investigation into the thin layer drying models of nigerian popcorn varieties

Abstract

Drying kinetics of three popcorn varieties (Pin, Deep and Light yellow) was investigated. The popcorn kernels initially conditioned to 25% moisture content were dried in a bench scale rotary drier to 14% moisture content at various air flow rates (0.83, 1.397, 2.79 m/s) and temperatures (50oC, 60oC, 70oC and 80oC). Falling rate drying period was observed for the three popcorn varieties with Pin popcorn having the highest drying rate. Eight drying models were used to determine the thin layer drying kinetics. The Page equation, Two term model, Modified Page were found the best to describe the thin layer drying of Pin, Light yellow and Deep yellow popcorn, but the newly proposed model serve as a general model which best describe the drying kinetics of all the three popcorn varieties, with high correlation coefficient. The drying behaviour of the three kernels was found to be largely dependent on changes in temperature and air velocity.