Development of novel ecofriendly sodium alginate-gelrite gellan gum composite films: Effects of glycerol and sorbitol

The current study investigated the impact of various concentrations of plasticizers, especially glycerol and sorbitol, on the physical and chemical characteristics, as well as the antioxidant capabilities, of films made from sodium alginate and gelrite gellan gum. The elongation at break and thickness of the film samples increased, while water vapor permeability, opacity, and tensile strength of the film samples decreased with the increase in concentration of plasticizers. Film samples became more transparent and glossier in nature with increasing concentrations of plasticizers. Scanning electron microscopy revealed that sorbitol-loaded films showed a smooth and homogenous structure as compared to glycerol-loaded film samples. The control film samples showed significantly higher antioxidant activity compared to the other film samples. Contact angle measurements demonstrated that the film samples became more hydrophilic with the addition of plasticizers. This study provides an overview of the role of plasticizers, including glycerol and sorbitol, in the fabrication and application of biopolymeric films for food packaging.

Highlights

• Plasticizers increased EAB and thickness but decreased WVP, opacity, and TS.
• Films with higher plasticizer levels were more transparent and thinner.
• Sorbitol-loaded films were more homogenous than glycerol-loaded ones.
• Control films had higher antioxidant activity than plasticizer-added films.
• Increase in plasticizer level increased hydrophilicity of films