SOURCE:

Faculty: Engineering
Department: Mechanical Engineering

CONTRIBUTORS:

Gbasouzor, A.I;
Omenyi, S.N;

ABSTRACT:

This research presents the results of convective drying of ginger rhizomes under blanched, unblanched, peeled and unpeeled conditions using the ARS-0680 environmental chambers for the drying process and TD1002A - linear heat conduction experimental equipment to measure the thermal conductivities of the ginger at six temperature levels ranging from 10 - 60°C and drying times of 2 and 24 hours. The drying curves were drawn using the moisture and conductivity data. The drying rate at higher drying times (24 hours) was 0.889/oC and 0.4437/oC for 2 hours drying, giving 50% in moisture reduction rate. Whereas the initial moisture content was 95.12%, it reduced to 59.33% for the 24 hour-drying time. The result of this study shows that the lowest moisture content (5.98%) was obtained for unpeeled ginger while the highest was the blanched (9.04%) all for 24 hour-drying and at 60 oC. The average moisture content for 2 hours drying at 60°C was 70.6% while for 24 hours drying; it was an average of 7.55%. which is close to the target of 4 – 7% desired for this research. Though our results made our target, they are in line with the literature results that recommend moisture content of 7 – 12%. These show the superiority of higher temperature drying and the use of the convective drying method. The thermal conductivity for 24 hour-dried ginger at 60°C approximates to the thermal conductivity of dried ginger and it is 0.050 W/mK on the average. The unpeeled ginger gave the lowest value of 0.046 W/mK while the unblanched ginger gave the highest value of 0.055 W/mK. For 2 hours of drying, the average value was 0.079 W/mK while the unblancehd ginger gave the lowest (0.076 W/mK) while the blanched the highest (0.084 W/mK).