AN IMPROVED THERMAL-CONDUCTIVITY PREDICTION MODEL FOR FRUITS AND VEGETABLES AS A FUNCTION OF TEMPERATURE, WATER-CONTENT AND POROSITY

An improved general thermal conductivity prediction model has been dev eloped for fruits and vegetables as a function of water content porosi ty and temperature. Thermal conductivity values of apple, peal; corn s tarch, raisin and potato were used to develop the model using 164 data points obtained from the literature. Raisin has the maximum mean perc ent deviation of 15.1% (standard deviation 10.1) and pear gave minimum mean percent deviation of 6.8% (standard deviation 7.3). The errors f or predicting the thermal conductivity using this improved model for f ruits and vegetables are therefore within the range of 6.8-15.1%, whic h is acceptable for general engineering practice. (C) 1997 Elsevier Sc ience Limited.