The current study investigated the physicochemical and structural properties of different ratios of psyllium gum (PG) and modified starch (MS) (100:0, 50:50, 75:25, 0:100) composite films. The results indicated that the moisture content, water solubility, water vapor permeability (WVP), and tensile strength (TS) of films decreased with increasing proportions of PG. However, the films’ elongation at break (EB) increased with gum content >50%. Cross‐sectional scanning electron microscopy (SEM) of composite films showed homogeneity, integrity, and a smooth structure. The results of differential scanning calorimetry (DSC) indicated a reduction of thermal stability with increasing proportions of PG. The films’ Fourier transform infrared spectroscopy (FTIR) spectra indicated miscibility and good interactions between MS and PG. These findings were in agreement with the results of physicochemical, mechanical, morphological, and thermal analyses. The PG/MS composite films with improved properties have potential for use in food packaging. Practical applications The film forming is a technique that polymer(s) combine with together and may be created cross‐linked between them. The combination of polymers for film forming was used for reinforcement and stability the films networks. In this study, the composite edible films of psyllium gum/modified starch made and the physicochemical, mechanical, and structural properties of films was measured.

This study investigated the effects of nano‐silicon dioxide (nano‐SiO2) (0%, 0.5%, 1%, and 1.5%) and the ratio of PVA/gelatin (1:1 and 2:1) on the physicochemical and structural properties of gelatin/polyvinyl alcohol composite films. The results showed that the highest value of tensile strength (18.05 MPa) was found for a PVA/gelatin ratio of 2:1 and 1% nano‐SiO2 (P2:G1‐1%). The films’ elongation at break value increased with increases in the nano‐SiO2 and PVA content, while their water solubility decreased with the addition of nano‐SiO2. Their water vapor permeability decreased with 1% nano‐SiO2, and the lowest value for water vapor permeability was with P2:G1‐1%. Fourier transform infrared and differential scanning calorimetry results showed that appropriate interaction between both polymers and nano‐SiO2 was found with P2:G1‐1%. Scanning electron microscopy illustrated a compact structure and good compatibility of nano‐SiO2 with gelatin in P1:G1‐1% film. X‐ray diffraction results showed that the crystallization peak intensity of P2:G1‐1% was higher than that of P1:G1‐1% nanocomposite films. Overall, the results indicated that the concentration of 1% of nano‐SiO2 in P2:G1 films significantly improved the films’ physicochemical and structural properties. These results suggest that they could be useful as food‐packaging materials to maintain food quality. Practical application Gelatin films possess properties that make them useful in packaging, such as water vapor resistance and low values for mechanical properties. PVA as a synthetic polymer, have good tensile strength asz and biodegradability along with high numbers of hydrophilic groups. PVA has also been used in many biomaterial applications. Some advantages of nanomaterials such as silica nanoparticle are high mechanical strength, biocompatibility, and biodegradability. In the present study, nano‐SiO2 was used in films blended from PVA and gelatin. The improved physicochemical and structural properties achieved through the use of nano‐SiO2 could make the films more effective as food packaging.

This study investigated a novel method of photosensitizer-induced cross-linking (using riboflavin as a sensitizer) to improve the structural and physicochemical properties of gelatin-based edible films with different glycerol concentrations (25% and 50%) during different UV exposure times (2, 4 and 6 h). The films' tensile strength was enhanced significantly for both glycerol concentrations with increasing UV exposure times compared to the control film, so that the highest tensile strength was observed for films with 25% glycerol and 6 h of UV exposure (25%-6 h). The films' tensile strength declined and the elongation at break increased about three times when the glycerol concentration was increased to 50% with 6 h exposure. The photosensitizer-induced cross-linking significantly reduced the films' solubility and permeability. The UV-treated films exhibited very good barrier properties against UV, with zero light transmission at a wavelength of 200 to 350 nm. Moreover, no toxicity was found in any of the films. In addition, Fourier transform infrared spectroscopy and differential scanning calorimetry findings revealed a good interaction between functional groups of riboflavin (as the sensitizer) and gelatin in the 25%-6 h film. Therefore, this new method can be a suitable alternative to chemical methods of cross-linking biopolymers.

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Background: Plantago ovata Forsk (Psyllium seed) is an annual plant of plantago genus. This plant widely grows in India and Iran. The Psyllium seed contains mucilage, protein, sugar, fat and tannins. Seed’s husk is a known source to extract hydrocolloid. Objective: The aim of this study was to optimize gum extraction from the Psyllium seed. Methods: The response surface methodology (RSM) was used to estimate the effect of independent variables on the extraction yield of Psyllium gum. The obtained experimental data were fitted to a second- order polynomial equation using multiple regression analysis and analyzed by appropriate statistical methods. A central composite design (CCD) was used for experimental design and analysis of the results to obtain the best possible combination of extraction temperature (X1= 60-80°C), extraction time (X2= 1-3 h), and the ratio of water to raw material (X3= 30-70%) for the maximum gum extraction. Results: Optimum extraction conditions were extraction temperature of 79°C, extraction time of 2.5 h, and the ratio of water to the raw material of 57%. The experimental extraction yield under optimal conditions was found to be 9 ± 0.25%, which was in agreement with the predicted value of 9.4%. Conclusion: This study showed that Psyllium gum can be used as a hydrocolloid source for pharmaceutical and food industry such as edible films for food packaging.