A Novel Non-Intrusive Imaging Technique to Quantify Shrinkage of Elephant Foot Yam During Convective Drying

The current work discusses the design and development of a novel convective drying system which predicts both the drying and the shrinkage characteristics of any food material simultaneously at different drying air velocities and temperatures. In the present work, the shrinkage characteristics of a cylindrical-shaped Elephant Foot Yam (EFY) food sample are determined by a non-intrusive imaging method. The top- and side-view images of the EFY sample at drying air velocities of 2, 4, and 6 m/s and at air temperatures of 313, 323, and 333 K are captured and processed using an in-house image processing code. The shrinkage characteristics reveal the nature of the transient variation of the bulk volume and the bulk density of the EFY with its moisture content. Suitable correlations developed for the bulk volume of the EFY suggest that it varies quadratically with moisture content, whereas the bulk density varies exponentially with moisture content for all drying conditions. It was also found that the developed methodology can predict the transient volume and density of the drying EFY sample for different cases of air velocities and temperature with significant accuracies.