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Chitosan/polyvinylpyrrolidone composite films containing hydroalcoholic Ziziphora clinopodioides extract were developed and evaluated for their potential use as wound dressings. The physical and chemical properties of the films were extensively explored, including swelling capacity, mechanical properties, antimicrobial activity, and microstructural characteristics. The results showed that the addition of Ziziphora extract significantly increased the swelling capacity of the films by 561.24% to 1175% (p < 0.05). While tensile strength and Young's modulus were enhanced, elongation at the breaking point decreased with increasing volume percentages of Ziziphora extract. Variance analysis indicated no statistically significant effect on the tensile properties of the films with varying Ziziphora extract content (p < 0.05). Furthermore, films incorporated with Ziziphora extract demonstrated antimicrobial properties. Scanning electron microscopy (SEM) analysis revealed that samples lacking Ziziphora extract had a smooth surface, while those containing the extract displayed a rough texture that may potentially accelerate the wound healing process. [ABSTRACT FROM AUTHOR]

In this study, we engineered a sub-70 nm nanocomposite of ZnO/Zn2TiO4 using a low-temperature solution-phase method with titanium isopropoxide and zinc acetate as precursors, and isopropyl alcohol and water as solvents. The investigation focused on nanocomposite growth by varying precursor and surfactant concentrations and their efficiency within different pH ranges. All three ZnO/Zn2TiO4 nanocomposites exhibited hexagonal wurtzite ZnO and Zn2TiO4 structures. The crystallite size in these nanocomposites ranged from 39.50 nm to 62.67 nm for ZnO and 21.24 nm to 26.15 nm for Zn2TiO4. Morphological observations using FESEM revealed the formation of dispersed cotton packet-like nanocomposites with sizes ranging from 18 to 350 nm. FTIR analysis showed peaks indicative of Ti–O and Zn–O bond formation, and EDX spectrum confirmed the presence of Ti, O, and Zn. UV spectrums and photocatalytic investigations confirmed the successful formation of ZnO/Zn2TiO4 nanocomposites with notable photocatalytic degradation efficiency for methylene blue dye under various conditions. These findings suggest the potential applicability of the synthesized nanocomposites for environmental pollutant degradation. [ABSTRACT FROM AUTHOR]

Incorporation of antioxidants, such as phenolic compounds into edible oils has limitations such as rapid release of phenolic compounds, low solubility, low penetration, low accessibility, and rapid degradation by environmental compounds. To solve this problem, the nano‐encapsulation process is offering promising opportunities. In this research, for the first time, the phenolic extract of Mentha aquatica was nano‐encapsulated in nano‐emulsions coated with chitosan, Lepidium perfoliatum gum (LPG), and complex of chitosan and LPG (CCL) (1:1 ratio). Based on various tests (particle size measurement, ζ‐potential, polydispersity index, encapsulation efficiency index, and intensity curve), the LPG coating was the most optimum option for nano‐encapsulation compared to the other coatings. Thus, the LPG‐assisted nano‐encapsulated phenolic extract of M. aquatica was used to improve the oxidative stability of canola oil at three concentrations (100, 200, and 300 ppm). The results of peroxide value and anisidine index tests (as initial and secondary oxidation indicators, respectively) showed that the nano‐encapsulation improved the antioxidant effect of M. aquatica when compared with free extract in canola oil. In a comparative approach, the best sample was obtained from the LPG‐assisted nano‐encapsulated extract (200 ppm) due to the release of more phenolic compounds. The findings from this study showcase how nano‐encapsulation enhances the efficacy of antioxidants in edible oils. [ABSTRACT FROM AUTHOR]

Industrial processes do not often deal with a pure fluid. Impurities can affect physical properties of gas-liquid systems, resulting in change of gas bubbles velocity. Purpose of the study was to determine drag coefficient of a bubble rising through a contaminated fluid. As well as, a comparison was done between conditions of a free rising bubble and a rising bubble in wall-bounded flow. Thus, the behavior of a single air bubble rises in aqueous rhamnolipid solutions within two columns with different dimensions was studied experimentally. The experiments were conducted at high Reynolds numbers compared to other researches. The results revealed that effect of the surfactant in wall-bounded flow was much less than free flow whereas bubble terminal velocity was close to the one in a pure fluid and independent of concentration. Moreover, terminal velocity of the free rising bubble decreased as the solution concentration increased for the one less than critical micelle concentration. After that, it kept constant. Furthermore, resulted drag coefficient did not change significantly in different biosurfactant concentrations. The results showed that in high Reynolds number, drag coefficient was a function of Eötvös number and independent of Reynolds and Morton numbers. Consequently, two empirical correlations were presented to predict the terminal velocity and drag coefficient based on surface tension and Eötvös number, respectively. [ABSTRACT FROM AUTHOR]

Rhamnolipid (RL) is a surfactant biosynthesized by Pseudomonas aeruginosa strains. The RL feasibility as a high-efficient emulsifier in increasing the physical stability of sesame oil (SO)-based beverage emulsions formed by the ultrasound-assisted emulsification process was studied. The concentration of SO (2.02%–6.98% wt/wt), and RL (0.49%–1.51% wt/wt) was adequately optimized based on the analysis of physical stability, turbidity loss rate (TLR), size index, density, and viscosity characteristics using the central composite rotatable design-response surface methodology. The overall optimum region to attain the highest stability (92.64%), viscosity ratio (0.338), and density (1.017 g/cm³), and the lowest TLR (0.216 Ǻ/day) and size index (0.240) based on the adequate second-order polynomial models (R² = 0.956–0.991) was obtained at the combined level of 2.75% (wt/wt) SO and 0.662% (wt/wt) RL. No significant difference between the observed and predicted values fitted to secondorder polynomial models was found. RL as an efficient biosurfactant can stabilize food-grade emulsion systems. [ABSTRACT FROM AUTHOR]

A potent biosurfactant-producing bacterial strain isolated from spoiled apples was identified by 16S rRNA asPseudomonas aeruginosaMA01. Compositional analysis revealed that the extracted biosurfactant was composed of high percentages of lipid (66%, w/w) and carbohydrate (32%, w/w). The surface tension of pure water decreased gradually with increasing biosurfactant concentration to 32.5 mN m−1with critical micelle concentration (CMC) value of 10.1 mg L−1. The Fourier transform infrared spectrum of extracted biosurfactant confirmed the glycolipid nature of this natural product. Response surface methodology (RSM) was employed to optimize the biosynthesis medium for the production of MA01 biosurfactant. Nineteen carbon sources and 11 nitrogen sources were examined, with soybean oil and sodium nitrate being the most effective carbon and nitrogen sources on biosurfactant production, respectively. Among the organic nitrogen sources examined, yeast extract was necessary as a complementary nitrogen source for high production yield. Biosurfactant production at the optimum value of fermentation processing factor (15.68 g/L) was 29.5% higher than the biosurfactant concentration obtained before the RSM optimization (12.1 g/L). A central composite design algorithm was used to optimize the levels of key medium components, and it was concluded that two stages of optimization using RSM could increase biosurfactant production by 1.46 times, as compared to the values obtained before optimization. [ABSTRACT FROM AUTHOR]

Chitosan/polyvinylpyrrolidone composite films containing hydroalcoholic Ziziphora clinopodioides extract were developed and evaluated for their potential use as wound dressings. The physical and chemical properties of the films were extensively explored, including swelling capacity, mechanical properties, antimicrobial activity, and microstructural characteristics. The results showed that the addition of Ziziphora extract significantly increased the swelling capacity of the films by 561.24% to 1175% ( p  < 0.05). While tensile strength and Young's modulus were enhanced, elongation at the breaking point decreased with increasing volume percentages of Ziziphora extract. Variance analysis indicated no statistically significant effect on the tensile properties of the films with varying Ziziphora extract content ( p  < 0.05). Furthermore, films incorporated with Ziziphora extract demonstrated antimicrobial properties. Scanning electron microscopy (SEM) analysis revealed that samples lacking Ziziphora extract had a smooth surface, while those containing the extract displayed a rough texture that may potentially accelerate the wound healing process.