Moisture sorption isotherm characteristics of sago flour

Abstract

Abstract The equilibrium moisture content of sago flour is essential information, especially for predicting the product’s shelf-life, which can be affected by various factors, such as temperature, relative humidity, and packaging condition. This research was conducted to study the characteristic of moisture sorption isotherm and determine the best mathematical equation model for studying sago flour’s isotherm sorption characteristics. Sago flour was stored in an incubator at a 10-80% humidity range with temperature variations of 30°C and 40°C. Humidity setting was done using various types of salt solutions. This study showed that all the sorption curves were found to be Type II. The higher the RH in the incubator, the higher the equilibrium moisture content of the material. Meanwhile, the water sorption capacity decreased with increasing temperature. Different models were fitted to the data, including Oswin, Chung-Pfost, and Halsey models. The Chung-Pfost model was found as the best model to represent the experimental data in the water activity range of 0.1-0.8.