Food Biophysics最新文献

Streptococcus mutans (S. mutans) is a keystone pathogen in dental caries pathogenesis, with biofilm formation primarily dependent on sucrose-derived glucans. Pu’er tea, a fermented tea originating from Yunnan Province, China, harbors diverse microbial communities. In the study, Staphylococcus sp. XK3H5 isolated from Pu’er tea showed strong antagonistic activity against S. mutans UA159. Strain XK3H5 exhibited probiotic potential including lysozyme resistance, superior auto-aggregation and co-aggregation capacity with S. mutans, hydroxyapatite adhesion capacity and significant inhibition of S. mutans biofilm biomass. Safety assessment confirmed that Staphylococcus sp. XK3H5 is a non-hemolytic strain, with an inability to produce biogenic amine and susceptibility to six clinical antibiotics. Cell-free supernatant (CFS) of Staphylococcus sp. XK3H5 suppressed S. mutans biofilm biomass. Mechanistic analysis indicated that strain XK3H5 CFS significantly impaired sucrose metabolism in S. mutans, reducing water-insoluble exopolysaccharide production. Notably, qPCR analysis demonstrated that the expression of gtfB, gtfC, gtfD, and ftf genes was down-regulated in S. mutans treated with XK3H5 CFS, which is critical for glucan-mediated biofilm maturation and bacterial adhesion. Our study demonstrated Staphylococcus sp. XK3H5 can inhibit S. mutans biofilm formation, offering an alternative way as a potential oral probiotic.

In this study, we investigated the physical, rheological and morphological properties of agglomerated xanthan gum (XG), carboxymethyl cellulose (CMC), guar gum (GG) and locust bean gum (LBG) powders used as food thickeners for patients with dysphagia. Compared to their non-agglomerated counterparts, gum powders agglomerated with maltodextrin (MD) as an excipient by using a fluidised-bed granulator exhibited larger, more porous and irregularly shaped structures, resulting in improvements in powder flowability and cohesiveness. In particular, agglomerated CMC had a significantly larger particle size and improved porosity compared to the other gum agglomerates. Although the rheological properties of the agglomerates strongly depended on the gum type, all of them exhibited shear-thinning behaviour, along with an increase in consistency index, apparent viscosity and viscoelastic modulus values at higher concentrations. In addition, agglomerated CMC, GG and LBG exhibited time-independent flow behaviour at a concentration of 1 or 2% in distilled water but anti-thixotropic flow behaviour at 3%. In contrast, agglomerated XG displayed time-independent flow behaviour at 1% and mixed time-dependent flow behaviour at 2 or 3%. These findings suggest that the gum type notably influences the physical, rheological and morphological characteristics of agglomerated gum powders.

As a nutritious marine organism with considerable medicinal value, the sea cucumber faces several challenges in the production of its peptide products, including difficulties in targeted enzymatic hydrolysis, a strong fishy odor, and poor product stability. This study utilized Russian polar sea cucumber as the raw material and successfully prepared sea cucumber peptides through stepwise hydrolysis using neutral protease and papain, optimizing the hydrolysis conditions in the process. Additionally, by screening probiotic strains and optimizing fermentation conditions, we effectively reduced the fishy odor of the sea cucumber peptides while imparting floral and fruity aromas along with a sense of fermented freshness. Analysis of the processed sea cucumber peptide powder demonstrated high protein content and excellent properties in water absorption, oil absorption, and emulsification. Furthermore, our research indicated that sea cucumber peptide powder processed using freeze-drying technology exhibited superior microstructural characteristics compared to that processed by spray drying technology. This study establishes a solid scientific foundation for the industrial production of sea cucumber peptides.

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This study employs thermosonication (combination of ultrasound and thermal treatment) for the pasteurization of apple juice. Thermosonication can arrest the enzymes peroxidase (POD) and polyphenol oxidase (PPO), which cause enzymatic browning in apple juice. The goal is to demonstrate that thermosonication results in faster deactivation of POD and PPO enzymes compared to thermal treatment. Additionally, the study aims to optimize the thermosonication parameters to achieve the minimum processing time while ensuring that 99.9% of the enzymes are inactivated. For this purpose, a 2-D axisymmetric numerical model was developed to simulate the pasteurization process using thermosonication. Surrogate-based optimization was used to identify the optimal thermosonication parameters (processing time, probe diameter, probe immersion depth, and beaker shape) that minimize processing time and achieve the target enzyme residual activity of 0.1% in POD and PPO. The results show that thermosonication at 65 °C for 180 s in a cylindrical beaker improves POD and PPO inactivation by 3.33% and 13.79%, respectively, compared to thermal treatment. Further optimization revealed that a minimum processing time of 658 s at 65 °C is achievable in a conical beaker with a probe diameter of 19 mm and immersion depth of 45%, reducing processing time compared to cylindrical and hemispherical beakers.

Cottonseed oil is one of the most widely used edible oils in the World because of its neutral flavor and high smoke point. This oil is found in everything from salad dressings and baked goods to frying oils in restaurants. In this study, pretreatment of enzymatic aqueous extraction (PEAE) was firstly and successfully adopted with ultrasound and homogenization-assisted (UHA)-Ethyl acetate aimining to improve the recovery of cottonseed oil. This work also investigated whether a two-step statistical optimization approach, combining Plackett-Burman Design (PBD) and Central Composite Design (CCD), could be effectively employed to select significant factors, evaluate their interactions, and optimize the extraction conditions. Based on initial tests, an enzyme combination of Alcalase 2.4 L and Cellulast 1.5 L (1:1) was chosen for enzymatic hydrolysis. PBD results identified enzyme concentration and water-to-seed ratio as the most significant factors, which were further optimized by CCD, while homogenization was consistently applied to all experimental runs. Meanwhile, optimal conditions were determined as 2.5% enzyme concentration and a 3:1 mL/g water-to-seed ratio, yielding 82.41% oil recovery, 7.75% free fatty acid content (FFA), and 70.42% radical scavenging activity (RSA). Pearson’s correlation analysis found robust negative correlations between RSA and water-to-seed ratio (r = − 0.940), as well as between FFA and TPC (r = – 0.851), emphasizing noteworthy interrelationships among processing parameters and oil quality. The results highlight, for the first time, the promising potential of the PEAE-UHA-Ethyl Acetate approach in a statistically optimized framework, as a novel, sustainable, and high-efficiency technique for generating cottonseed oil with satisfactory quality metrics.

The growing demand for biodegradable and intelligent packaging materials has accelerated efforts to valorize agro-industrial byproducts. Wine industry byproducts (WB) are rich in anthocyanins, natural pigments with halochromic properties that can be exploited as freshness indicators. This study aimed to develop pH-sensitive PLA-based films by incorporating anthocyanin-rich WB extracts. As part of the valorization process, the drying kinetics of WB were also evaluated as a necessary pretreatment to find out the right drying technique and so facilitate anthocyanin recovery. Anthocyanin extracts (AE) were then incorporated into PLA matrice (10–70%) using solution casting, and the resulting films were characterized for mechanical, thermal, optical, and pH-responsive properties. The results showed that freeze-drying preserved higher anthocyanin activity than microwave drying. Mechanical strength decreased with AE addition, from 76 MPa in neat PLA to 7 MPa at 70% AE, while films with 10% AE retained 60 MPa. Opacity increased from 1.37 to 11.32, enhancing halochromic visibility. Thermal stability decreased slightly, with T_g shifting from 60 °C to 54 °C and T_m from 156 °C to ~ 150 °C. Importantly, the composite films exhibited distinct color changes with pH values, with more pronounced shifts under alkaline conditions. These findings highlight the feasibility of upcycling WB into PLA-based halochromic films, offering a sustainable alternative to conventional plastics for intelligent food packaging applications.

To address the issues of low recycling value for defective coffee beans and coffee grounds, and their environmental pollution. In this study, coffee oil was extracted from dark-roasted Arabica coffee beans, and its refining process was optimized through acid-catalyzed degumming and alkali neutralization. The effects of each processing stage on the physicochemical properties, fatty acid profile, and volatile compound composition of the coffee oil were systematically investigated. The results indicated that through single-factor and orthogonal experiments, the optimal parameters for the acid-catalyzed degumming process were as follows: citric acid solution concentration of 60.0%, citric acid dosage of 0.25%, water addition of 2.0%, degumming temperature of 45 °C, and hydration time of 40 min. Under the aforementioned conditions, the degummed oil was prepared and subsequently subjected to alkali refining for deacidification. Through single-factor and response surface experiments, the optimal process parameters for alkali refining deacidification were determined as follows: sodium hydroxide solution concentration 10.0%, excess alkali amount 0.20%, refining temperature 50 °C, and reaction time 20 min. The physicochemical properties of the coffee oil were analyzed before and after refining. The results showed significant reductions in acid value (94.7%), peroxide value (36.6%), and moisture/volatile matter content (78.74%). While the fatty acid composition and volatile compound profiles remained largely consistent, minor quantitative variations were observed.

This study investigated the effects of fucoidan (1–3 wt%) on the rheological and tribological properties of milk protein isolate (MPI, 15 wt%). With increasing fucoidan concentration, particle sizes of MPI–fucoidan mixtures significantly increased, and their ζ-potentials gradually decreased. Fourier transform infrared spectroscopy confirmed the presence of intermolecular interactions between MPI and fucoidan, while scanning electron microscopy revealed that these interactions promoted the formation of a more uniform, compact, and robust three-dimensional network structure. The MPI-fucoidan mixtures exhibited significantly lower flow behavior indices (0.44–0.48) and higher consistency indices (7.24–10.1 Pa∙sⁿ) and apparent viscosity at 100 s⁻¹ (0.67–0.75 Pa∙s) compared to that without fucoidan (0.52, 1.19 Pa∙sⁿ, and 0.21 Pa∙s, respectively). Viscoelastic properties also significantly improved with higher fucoidan concentrations, with the elastic modulus showing a more pronounced increase than the viscous modulus. While MPI alone exhibited time-independent flow behavior, MPI-fucoidan mixtures displayed thixotropic behavior. All samples showed friction curves with five distinct regimes, and both maximum and minimum friction coefficients decreased as fucoidan concentration increased, indicating improved lubrication. These findings suggest that fucoidan can enhance the tribo-rheological performance of MPI, offering potential applications in food formulation.

Bioactive compounds naturally present in plants are vital in promoting health and preventing chronic diseases. Among these, sulforaphane has received considerable attention due to its well-documented anticancer, antimicrobial, and anti-inflammatory properties. In this study, sulforaphane (> 90% purity) was microencapsulated via the spray chilling technique to mask its undesirable taste and odour, enhance its bioaccessibility, and improve its stability. The spray chilling process was optimized using a Central Composite Rotatable Design (CCRD), with the optimal conditions identified as 0.68% sulforaphane–cottonseed oil concentration, 92.03% palm oil concentration, and an air inlet temperature of 17.16 °C. Under these conditions, microcapsules were produced with high encapsulation efficiency (84.56%), solubility (9.46%), and in vitro intestinal release (63.45%), while maintaining a low in vitro gastric release (17.48%). These findings underscore the potential of the spray chilling technique as an effective strategy for delivering sulforaphane in functional food and nutraceutical applications. Additionally, storage stability and release/degradation kinetics of sulforaphane extract, purified sulforaphane, and microencapsulated forms via ionic gelation and spray chilling were investigated under controlled conditions. First-order kinetic models were applied to calculate degradation rate constants (k), half-life values (t₁/₂), and coefficients of determination (R²), providing quantitative insights into the degradation behaviour of each sulforaphane form. The results showed that microencapsulation not only protected sulforaphane from environmental degradation but also enabled controlled release, particularly under high-temperature and variable pH conditions, by slowing the degradation kinetics.