Evaluation of physicochemical, mechanical, and antimicrobial properties of gelatin‐sodium alginate‐yarrow ( Achillea millefolium L.) essential oil film

Abstract

In the current study, gelatin (Ge)-sodium alginate (SA)-based edible films containing 0, 1, 2, and 3% (w/w) yarrow essential oil (YEO) were prepared using casting method. The physical, morphological, chemical, and antimicrobial properties of these films were investigated. Results indicated that elongation at break (EB), water vapor permeability (WVP), and swelling ratio (SR) increased, while tensile strength (TS), moisture content (MC), and solubility (Sol) decreased with increasing YEO content. Also, the contact angle (CA) increased from 60.11 to 89.07 by increasing YEO indicating an increase in surface hydrophobicity and also an increase in heterogeneity and unevenness in the surface of the film. The nonsignificant difference was observed between the color index involving lightness and yellowness in the SA-G film containing 0, 1, 2, and 3% YEO (p > .05); however, the addition of YEO significantly caused to change the overall color difference (ΔE) (p < .05). Fourier transform infrared spectroscopy (FTIR) analysis revealed an interaction between Ge-SA and YEO. Results obtained indicated that the antimicrobial and antioxidant properties improved, and total phenolic content (TPC) increased with increasing YEO content. Maximum diameter of the inhibition zone of the G-SA films belonged to the Pseudomonas aeruginosa, which reached 26.7 mm in the film containing 3% YEO. Result indicates the possibility of using Ge-SA film containing YEO as an active food packaging film. Novelty impact statement Gelatin-sodium alginate films containing yarrow essential oil (YEO) are suitable options as active packaging in the storage of various foods TPC, antioxidant, and antimicrobial properties of the film increased with the addition of YEO Elongation at break, water vapor permeability, and swelling ratio increased as the film increased with the addition of YEO Tensile strength, moisture content, and solubility decreased with increasing YEO content Roughness, inconsistency, and unevenness in the film surface increased with the addition of YEO