Effect of squalene as a glycerol substitute on morphological and barrier properties of golden carp (Probarbus Jullieni) skin gelatin film

Preparation, physicochemical and biological evaluation of chitosan Pleurotus ostreatus polysaccharides active films for food packaging

The aim of this study was to create CS-POP composite films by blending Pleurotus ostreatus stalk polysaccharides (POP) and chitosan (CS). The effects of adding different concentrations (0 %, 0.25 %, 0.5 %, 0.75 %, and 1 %) of POP on the mechanical, barrier, and optical properties of the CS films were investigated. When the POP content is at 0.5 %, the tensile strength of the composite film reaches its maximum value at 13.691 MPa, showing a significant improvement compared to the tensile strength of the pure CS film. The structure of the CS and CS-POP composite films was characterized by FT-IR spectroscopy, XRD, TGA and SEM. The results indicate that due to the interaction between the two types of CS and POP, the formation of Schiff base, and the intermolecular hydrogen bonds between CS and POP, the addition of POP to CS films can result in a smoother and more stable crystalline structure in the composite film. The CS-POP composite films exhibited enhanced antioxidant and antibacterial activity compared to the CS films alone, with the highest DPPH scavenging activity of 72.43 %. The composite films also showed significant inhibitory effects on the growth of E. coli.

Development and characterization of antioxidant bilayer film based on poly lactic acid-bitter vetch (Vicia ervilia) seed protein incorporated with Pistacia terebinthus extract for active food packaging

This study focuses on designing an active bilayer food package film based on polylactic acid (PLA) and bitter vetch seed protein incorporated with Pistacia terebinthus extract (PTE). The effect of PTE on the physicochemical, barrier, structural, mechanical, and antioxidant properties of the active film was determined. Moisture content, water solubility, and water vapor permeability (WVP) of the active films indicated that the addition of PTE increased its suitability for food packaging. FE-SEM micrographs illustrated that the resulting films had a smooth and dense surface, describing a continuous network of protein molecules within the film structure. FTIR analysis displayed the physical interaction between PTE and the film polymer. XRD revealed an increase in the crystallinity of the active films. The resulting active film had a low migration rate (<7%) of phenolic compounds into fatty food simulant. Notably, the addition of PTE significantly (P ≤ 0.05) decreased the tensile strength and Young's modulus (from 15.13 and 315.98 MPa to 14.07 and 254.07 MPa, respectively). Concurrently, there was an increase in the elongation at break of the active films (from 23.19 to 75.60%), indicating higher flexibility compared to control films. Additionally, the incorporation of PTE improved the thermal properties of active films. The antioxidant capacity of the designed films was measured based on their DPPH radical scavenging activity, revealing that the antioxidant capacity of the control film increased from 44.65% to 59.72% in the active film containing 15% PTE. In conclusion, the prepared bilayer film can effectively be used as an active food package for sensitive foods to oxidation.

Properties of fish myofibrillar protein film: effect of glycerol-sorbitol combinations

The effects of glycerol-sorbitol combinations (G/S) at different ratios (0: 2, 0.5: 1.5, 1: 1, 1.5: 0.5, and 2: 0, w/w) on the properties of fish myofibrillar protein (FMP) films were evaluated and then compared to those of synthetic wrap film (polyvinyl chloride; PVC). The thickness of FMP films plasticized with G/S at various ratios was in the range of 0.012 to 0.013 mm and transparency values were 3.81-3.86. Significant increases in elongation at break (65.81-116.53%), oxygen permeability (12.83-36.11 cm³/m²/day), and water vapour permeability (0.27-1.43 × 10^-10 g/m/s/Pa) were observed when the proportion of glycerol increased (P < 0.05). No significant difference was observed in a* and b* values, compared to the PVC film. However, tensile strength values (12.56-3.52 MPa) decreased when the proportion of glycerol increased (P < 0.05). A change in the amount of sorbitol influenced the thermal properties of FMP films. According to their properties, up to 50% of glycerol could be substituted for sorbitol in order to enhance the strength, barrier, and thermal properties of the FMP films.

Advantages and challenges of Pickering emulsions applied to bio-based films: a mini-review

The strategy of adding hydrophobic compounds to bio-based films (usually based on hydrophilic matrices), forming films containing emulsions, is a technique that has been used to improve some physical properties (such as reducing water solubility and water vapor permeability) and / or to impart properties, such as antioxidant and antimicrobial effects by carrying hydrophobic active components that would otherwise be insoluble in hydrophilic matrices. Although Pickering emulsions have been reported as presenting greater stability when compared with surfactant-stabilized emulsions, little is known about the drying stability of Pickering emulsions (which is important for film applications). Anyway, several studies have indicated that Pickering emulsions are interesting systems to improve the water vapor barrier properties of bio-based films and coatings, and to act as carriers of active hydrophobic components. On the other hand, the tensile properties of those films are usually impaired by the presence of Pickering emulsions. The objective of this review is to present recent developments and future perspectives in bio-based films loaded with Pickering emulsions. © 2020 Society of Chemical Industry.

Physicochemical and Functional Properties of Active Fish Gelatin-Based Edible Films Added with Aloe Vera Gel

Edible films based on the addition of Aloe Vera gel (AV) into fish gelatin (FG) with antimicrobial and functional properties for food packaging applications were proposed in this work. AV showed an amphiphilic nature by infrared spectroscopy, high total phenolics content (TPC), antioxidant activity and thermal stability with an initial degradation temperature of 174 ± 2 °C. Mannose and glucose were quantified as main monosaccharides whereas the linkage composition study confirmed the presence of acemannan as main active polysaccharide. Three different formulations were obtained by the casting technique and the addition of AV contents of 0, 1 and 4 wt.% to FG, showing films with 4 wt.% of AV the best performance. The addition of AV did not significantly affect mechanical and barrier properties to oxygen and water vapour. However, some structural changes were observed by infrared spectroscopy and the obtained glass transition temperature values due to intermolecular interactions that increased the hydrophilicity and solubility of the resulting FG/AV films. A higher thermal stability was observed in films with AV content increasing the initial degradation and oxidation onset temperatures. An antimicrobial activity against S. aureus was also observed for FG/AV films. The addition of AV into FG could be proposed as a potential effective material to increase the postharvest quality of packed fruits and vegetables by retarding the microbial growth and extending the shelf-life of these food products.