Development of Plantago ovata seed mucilage and xanthan gum-based edible coating with prominent optical and barrier properties

This study investigates the fabrication of edible coating based on Plantago ovata seed mucilage (POSM). The films were prepared from POSM (1 %, w/v), glycerol (75 %, based on POSM mass), and xanthan gum (XG: 20, 30 and 40 %, based on POSM mass) by a casting method, and their physicochemical, mechanical, thermal, morphological, and barrier properties were determined. Results indicated the development of highly transparent (transparency values: 1.36 ± 0.05 to 2.42 ± 0.09) and hydrophobic films (contact angle: 101.57 ± 0.34 to107.08 ± 0.55o) with very low water vapor permeability (WVP: 2.77 ± 0.02 × 10−12 to 1.98 ± 0.04 × 10−12 g s−1m−1Pa−1), slight water solubility (31.14 ± 0.46 to 23.08 ± 0.82 %), and good mechanical properties (tensile strength: 30.87 ± 0.96 to 61.80 ± 0.71 MPa). Morphological studies also indicated smooth and uniform surfaces without pores and cracks. In addition, the films showed good antioxidant activity (61.46 to 68.71 %), and their antibacterial activity against E. coli, S. aureus and P. aeruginosa was also demonstrated. The applicability of the developed films to extend the shelf life of strawberries was shown by comparing the appearance of dip-coated strawberries and the control sample within 8 days at room temperature. Based on the results, the developed biofilms have great potential for edible coating and packaging applications. •We develop edible coatings from Plantago ovata seed mucilage, xanthan gum and glycerol.•Very low water vapor permeability, strong hydrophobicity, and high transparency were characteristic features of biofilm.•Films showed antioxidant property and antibacterial activity against Gram-positive and Gram-negative bacteria.•Preservative effect of films on deep-coated strawberries in room-temperature storage was demonstrated.