Development of active edible coating of alginate and aloe vera enriched with frankincense oil for retarding the senescence of green capsicums

The application of alginate-based coatings in food preservation is limited owing to their poor antimicrobial, UVshielding, and water-barrier properties. For this concern, multifunctional alginate films were designed for the preservation of green capsicums through the incorporation of aloe vera (AV) and frankincense oil (FO). FTIR confirmed the successful incorporation of AV and FO while XRD showed a crystallinity reduction in the presence of FO. Significant improvements in thermal stability and mechanical properties were achieved in the presence of AV and FO. The addition of AV and FO made the films more bright, yellow and green meanwhile the film's transparency was not significantly influenced. A significant UV-shielding was detected upon increasing either AV or FO. Water vapor permeability was significantly reduced from 21.53 +/- 1.43 g mm/m2 day kPa for alginate to 8.18 +/- 0.24 g mm/m2 day kPa for the film containing AV at 67% and FO at 6%. Excellent inhibition activities against different bacteria and fungi were obtained for the films containing AV and FO. The prepared films exhibited excellent senescence retardation and resistance to the mass loss for green capsicums. Due to their enhanced UV-barrier, physical and microbial-inhibition properties, the prepared active films might be potentially used in food preservation.

Automated summary

The incorporation of aloe vera and frankincense oil improved the antimicrobial, UV-shielding, and water-barrier properties of alginate films for the preservation of green capsicums. The addition also enhanced thermal stability, mechanical properties, and reduced water vapor permeability. The active films showed excellent inhibition activities against bacteria and fungi, making them potentially useful in food preservation.