Yam starch-based sustainable edible films loaded with bioactive components from aroeira leaf extract: Mechanical, physical, and antioxidant properties

Abstract

This study aimed to investigate the impact of adding aroeira leaf extract (Schinus terebinthifolius Raddi) to a yam starch film matrix, focusing on the development of potentially active films and the evaluation of their physicochemical, mechanical, optical, and antioxidant properties. Films were produced using the casting method with varying extract concentrations (0, 3, 6, 12, and 15 %), yam starch (2 %), and glycerol (1 %). The antioxidant properties were analyzed by determining the total phenolic content, 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) radical scavenging, ferric reducing power, and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical elimination, which revealed a significant increase in antioxidant properties as the extract concentration increased. The incorporation of the extract resulted in increased film thickness and decreased solubility, water activity, and moisture, as well as changes in brightness (L*), tensile strength, and elongation. X-ray diffraction (XRD) showed an increase in the crystallinity of the films, whereas Fourier-transform infrared (FTIR) analysis revealed similar spectra among the films. The thermal stability did not exhibit significant variations with the addition of the extract, indicating high heat resistance. Films with 15 % extract showed changes in the surface microstructure, indicating greater roughness than the control film. Thus, formulations with 3 %, 6 %, and 9 % aroeira extract emerged as the most promising, suggesting their potential for application in active packaging and as a sustainable alternative for food preservation.

Keywords: Active film; Active packaging; Antioxidant capacity; Aroeira extract; Natural aditive; Yam starch.