Subcritical water extraction (SWE) of Zingiber zerumbet using two level full factorial design

Zingiber zerumbet was reported to has chemo preventive effects and was suggested as one of the therapeutic treatments for cancer. In this study, Z. zerumbet was extracted using subcritical water extraction (SWE) by employing two level full factorial design. 2(k) full factorial design was employed using 18 runs with 10 repeats in central points. The independent variables factors were temperature (100-150 degrees C), time (10-30 minutes) and material ratio (1: 10 and 1: 20 g/ml) for the evaluation of highest zerumbone concentration and overall yield of extracted Z. zerumbet. Effects of extraction temperature and time were found to be significant on all responses with p-value <0.05. However, the material ratio only gave significant effect on the zerumbone concentration and less significant on the yield. In addition, the value of curvature was found to be significant, thus indicating the relation between the independent variables and the response was linear. Therefore, it was found that the concentration of zerumbone and yield from Z. zerumbet extracted by SWE were significantly affected by temperature and time of extraction.