Characterization of film-forming solutions and films incorporating free and nanoencapsulated tea polyphenol prepared by gelatins with different Bloom values

Dual cryoprotection of gelatin-tea polyphenol microgels on surimi by targeting for ice inhibition and component stabilization

In this study, the gelatine-polyphenol microgels with dual cryoprotective roles were constructed by regulating the ratio of gelatin to tea polyphenols (1:50-1:250). The physicochemical attributes, ice recrystallization inhibition ability of microgels, and their dosage effects (1 %, 2.5 % and 4 %, w/w) on surimi were investigated. The results indicated that increased gelatin caused the reduced size and enhanced viscosity of microgels. Except for high viscosity and antioxidant activity, the GP-5 group also showed great IRI ability with minimum size distribution (125-214 μm2) of ice crystals. Furthermore, 2.5 G group and S group had a comparable TVB-N (3.81, 4.34 mg/100 g), TBARS (1.18, 1.32 mg/kg), sulfhydryl contents (29.52, 25.48 μmol/g) and Ca2+-ATPase activity (0.44, 0.36 μmolPi/gprot/h). Compared to uneven free water distribution of control group, S and 2.5 G group show more even immobilized-water distribution. Thereafter, the dual cryoprotective functions of microgels in surimi offer valuable insights for the development of effective antifreeze agents.

A Review of Modified Gelatin: Physicochemical Properties, Modification Methods, and Applications in the Food Field

Gelatin is a significant multifunctional biopolymer that is widely utilized as a component in food, pharmaceuticals, and cosmetics. Numerous functional qualities are displayed by gelatin, such as its exceptional film-forming ability, gelling qualities, foaming and emulsifying qualities, biocompatibility and biodegradable qualities. Due to its unique structural, physicochemical, and biochemical characteristics, which enhance nutritional content and health benefits as well as the stability, consistency, and elasticity of food products, gelatin is utilized extensively in the food business. Additionally, gelatin has demonstrated excellent performance in encapsulating, delivering, and releasing active ingredients. Gelatin's various modifications, such as chemical, enzymatic, and physical processes, were analyzed to assess their impact on gelatin structures and characteristics. Hopefully, gelatin will be more widely used in various applications after modification using suitable methods.

Enhanced mechanical and functional properties of chitosan/polyvinyl alcohol/hydroxypropyl methylcellulose/alizarin composite film by incorporating cinnamon essential oil and tea polyphenols

In this study, cinnamon essential oil and tea polyphenols were added to chitosan/ polyvinyl alcohol/ hydroxypropyl methylcellulose/ alizarin composite films to enhance their mechanical and functional properties. Their addition to the composite films enhanced their antibacterial and antioxidant properties and significantly improved its elongation at break (p < 0.05). Cinnamon essential oil reduced the water vapor permeability, water content, and water solubility of composite films and improved their transparency. The composite films with additive exhibited excellent UV-barrier ability and pH responsivity. Fourier Transform infrared spectroscopy and X-Ray Diffraction analyses confirmed hydrogen bond formation between the polymer molecules and additives. The results of Scanning Electron Microscope-Focused Ion Beam revealed improved surface and cross-section morphology of the films, leading to the generation of a cross-linked structure. Thermogravimetric and differential scanning calorimetry analysis indicated enhanced thermal stability of the composite films upon cinnamon essential oil addition. Analysis of storage quality indicators (TBARS value, TVC, and TVB-N) revealed that the composite films could prolong the freshness of surimi. The incorporation of cinnamon essential oil and tea polyphenols into the composite films has demonstrated significant potential as an effective and natural alternative for active food packaging.

Incorporation of gelatin improves toughness of collagen films with a homo-hierarchical structure

In this study, gelatin (type A and type B) with/without transglutaminase (TGase) were added to collagen fiber films to form hierarchical structure and its effects on the film were investigated. The analysis of mechanical properties indicate that gelatin significantly increased the toughness of the collagen film, where the 10 wt% type A gelatin -contained films had highest tensile strength, elongation at break and work of fracture. However, TGase crosslinking compromised the benefits of type A gelatin greatly, while type B gelatin showed a slight improvement, due to the difference in crosslinking activity between them. In the meantime, the hydrogen bonds were formed between the collagen and gelatin according to the results of the Fourier transformation infrared. In general, it is expected that the hierarchical structure formed in the collagen/gelatin films can be used as an effective strategy to enhance the collagen matrix films' mechanical properties.

Preparation and characterization of general-purpose gelatin-based co-loading flavonoids nano-core structure

Flavonoids (FLAs) possess anti-cancer, anti-viral, anti-bacterial, and anti-oxidant properties. In this study, gelatin nanoparticles (GNPs) with controllable surface potential and diameter was prepared through a modified two-step desolvation. Two well-known flavonoids, namely, low-molecular weight Genistein (GEN) and high-molecular weight Icariin (ICA), were adsorbed onto the surface of GNPs (FLA@GNPs). The characteristics of GNPs and the main parameters affecting flavonoid adsorption were studied to evaluate the adsorption capacity and structural stability of FLA@GNPs. Furthermore, co-adsorption of GEN and ICA was detected. The adsorption mechanism of GNPs with FLA was further discussed. Results showed that the low-molecular weight GEN could be effectively adsorbed by GNPs, and their entrapment efficiencies were over 90% under optimized conditions. The total drug loading of the co-adsorbed FLA@GNPs was significantly higher than that of the single drug loaded (GEN or ICA). GEN@GNPs could maintain its structural stability under acidic conditions (pH = 2) at room temperature (25 °C). This protective function enables both ICA and GEN to be bioactive at room temperature for at least 180 days. The characteristics of GNPs adsorption indicate that the hydrogen bonding theory of the combination of gelatin molecules with polyphenols cannot sufficiently explain the binding of GNPs with polyphenols. FLA@GNPs is a promising general-purpose gelatin-based co-loading preload structure with simplified operation and storage condition.

Preparation and properties of polylactic acid-tea polyphenol-chitosan composite membranes

To study the properties of composite membranes consisting of polylactic acid (PLA), tea polyphenol (TP), and chitosan (CS), the stretch film method was employed to make PLA-TP- CS composite membranes of different concentrations. By testing the density, mechanical properties, heat-sealing performance, water vapor permeability, and solubility of the pure PLA membrane and the composite membranes, the comprehensive performance of the composite membranes were analyzed with regard to the actual use value. The results show that, compared with the pure PLA membrane, adding TP and CS significantly increases the heat-sealing strength, water vapor permeability, and solubility of the composite membrane. When the composite membrane is used for the preservation of cherries, it is found that the composite membrane with the mass ratio of TP to CS of 3:7 can decrease the rotting rate and mass loss rate significantly, postpone the consumption of soluble solids and vitamin C, maintain the quality of the cherries, and extend the shelf life, thus proving its potential for application in food packaging.