Desorption characteristics of fluted pumpkin seeds (Telfairia occidentalis)

Abstract

The moisture sorption isotherms of Telfairia occidentalis  was determined at 20, 25 and 30 ºC, over a relative humidity range of 11-95% using the static gravimetric technique. . Eight saturated salt solutions were used to provide constant relative humidity. The samples were weighed until constant weights were attained and Equilibrium Moisture Contents (EMC) were calculated. The experimental data were fitted into five models: Guggenheim-Anderson-de Boer (GAB), Modified Oswin, Modified Henderson, Halsey and Chung-Pfost. The models were linearised and a linear regression program was employed to analyse the data. Best models fitting were determined based on highest coefficient of determination (R²), lowest Standard Error of Estimate (SEE), and lower values of Root Mean Square Error (RMSE).  The experimental sorption isotherm of Telfairia occidentalis followed the characteristic shape of type II isotherms. All the five models gave the best fit with R² (0.95 – 0.98), SEE (0.03 – 0.44), and RMSE (0.005 – 0.095) with the exception of Chung-Pfost at 20^oC with R² (0.089). At a temperature of 30^oC, Oswin, GAB, Henderson, Chung Pfost, and Halsey gave good fit.