Moisture sorption isotherm of edible film made from carrageenan and carboxy methyl glucomannan

Abstract

Edible films from carrageenan and carboxymethyl glucomannan without adding any plasticizer were processed by a solution casting method. The moisture sorption isotherm of the films was determined gravimetrically over a relative humidity of 6.1 - 97% at 30°C and 40°C. Results showed that the equilibrium moisture content increased significantly above a w =0.8. Three models of moisture sorption isotherm (Caurie, GAB, and Peleg) were applied to describe the moisture sorption behavior. The Peleg equation was found to be the most suitable for describing the sorption data.