THERMAL-PROPERTIES OF CASSAVA, YAM AND PLANTAIN

Thermal conductivity (k), specific heat capacity (c(p)) and thermal di ffusivity (d) are important properties in modeling, simulation and con trol of various food processing operations. In this study, these prope rties were determined for the following crops: cassava root, yam tuber and plantain fruit. k was measured using a line heat source probe at moisture contents (M) in the range 14-79% wet basis and temperatures n ear 30 degrees C. The results ranged form 0.16 to 0.57 W m(-1) degrees C-1 for cassava (M = 18-70%), 0.16 to 0.60 W m(-1) degrees C-1 for ya m (M = 0.16-79%), and 0.13 to 0.45 W m(-1) degrees C-1 for plantain (M = 14-57%). c(p) was measured with a differential scanning calorimeter between 36 degrees and 51 degrees C in the M range 10-68%. It increas ed with M and temperature, and varied from 1.636 to 3.26 kJ kg(-1) deg rees C-1. d of each crop was calculated using k and c(p) data predicte d by empirical models that were derived from the experimental data. Th e results were close to those given in the literature for similar food s. (C) 1998 Elsevier Science Limited. All rights reserved.