Analytical Approach for Predicting Water Loss in Tubers during Convective Drying: A Case Study on Sweet Potato

Abstract

In this article, the aim was to develop a method using an analytical approach to determine the reduced water content of sweet potato samples during convective drying. The prediction was made based on a study of the evolution of the drying constant of Newton's model as a function of the size of sweet potato samples at a temperature of 70 ℃. Chi-square  and coefficient of determination   were used as indicators of prediction and modeling quality. The study carried out on sweet potato samples cut into cubic shapes with 0.5, 1, 1.5, 2, 2.5 and 3 cm edges showed that the evolution of the drying kinetic constant is best expressed mathematically as a power with .  Examination of the reliability of the prediction method carried out on samples of cubic-shaped sweet potatoes with an edge of 1.75 cm showed good results and accuracy . The one carried out on spherical; cylindrical; parallelepiped sweet potato samples of characteristic diameter  showed that the prediction was more accurate with sweet potato samples cut in the spherical form. To check whether the results obtained from the analytical approach applied to sweet potato samples could be transposed to other tubers, cassava, yam and taro samples with a 3 cm cube were cut. The comparative study between the experimental and predicted reduced water contents showed that the results obtained by the method on sweet potato were transposable to yam and taro, with good quality indices. On the other hand, for cassava, the predicted results needed adjustment with regard to quality indices.