Evaluating Some Empirical Models for Predicting Water Absorption in African Breadfruit (Treculia Africana) Seeds

Abstract

Water absorption process during soaking of African breadfruit (ABF) seeds was studied at five typical soaking temperatures, ranging between 30 and 70°C. The progress of water absorption by the seeds followed an exponential increase with increase in temperature. The experimental data were fitted to three empirical equations. All the equations were able to explain over 90% of the experimental data. The predicted water absorption capacity (M e ), which ranged between 68 and 92/100 g dry solid were not significantly affected by temperature changes (p > 0.05) while the time to achieve maximum water absorption capacity ranged between 9 and 140 h. The water absorption rate constant in Singh–Kulshrestha's model was more sensitive to temperature changes than from the others. By applying Arrhenius equation, it was shown that water absorption at 30–70°C was the predominant process responsible for the changes in mass of ABF seeds. The differences in the experimental and predicted data from the three models were compared to evaluate their goodness of fit. The chi-square and the root mean square deviation (RMSD) showed that Singh–Kulshrestha and Pilosof's models described better the moisture variation in soaked ABF seeds with time. In terms of residual moisture plots, Singh–Kulshrestha's model gave a more random distribution at all soaking temperatures, making it a better fitting equation.