Search

Highlights: [•] Biodegradable zein-based films were prepared. [•] The hydrophobicity of zein films was investigated. [•] DSC was used to study the thermal stability of zein films. [•] FTIR amide I deconvolution of zein films prepared from ethanol and isopropanol was shown. [ABSTRACT FROM AUTHOR]

Highlights: [•] Zein nanoparticles in ethanol and isopropanol were prepared. [•] Sulfhydryl groups of zein nanoparticles in ethanol and isopropanol were investigated. [•] AFM was used to study the microstructure of zein particles. [•] Rheological properties of zein suspensions prepared from ethanol and isopropanol was studied. [Copyright &y& Elsevier]

Highlights: [•] Zein and poly(propylene carbonate) were utilized in the preparation of films. [•] The combination of the acetone-pretreatment and extrusion using a conical twin-screw extruder utilized in the manufacture of films. [•] The mechanical properties, the water absorption, the film transparency, the microstructure and thermal stability of the film were characterized. [•] The Halsey model was identified as an ideal model for this study. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Highly dispersible TiO 2 was successfully applied to prepare zein/CS/TiO 2 films. • The films modified by nano-TiO 2 showed better mechanical properties than control. • The films modified by nano-TiO 2 showed better thermal stability than control. • Significant antibacterial activity against gram-negative and gram-positive bacteria. Abstract Highly dispersible TiO 2 nanoparticles were prepared through the hydrolysis of titanium alcohol, and a series of TiO 2 -modified zein/chitosan (CS) films were prepared through a process involving blending, solution casting and evaporation. The mechanical properties and the antibacterial capacity of the zein/CS/TiO 2 films were characterized to explore the effects of different TiO 2 nanoparticle contents. Results showed that the addition of nanoscale TiO 2 remarkably improved the mechanical properties and thermal stability of the zein/CS/TiO 2 film. The tensile strength of the zein/CS/TiO 2 films significantly increased (p<0.05) with the increasing TiO 2 loadings in films, reaching a maximum of 28.33 ± 1.53 MPa at 0.15 wt % TiO 2 nanoparticles. The antibacterial effect of the composite films on Gram-positive bacteria (S. aureus) was more significant than that of Gram-negative bacteria (E. coli and S. enteritidis), and the antibacterial effect of UV light was better than that of dark conditions. In particular, the inhibition zones of zein/CS/TiO 2 (0.15%) film against E. coli , S. enteritidis and S. aureus under UV light condition increased by 21.78%, 21.45%, and 26.44%, respectively, compared with the control. This study suggested that adding highly dispersible TiO 2 nanoparticles is an effective method for improving the mechanical and antimicrobial properties of zein/CS films for various applications, such as medical and food packaging. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A novel two-step modification was applied for enhancing functional properties of zein films. • Cold plasma gave zein-based films a rougher and more hydrophilic surface. • Flexibility and barrier properties were significantly increased after modification. • Cold plasma enhanced the compatibility between zein and chitosan molecules. Abstract In order to improve their functional properties, zein films were modified by a two-step method consisting of compositing with chitosan, followed by exposure to cold plasma. Various aspects were assessed to evaluate the influence of modification on the properties of the films. After the two-step modification, the water contact angle of the zein films significantly dropped from 75.18° to 29.19°. Moreover, the films showed a notable increase in their elongation at break, from 1.13% to 4.13%, mainly attributed to the presence of chitosan. Additionally, upon a 60 s plasma treatment, the composite film exhibited an optimum tensile strength, an enhanced water vapor barrier as well as improved thermal stability. Evaluation with ATR-FTIR revealed the secondary structure of zein molecules became ordered and found the more hydrogen bonds formed between zein and chitosan with plasma treatment. This study showed the benefits of our two-step modification to potentially improve zein-based film performance in packaging industries. [ABSTRACT FROM AUTHOR]

In the present study, the nonhazardous atmospheric cold plasma (ACP) technique was introduced to improve the surface hydrophilicity and mechanical strength of zein film. The results indicated that the surface hydrophilicity was significantly increased after ACP treatment, with a drop of contact angle from 72.85 ± 2.33° (untreated) to 48.42 ± 1.57° (ACP–60 s). Increased surface roughness and enrichment of the oxygen- and nitrogen-containing groups were responsible for this modification. As the X-ray photoelectron spectroscopy (XPS) results shown, the O1 s and N1 s peak intensity was dramatically enhanced after 30 s ACP treatment with an increased O/C ratio from 0.64 to 1.09. Storage in ambient environment for an extra 24 h of treated film could further reduce the contact angle. With the treatment time extending, enhanced tensile strength (TS) and flexibility were observed in zein films, accompanied by improving thermal properties, which indicated the cross-linking within protein matrix. Moreover, ACP treatment could significantly decrease the water vapor permeability (WVP) due to the increasing tortuosity of the diffusion pathway after plasma treatment. The secondary structure in amide I band (1600–1700 cm −1 ) indicated that there was a transformation from β-turn and α-helix into β-sheet induced by ACP treatment. This research opens up new opportunities that ACP could be developed as a modification method of zein film for better utilization in packaging industry. [ABSTRACT FROM AUTHOR]

Ethanol volume fraction of 80% was widely applied for polysaccharides precipitation from Codonopsis pilosula water-leach liquor, while few researches focused on the dissolved components in 80% alcohol solution. Selenium nanoparticles presented strong biological activities with low toxicity, but the poor stability limited the practical applications. This study isolated a C. pilosula polysaccharide from the supernate after 80% ethanol precipitation, which was used as surface decorator for nano-composites preparation, and then the structural performance, storage stability and inhibitory mechanism on HepG2 cells were investigated. Results showed that the C. pilosula polysaccharide was mainly composed of fructose and glucose (molar ratio of 2.68:1.00) with average molecular weight of 3.21 × 103 Da. Additionally, the nano-composites were successfully prepared under Na 2 SeO 3 to polysaccharide (2.0 mg/mL) ratio (w:w) of 1:20, and exhibited homogeneous distribution with an average particle size of ~ 75 nm and superior stability at 4 °C for at least 35 days. Besides, the nano-composites effectively inhibited HepG2 cells proliferation dose-dependently, and induced the mitochondrial dysfunction via improving Bax expressions and descending Bcl-2 expressions, resulting in the release of mitochondrial cytochrome c to cytoplasm and the activation of caspase-9 / − 3, thereby promoting cells apoptosis. These results would effectively improve utilization rate of C. pilosula and provide theoretical foundation for clinical applications of the composite in hepatoma-bearing patients. • The novel fructose-enriched polysaccharide was prepared from Codonopsis pilosula. • The composites were prepared by selenium nanoparticles and the polysaccharide. • The prepared composites exhibited good dispersity and high stability. • The composites could effectively inhibit the proliferation of HepG2 cells. • The HepG2 cells were induced apoptosis mediated by caspase-9 and caspase-3. [ABSTRACT FROM AUTHOR]

The Codonopsis pilosula polysaccharide have been widely extracted through water dissolution and ethanol precipitation, and presented immunoregulatory and antioxidant activities. However, the polysaccharide from the supernatant was always discarded and rarely reported. In the present study, the extraction process, preliminary structural characteristics, immunoregulatory and antioxidant activities in vivo of C. pilosula polysaccharide prepared from the supernatant after 80% ethanol precipitation were evaluated and analyzed. Results showed that the optimized conditions for fructose-rich polysaccharide (Fru/Glc ratio of 2.73:1.00 with average molecular weight of 3.24 × 103 Da) extraction were determined as follows: liquid to material ratio of 40 mL/g, extraction time of 60 min, ultrasonic power of 370 W, and extraction temperature of 60 °C, and the yields reached to 6.52 ± 0.36%. Animal experiments demonstrated that the polysaccharide could effectively protect the immune organs, enhance the immune cells activities, and improve the leukocytes amounts and the expression levels of immune-related cytokines dose-dependently in CTX-treated mice, which was mainly attributed to the enhancement of antioxidant enzymatic activities and suppression of oxidative damage. These results suggested that the polysaccharide had the potential to be a natural antioxidant supplement due to the feasibility of industrial production and practical application. • The Codonopsis pilosula polysaccharide was isolated from 80% ethanol supernatant. • The maximum polysaccharide yield was 6.52 ± 0.36% optimized by Box-Behnken design. • The polysaccharide was a fructose-rich polysaccharide with molecular weight of 3.24 × 103 Da. • The polysaccharide exhibited strong immunoregulatory and antioxidant effects in vivo. [ABSTRACT FROM AUTHOR]

Cynanchum paniculatum has been applied for various diseases treatments, however, the polysaccharide components especially extracted using ethanol were rarely researched. In this study, ethanol solution with volume fraction of 75% was used for C. paniculatum polysaccharide preparation, and the extraction process optimization, structural characteristics, and bioactivities analysis were investigated. Results showed that extraction yield reached to 4.79 ± 0.24% under extraction temperature of 60 °C, extraction time of 4.5 h, liquid/solid ratio of 30 mL/g. Chemical constitutions and monosaccharide compositions, molecular weight determination results showed that the polysaccharide was mainly composed of glucose and xylose with a molar ratio of 1.00:0.63 (carbohydrate content of 94.91%, molecular weight of 5.1 kDa). Periodate oxidation, smith degradation, methylation, fourier transform infrared spectra and nuclear magnetic resonance analysis demonstrated that the glycosidic bonds configurations were mainly comprised of (1→2)-α- D -Glc p (39.86%), (1→2,4)-α- D -Glc p (10.32%) and (1→4)-β- D -Xyl p (29.58%). The bioactivities determination experiments results suggested that the polysaccharide exhibited strong antioxidant activities and antitumor effects both in vitro and in vivo. These data indicated that the ethanol-extracted polysaccharide from C. paniculatum holds great application prospect as a novel bioactive adjuvant in the future due to the feasibility of industrial production. • The polysaccharide was extracted from Cynanchum paniculatum using 75% ethanol. • The maximum extraction yield was 4.79 ± 0.24% optimized by Box-Behnken design. • The polysaccharide was composed of glucose and xylose (molar ratio of 1.00:0.63). • The polysaccharide was comprised of (1→2)-Glc p (39.86%) and (1→4)-Xyl p (29.58%). • The polysaccharide exhibited strong antioxidant and antitumor effects. [ABSTRACT FROM AUTHOR]

• The novel polysaccharides were extracted from Salvia miltiorrhiza by 60 % ethanol. • The proper extraction conditions for this crude polysaccharides were optimized. • The polysaccharides (6.50 × 103 Da) was composed of Gal/Glc/Fru (1.00:0.45:0.28). • The polysaccharides could notably improve immune levels of immunocompromised mice. Salvia miltiorrhiza polysaccharides were generally extracted using distilled water as solvent and showed various bioactivities in vivo , however, the preparation, structure, and immunomodulatory effects of polysaccharides with 60 % ethyl alcohol extraction were rarely reported. In the present study, S. miltiorrhiza polysaccharides was prepared using 60 % ethanol and the extraction process was optimized, then the structural characteristics and immunomodulation activity were investigated. Results showed that optimal extraction conditions for crude polysaccharides were determined as follows: liquid/solid ratio of 22 mL/g, extraction temperature of 60 °C, ultrasonic power of 205 W, ultrasonic time of 125 min, and the yields reached to 5.99 ± 0.09 %. Structural determination results demonstrated the purified polysaccharides showed a average molecular weight of 6.50 × 103 Da with Galactose/Glucose/Fructose ratio of 1.00:0.45:0.28. Animal experiments indicated that the polysaccharides could effectively enhance immune cells activities, and improve lymphocytes subsets proportions and immune-related cytokines expression levels dose-dependently in cyclophosphamide-treated mice. These results would provide a theoretical basis for industrial production and practical application of the novel polysaccharides as an immunoregulation adjuvant. [ABSTRACT FROM AUTHOR]

• A novel two-step strategy aimed at improving the properties of zein films. • Cold plasma pre-treatment promoted the formation of well-ordered porous PLA coating. • Improved mechanical, hydrophobic, and UV barrier properties of zein films. • The novel coating films displayed excellent biodegradability within 21 days. In this study, a two-step strategy is proposed to form a porous polylactic acid (PLA) coating on zein films aimed at improving their function. The effect of cold plasma (CP) pre-treatment on the structure and the properties of the films were evaluated. The CP pre-treatment augmented the compatibility and adhesiveness between the zein and PLA layers. The subsequent breath-figure assembly compacted and ordered the porous morphology structure of the PLA layer. Analysis by attenuated total reflectance Fourier transform infrared spectroscopy confirmed that the CP pre-treatment led to a change in the protein conformation and promoted hydrogen bonding interactions between zein and PLA. Exposure of the zein to the CP for 60 s before PLA coating improved the surface hydrophobicity by 24.11 %, the tensile strength by 50.47 %, the elongation at the break by 29.67 %, and water vapor barrier by 44.34 % compared with the untreated zein film. Moreover, the modified coating films exhibited a high UV barrier and excellent biodegradable performances. The strategy of adding a porous PLA coating on the zein films achieved the properties enhancement of zein and expanded its application scope, especially in the field of biodegradable packaging. [ABSTRACT FROM AUTHOR]