Synergistic effects between κ-carrageenan and locust bean gum on physicochemical properties of edible films made thereof

The development of mixed systems, formed by locust bean gum (LBG), and kappa-carrageenan (kappa-car) can offer new interesting applications such as the development of edible films with particular properties. kappa-car/LBG blend films with different ratios were developed, and their effects on films' physical properties were assessed. Thermogravimetric analysis (TGA), X-ray diffraction (XRD) patterns, dynamic mechanical analysis (DMA) and Fourier-transform infrared (FTIR) spectroscopy techniques were used to highlight the interactions between the two polysaccharides. The addition of kappa-car to LBG improved the barrier properties of the films leading to a decrease of water vapor permeability (WVP). Improved values of elongation-at-break (EB) were registered when the ratio of kappa-car/LBG was 80/20 or 40/60 (% w/w). Moreover, the kappa-car/LBG blend films enhance the tensile strength (TS) compared to kappa-car and LBG films. FTIR results suggested that hydrogen bonds interactions between kappa-car and LBG have a great influence in films' properties e.g. moisture content, WVP. Therefore, different kappa-car/LBG ratios can be used to tailor edible films with enhanced barrier and mechanical properties. (C) 2012 Elsevier Ltd. All rights reserved.