Effect of drying methods on the sorption isotherms of plantain flour

Abstract

The demand for plantain flour has increased in recent years due to its health benefits and industrial applications, however, there is dearth of information on the effect of drying methods on the sorption isotherm of plantain flour. In the present study, moisture sorption properties for unripe plantain flour using four drying methods at temperatures 27 °C, 37 °C and 42 °C were determined for water activity 0.10 to 0.80. The data generated were modelled using Peleg, GAB, Oswin, BET and Langmuir. The results revealed that the Equilibrium Moisture Contents decreased with an increase in temperature at all the water activities considered. Also, moisture isotherms of the plantain flour were not significantly (p>0.05) affected by temperature. The coefficient of determination (R2) for the used models ranged from 0.640 and 0.986 and Peleg was the most appropriate for the adsorption isotherm of plantain flour out of all the models. The monolayer moisture content of the flour also showed that all the unripe plantain flours could be stored for longer periods at all the temperatures studied, as their Mo falls within acceptable range for storage.