Self-assembling crystals of an extract of Flos Sophorae Immaturus for improving the antioxidant, mechanical and barrier properties of a cassia gum film

Preparation of Nanocomposite Biopolymer Films from Commelina coelestis Willd Starch and Their Nanostructures as a Potential Replacement for Single-Use Polymers

This study explored the effect of incorporating cellulose and starch nanoparticles, obtained from the Commelina coelestis Willd plant, on the physical and chemical properties of starch-based films derived from the same plant. Additionally, the synergistic effect of combining the nanostructures was assessed. The nanocomposite biopolymer films were prepared by the casting method using 1 and 3 wt% concentrations of the nanostructures (CNCs: cellulose nanocrystals, CNFs: cellulose nanofibers, SNCs: starch nanocrystals), or their blend. The physicochemical (swelling capacity and water solubility), morphological (SEM and AFM), thermal (DSC and TGA), and mechanical properties (tensile strength, elongation at break, and Young's modulus) of the films were evaluated. The nanocomposite biopolymer films exhibited better dimensional stability (40-60%) than the control films. Tensile strength (8-300%) and Young's modulus (15-690%) were improved. Moreover, these films displayed enhanced thermal stability, withstanding temperatures exceeding 305 °C. FTIR spectra evidenced intermolecular interaction among the matrix and nanostructures. Microscopic analyses further supported the integrity of the films, which displayed a homogeneous surface and the absence of fractures. In addition, the nanocomposite biopolymer films prepared with 1 wt% cellulose nanocrystals and nanofibers had a lower opacity than those with a higher percentage (3 wt%). Overall, our findings suggest that the Commelina coelestis Willd is a promising starch source that can be used to obtain nanocomposite biopolymer films as an alternative to produce novel, efficient, and eco-friendly materials with adequate thermo-mechanical properties intended to replace conventional plastic materials in single-use applications such as those used in the food packaging industry.

Enrichment of antioxidant peptides by interfacial modification of oat polypeptides induced by zinc ions

The pursuit of methods to enhance the purity of food-sourced bioactive peptides continues to pose significant challenges. This study introduces an innovative approach to enrich antioxidant peptides by using zinc ion coordination to augment the foaming capabilities of oat peptides. The resulting antioxidant peptide fraction (AF) accounted for 18 % of the oat globulin hydrolysates, with a significant increase (22-47 %) in scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), OH, and O2- radicals. Proteomics identified 479 peptide segments within AF, and the HipHop analysis further identified 340 antioxidant peptides. Notably, the larger peptides (7-23 amino acids) were the primary contributors to the antioxidant activity, featuring key pharmacophores, i.e., charge centers, hydrophobic centers, and hydrogen bond acceptors. The AF and its key monomers (DDTKTWPEDL, YSTDPANPTKSA, NKREQQSGNNIF, and QVGQSPQYQEG) exhibited potent inhibitory effects on tyrosinase (IC50, 18.60-46.20 μg/mL) and provided strong inhibition against lipid oxidation, indicating great potential for applications in health supplements and food preservation.

Gelatin Improves the Performance of Oregano Essential Oil Nanoparticle Composite Films-Application to the Preservation of Mullet

In this study, the addition of oregano oil chitosan nanoparticles (OEO-CSNPs) was conducted to enhance the comprehensive properties of gelatin films (GA), and the optimal addition ratio of nanoparticles was determined for its application in the preservation of mullet. Oregano oil chitosan nanoparticles were organically combined with gelatin at different concentrations (0%, 2%, 4%, 6% and 8%) to obtain oregano oil-chitosan nanoparticle-GA-based composite films (G/OEO-CSNPs), and thereafter G/OEO-CSNPs were characterized and investigated for their preservative effects on mullet. Subsequent analysis revealed that OEO-CSNPs were uniformly dispersed in the GA matrix, and that G/OEO-CSNPs had significantly improved mechanical ability, UV-visible light blocking performance and thermal stability. Furthermore, the nanoparticles exhibited excellent antioxidant and antibacterial properties, and they improved the films' suitability as edible packaging. The attributes of the G/OEO-CSNPs were optimized, the films had the strongest radical scavenging and lowest water solubility, and electron microscopy also showed nanoparticle penetration into the polymer when the concentration of OEO-CSNPs was 6% (thickness = 0.092 ± 0.001, TS = 47.62 ± 0.37, E = 4.06 ± 0.17, water solubility = 48.00 ± 1.11). Furthermore, the GA-based composite film containing 6% OEO-CSNPs was able to inhibit microbial growth, slow fat decomposition and protein oxidation, reduce endogenous enzyme activity, and delay the spoilage of mullet during the refrigeration process, all of which indicate its excellent potential for meat preservation application.

An Edible and Quick-Dissolving Film from Cassia Gum and Ethyl Cellulose with Improved Moisture Barrier for Packaging Dried Vegetables

A quick-dissolving edible film was made from cassia gum (CG) incorporated with ethyl cellulose (EC). Mechanical results show that addition of 5% EC based on CG gave rise to the highest tensile strength (TS) of the composite film. Scanning electron microscopy revealed that excess addition of EC slightly decreased the homogeneousness of films. Fourier transform infrared spectroscopy showed that the compatibility between CG and EC was good and the incorporation of EC changed the original interaction of molecules by forming hydrogen bonds with CG. Although film light transmittance decreased, it is transparent enough for packaging. The film water vapour barrier property improved dramatically by blending CG and EC, although they showed dissolution rates over 80% in boiling water after 5 min. The dried carrot cube packaged by CG-EC films showed lower mass growth rates in 53% RH. Therefore, the film presents a potential application in packaging of dried vegetables in convenience foods.

Effect of ethanol extract of black soybean coat on physicochemical properties and biological activities of chitosan packaging film

Chitosan (CS) with an ethanol extract of black soybean coat (EBSC) was prepared, and its physicochemical properties and antioxidant and antibacterial activities were tested. The results showed that EBSC significantly increased the thickness and UV-Vis light barrier ability of the CS-based films, while the swelling degree, water vapor permeability, and tensile strength decreased. The CS-EBSC films had smooth surfaces, compact cross-sections, and no cracks, and they had higher crystallinity than the CS film. Fourier transform-infrared spectroscopy indicated that there were noncovalent bonds (hydrogen bonds) between EBSC and CS. Furthermore, the CS-EBSC III film presented a stronger ABTS radical scavenging ability (66.58%) and could effectively inhibit Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. The lipid oxidation test proved that CS-EBSC films significantly reduced the peroxide value of lard. The results above indicate that CS-EBSC films could be used as an active packaging material to improve the shelf life of food.