Development and evaluation of Moringa extract incorporated Chitosan/Guar gum/Poly (vinyl alcohol) active films for food packaging applications.

The present study contributes the synthesis of active films with the incorporation of moringa extract (ME) into chitosan (CS)/guar gum (GG)/poly(vinyl alcohol) (PVA) matrix (CGPM) by simple solvent casting technique. The effect of ME on the mechanical, thermal, structural and morphological properties of CGPM active films were investigated. ME has shown a marked influence on the optical, thermal properties and swelling behaviour of CGPM active films. The improvement in the tensile strength of CGPM-1 active film (53.7 MPa) was observed compared to control CS/GG/PVA (CGP) film. DSC study revealed that glass transition temperature (Tg) and melting temperature (Tm) decreased with the addition of ME in the CGP matrix, which confirmed the miscibility among the components of active films. There was an improvement in the thermal stability of the CGPM active films. The FTIR study confirmed the molecular interaction between ME and CS/GG/PVA matrix. The XRD analysis showed a decrease in crystallinity with an increase in the ratio of CS for CGPM active films. The CGPM active films were an excellent barrier to UV- light and have exhibited a decrease in moisture adsorption and water solubility compared to CGP control film. The inclusion of ME in the CGP matrix leads to the formation of a dense compact surface, which in turn enhanced hydrophobicity of active films. The CGPM active films showed minimum WVP, OP values and overall migration values were within the limits of 10 mg/dm2. It was also observed that CGPM active films effectively inhibited the growth of E. coli and S. aureus bacteria. These findings suggest CGPM active films are biodegradable, biocompatible, non-toxic and hence can find application as food packaging materials.

Hydroxy citric acid cross-linked chitosan/guar gum/poly(vinyl alcohol) active films for food packaging applications.

The present work aims to prepare Chitosan (CS)/Guar gum (GG)/Poly(vinyl alcohol) (PVA) cross-linked with Hydroxy citric acid (HCA) (CGPH active film) by solvent casting technique. The influence of HCA on different CS/PVA ratio (1:3, 1:1, 3:1) in presence of the fixed amount of GG (0.2%) was investigated. The analysis of the results showed that the addition of HCA to the different ratio of CS/PVA increased the degradation temperature and improved the mechanical properties of CGPH active films. FTIR spectra and XRD analysis revealed strong interactions among the components of CGPH active films. The analysis of SEM images and water contact angle suggested a compact, dense film surface with hydrophobic nature. Further, all the active films have shown a decrease in water vapour permeability (WVP) and acted as a barrier to UV-light. CGPH active films effectively inhibited the growth of S. aureus and E. coli bacteria. With all these features the CGPH active films can find application in food packaging.

Ethyl vanillin incorporated chitosan/poly(vinyl alcohol) active films for food packaging applications.

Ethyl vanillin (EV) incorporated chitosan (CS)/poly(vinyl alcohol)(PVA) blend films of various ratios (1:3, 1:1 and 3:1) were prepared by solvent casting technique. The effect of EV on the mechanical, structural, barrier, optical, food compatibility and antibacterial properties of the CS/PVA films were investigated. Mechanical properties showed that addition of EV increased tensile strength of CPEV-1, CPEV-2 and CPEV-3 films by 39 %, 45 % and 86 %, respectively compared to CS/PVA matrix. The FTIR results confirmed the formation of a Schiff base (CN) and intermolecular hydrogen bonds between CS, PVA, and EV. Incorporation of EV into CS/PVA matrix (i.e. CPEV) showed the marked influence on the water vapor transmission rates (WVTRs) and oxygen transmission rates (OTRs) and exhibited excellent UV barrier capability. Surface morphology of CPEV blend films becomes smooth, homogeneous and dense as visualized through scanning electron microscopy. Contact angle measurements demonstrated the increased hydrophobicity of CPEV blend films with increasing CS content. Strong antibacterial activity was exhibited by CPEV-3 blend films against both E. coli (Escherichia coli) and S. aureus (Staphylococcus aureus) bacteria. The overall migration values of CPEV blend films were 103 times lower than acceptable limits of 10 mg/dm2. Therefore, CPEV blends have good potential to be considered as sources of active films for food packaging applications.

Influence of boswellic acid on multifunctional properties of chitosan/poly (vinyl alcohol) films for active food packaging.

Present work aimed to develop active packaging films based on chitosan (CS), poly (vinyl alcohol) (PVA) and boswellic acid (BA), and to evaluate the effect of BA on multifunctional properties of CS/PVA (CPBA) active films. Different compositions of active packaging films were prepared by the solvent casting method. The results indicated that incorporation of BA enhanced the ultraviolet blocking, morphology, mechanical properties, water solubility and hydrophilicity of the CPBA active films. Significant improvement in the barriers properties of BA incorporated CPBA active films were observed. The microbiological screening has demonstrated the antimicrobial activity of the films against Escherichia coli, Staphylococcus aureus and Candida albicans. Furthermore, the prepared active films do not deteriorate the thermal properties after incorporation of BA. The overall migration values of the CPBA active films in contact with food simulants were within the permitted limits. The obtained results indicate that the CPBA active film may be a promising material for food packaging applications.