Characterisation of a new biodegradable edible film based on sage seed gum: Influence of plasticiser type and concentration

The present work dealt with investigating physicochemical, barrier, mechanical and surface properties of sage seed gum (SSG) edible films as a function of plasticiser type (glycerol and sorbitol) and concentration (20, 40, 60, 80 & 100, w/w%). Based on the results, it was revealed that glycerol and sorbitol effectively plasticise the films of SSG while glycerol efficiency was higher than sorbitol. Although the films plasticised by glycerol were of high moisture content (27-49%), moisture uptake (110-140%) and solubility in water (similar to 80%), but they exhibited low permeability to water vapour, acceptable mechanical properties, surface hydrophilicity, and transparency. In contrast, the films plasticised by different concentrations of sorbitol exhibited a low moisture content (similar to 14%), water vapour permeability (lower than 4 x 10(-11) g/m.s.Pa), and moisture uptake (below 90%) with high surface hydrophobicity but less desirable mechanical properties. The probable mechanisms of plasticising are discussed in details regarding the observed characteristics of SSG edible films. Concluding, the films of SSG in present work showed a substantial potential to be incorporated in food packaging applications. (C) 2014 Elsevier Ltd. All rights reserved.