Drying characteristics of unshelled kernels of candle nuts

Candle nuts are cultivated in approximately 170 000 ha. in Indonesia, and yield around 140 000 tons of fruit per year. Prior to removing the shells, drying is an important process in the post-harvesting practice of candle nuts to obtain kernels as the final products. This paper gives a brief description of the efforts to obtain the basic drying characteristics of candle nuts, which is a pre-requisite for dryer design. The measurements were taken for unshelled kernels of candle nuts, for both fresh and stored samples, at temperatures of 40, 50, and 60 °C and drying air velocity of 0.67 m/s and 1 m/s using a forced convection dryer. The total drying time was substantially reduced with an increase in temperature, and the effect of drying air velocity was relatively small. Page’s model adequately describes the drying behavior for the range of temperatures measured. The dependence of the drying constant on air temperature can be described by the Arrhenius model.