxidant activity and phenolic content. These results underscore that encapsulated bioactive compounds can improve the nutritional properties of yogurt, offering greater health benefits.

To solve the problem of post-harvest food freshness and reduce the pollution of synthetic plastics, an environmentally friendly cling film was developed by incorporating alizarin (AZ) and carbon dots (CDs) into a polyvinyl alcohol/sodium alginate (PVA/SA) matrix. The introduction of AZ and CDs improved the microstructure of the film and enhanced the mechanical strength and barrier properties of the film. The antibacterial test showed that the PVA/SA/AZ/CDs composites had superior antibacterial properties against Escherichia coli (12.1 mm) and Staphylococcus aureus (12.3 mm), which were better than those films doped with AZ or CD only. The weight loss of the composite film within 13 days was 29.3% lower than that of the control group as verified by the freshness preservation experiment of cherry tomatoes, indicating that the film effectively inhibited transpiration and respiration of cherry tomatoes, and therefore slowed down the conversion of sugars (the peak of TSS was delayed for 3 days) and the concentration of titratable acid (the TA content was 0.18 mol/L higher than that of the control group), and extended the shelf-life of cherry tomatoes. And the biocompatibility of the film was verified using pea germination experiment. This study provides a reference for the development of next-generation green preservation materials.