Water Sorption and Water Vapour Permeability Properties of Polysaccharide (Locust Bean Gum) Based Edible Films

Water sorption data of edible films containing locust bean gum (LBG) and polyethylene glycol (PEG) 200 as plasticizer determined at different water activities showed that equilibrium water content increases sharply above aw=0.65. The effects of the amount and molecular weight of PEG on water vapour transfer properties of these edible films were also examined. Generally, permeance and permeability values of edible films were found to increase with both quantity and molecular weight of PEG up to PEG 600. With increasing amounts of plasticizers (PEG 200, PEG 400, PEG 600), which are liquid at room temperature, a diluting effect in the film solution occured and permeance and permeability values of edible films increased. This situation was reversed for the edible films containing PEG 1000, which is solid at room temperature.