Optimization of the water extraction process on the total phenolic content from Labisia pumila

Abstract

Labisia pumila is one of the most widely used medicinal herbs among women in Southeast Asia.There is an increasing demand force for this herb in pharmaceutical and food industries. Most of these products are registered without knowing the level of bioactivity in the extracts and not in standardised form. Non-standardized extract is perceived as a low-quality herbal product, hence lowering its market value. Therefore, this study aimed to standardize the optimal water extraction conditions for maximum total phenolic content (TPC) of L. pumila. In this study, Response Surface Methodology (RSM) was used to optimize the extraction process of TPC from L. pumila. Dried whole plant of L. pumila was extracted in water as solvent at different temperatures, times, and solid to water ratios that have been identified to be significantly affecting the recovery of TPC. A Box-Behnken design was used to investigate the effects of three independent variables that were coded at three levels consisted of 30 experimental points using decoction method. A second-order polynomial model was used for predicting the response. Regression analysis showed that more than 91.99 % of the variation was explained by the models. Results identified temperature as the most significant (p<0.05) factor affecting the TPC. The optimal conditions obtained from RSM were 60ᴼC for the temperature, 2.67 hours for the extraction time and 1:10 for the solid to water ratio. Under these optimal conditions, the response value of the experimental values agreed with the predicted value of TPC. In conclusion, the present study has succesfully standardized optimal temperature, time and solid-water ratio of L. pumila water extraction process for high TPC.