Characterization of curcumin incorporated guar gum/orange oil antimicrobial emulsion films

Edible films are manufactured from natural, renewable, nontoxic, and biodegradable polymers and are safe alternatives to plastic food packaging. Despite ongoing research, biopolymer-based edible films still are not at a quality to ensure total commercial replacement of synthetic packaging materials. The study aims to compare the effectiveness of some novel methods employed to improve edible film properties. These include dispersion of orange oil (1% & 2% v/v) and/or curcumin into guar gum (GG), glycerol and lecithin-based edible films that are further reinforced with Sodium trimetaphosphate (STMP) crosslinking with the aim enhancing films physical properties. The films were characterized by measurement of film thickness, density, moisture content, water dissolvability, FTIR Spectroscopy, opacity, water vapor permeability, tensile properties, and antimicrobial activity. Orange oil and curcumin preserved their antimicrobial activity inside the films, which bestowed the films with an active packaging function. Control GG films had acceptable tensile and barrier properties that were further improved. All other film properties, such as opacity, dissolvability, and moisture content, that should be designed for specific application, were successfully modified with the methods used. Our results confirm successful application of STMP crosslinking, emulsion film formation, and active agent addition to edible films in manufacturing GG films for packaging.