ABSTRACT

 Long storage period and over drying deteriorate oleoresin content of ginger rhizome, hence, the need to process fresh ginger rhizomes. Ginger juice obtained from mechanical expression of fresh ginger rhizomes offers a value-added ginger product which will increase market opportunity for farmers. In this study, a motorized ginger juice expression machine was developed. The perfonnance of the machine was evaluated to determine the effects of moisture content of ginger and screw shaft speed on the expression efficiency, juice yield, expression loss and throughput capacity. Proximate composition of the ginger juice expressed and the residual waste were determined. Three levels of moisture content (wet basis) and three levels of screw shaft speed at two replications were used for the study. A 3 x 3 factorial experiment in a completely randomized experimental design was used. Data for the peiformance evaluation were U subjected to the analysis of variance for test of significance of the experimental factors and their interactions. The mean expression efficiency increased from 6.24 % to 83.12 % as the moisture content level increased from 71.87 % to 84.03 %, while it increased from 70.47 % to 87.02 % as the screw shaft speed decreased from 660 rpm to 420 rpm. The results showed that mean expression efficiency decreased with increase in screw shaft speed and with decrease in moisture content for the speed and moisture content ranges studied. Highest expression efficiency of 91.62 % and juice yield of 61.28 % were obtained at screw shaft speed of 420 rpm and at 7L87 % moisture content. The mean juice yield decreased with an increase in screw shaft speed and with a decrease in moisture content. The lowest expression loss of 11.69 % was obtained at 467 rpm and S 71.87 % moisture content. The machine had the highest throughput capacity of 9.47 kg/h U at 420 rpm. ANOVA results showed no significant effect of moisture content, speed and their interactions on all the performance indicators of the machine at