Development and characterization of edible films based on flaxseed gum incorporated with Piper betle extract

Abstract

There has been a shift from use of petroleum-based plastics, causing serious environmental pollution, towards innovative and biodegradable edible packaging. The present study documents the development of composite edible films based on the flaxseed gum (FSG) modified by the incorporation of betel leaf extract (BLE). The films were assessed for physicochemical, mechanical, morphological, thermal, antimicrobial and structural characteristics. Scanning electron microscopy images indicated that the roughness decreased with an increase in BLE concentration. The water vapor permeability of the FSG-BLE films ranged from 4.68 to 1.59 × 10^-9 g s^{- 1} m^{- 2} Pa^{- 1}, lower than that of the control sample (6.77 × 10^-9 g s^{- 1} m^{- 2} Pa^{- 1}). The BLE4 (containing 10 % BLE) films had the highest tensile strength of 32.46 MPa compared to the control sample (21.23 MPa). Similarly, EAB and seal strength of the films incorporated with BLE were ameliorated. X-ray diffraction pattern and FTIR illustrated the shift of amorphous to crystalline behavior and a significant interaction among the BLE and FSG functional groups. Furthermore, the thermal stability of the treated films was not affected significantly however, they showed improved antimicrobial activity with the highest diameter of inhibition zone in the BLE4 sample. This study concluded that the FSG-BLE composite films (BLE4 in particular) can be considered as novel packaging material for food conservation coupled with a potential to enhance the shelf life of perishable food products.

Keywords: Active packaging; Antibacterial edible films; Biodegradable films; Biological activity; Water vapor permeability.