Characterization of rice starch-L-carrageenan biodegradable edible film. Effect of stearic acid on the film properties

The main aim of this study was to develop rice starch (RS), L-carrageenan (L-car)-based film. Different formulations of RS (1-4%, w/w), i-car (0.5-2%, w/w) was blended with stearic acid (SA; 0.3-0.9%, w/w) and glycerol (1%, w/w) as a plasticizer. The effect of film ingredients on the thickness, water vapour permeability (WVP), film solubility (FS), moisture content (MC), colour, film opacity (F0), tensile strength (TS), elongation-at-break (EAB) of film was examined. Interactions and miscibility of partaking components was studied by using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Hydrocolloid suspension solution of mix polysaccharides imparted a significant impact (p <0.05) on the important attributes of resulting edible film. TS and EAB of film were improved significantly (p<0.05) when u-car was increased in the film matrix. Formulation Fl comprising 2% L-car, 2% RS, 0.3% SA, Gly 30% w/w and 0.2% surfactant (tween (R) 20) provided film with good physical, mechanical and barrier properties. FT-IR and XRD results reveal that molecular interactions between RS-u-car have a great impact on the film properties confining the compatibility and miscibility of mixed polysaccharide. Results of the study offers new biodegradable formulation for application on fruit and vegetables. (C) 2016 Elsevier B.V. All rights reserved.