ABSTRACT

Natural base products are being sought for these days because they have no side effect when taken accordingly. Also, there is an interest in the production of functional, high value natural products without chemical changes and residue of solvent or additives. This change in consumer preference raises the demand greatly with variety of products ranging from saponin.

In this study, the yield level of saponin in ginger was optimized using three variable central composite design (CCD) coupled with response surface methodology (RSM). The variables investigated were mass of solid, extraction time, extraction temperature. The CCD was used to generate a statistical model for predicting the optimal levels of the variables.

Results obtained from analysis of variance (ANOVA) showed that the model was statiscally significant (p<0.0001) with a high coefficient of determination (0.97). Thus, after evaluating the model graphs the combinations suggested the numerical optimization conditions to be; mass of 4.22 g,extraction time of 127.20 minutes, extraction temperature of 84.04 ^oC and saponin yield of 40.90 %.Validation of the statistical model indicated no significant difference between the experimental observations and model predictions.The FT-IR spectrum showed 17 peaks, the IR spectral showed important absorption bands at 2354.80 attributed to O-H stretching, 1423.56 assigned to C=C stretching and 1155.24 assigned to C-O stretching. Those peaks clearly showed that saponin was extracted from ginger.