Physical, mechanical, optical, barrier, and antioxidant properties of sodium alginate–aloe vera biocomposite film

Abstract

Composite films of sodium alginate and aloe vera gel were prepared using sorbitol as a plasticizer. These films were studied for their physical, mechanical, barrier, optical, and antioxidant properties. The results of the study showed a direct relationship between aloe vera gel concentrations and total phenolic contents of the composite films. The phenolic compounds present in aloe vera contribute to the antioxidant properties of the composite films. The results also indicated that the antioxidant activity of the composite films increased with the increasing concentration of aloe vera reaching a maximum value at the maximum (50%) concentration of aloe vera gel. The influence of aloe vera in enhancing tensile strength was found to be more prominent, giving a maximum value of tensile strength at only 10% concentration of aloe vera gel. The results also showed that the incorporation of aloe vera gel into sodium alginate up to a concentration of 50% did not significantly alter the transparency of the composite films. The water vapor permeability of the films decreased with the increasing concentration of aloe vera in the films. The solubility of the films increased with the increasing concentration of aloe vera due to the presence of highly water-soluble compounds in aloe vera gel. Novelty impact statement Novel food packaging films based on two natural resources, that is, alginate and aloe vera have been developed. Owing to their excellent transparency and colorlessness these films visually resemble synthetic plastic films but have a distinct advantage over synthetic packaging materials, of being biodegradable and edible. By the virtue of their good mechanical strength, barrier properties, and antioxidant activity these biodegradable active packaging films are a strong candidate to replace the synthetic plastic materials presently being used in the food packaging industry which contribute to environmental pollution.