Evaluation of antimicrobial and physicochemical properties of the edible film based on sodium caseinate containing nettle extract

Abstract

Adding natural antimicrobial compounds to food packaging is a common method of producing active packaging. Nettle extract has antibacterial properties against both gram-positive and gram-negative bacteria. In this study, sodium caseinate films containing nettle extract (at three levels of 1, 3 and 5 w / w) were produced and their physical, mechanical, morphological, and antimicrobial properties were evaluated. The results showed that the inhibitory effect of films containing nettle extract on gram-positive bacteria was greater than on gram-negative bacteria. The addition of nettle extract to sodium caseinate-based films increased water solubility, water vapor permeability and thickness, and reduced film tensile strength, percentage of elongation at rupture, and transparency.Scanning electron microscopy images also confirmed the results. Based on the results, it can be concluded that nettle extract can be a suitable antimicrobial agent for the production of food films based on sodium caseinate, which retains their physical and mechanical properties, for packaging various foods, especially food. Sensitive to gram-positive bacterial species.

Keywords

• biopolymer
• biodegradable
• food film
• sodium caseinate
• nettle
• scanning electron microscope