Case study: Statistical analysis of eurycomanone yield using a full factorial design

Abstract

Eurycoma longifolia, also known as Tongkat Ali, is popular in Asia due to its aphrodisiac properties. The root extract also exhibits cytotoxic, anti-ulcer, antitumour, antipyretic, antischistosomal and antimalarial activities. This work focuses on the development of experimental design to find a set of optimum process variables for water extraction of Eurycoma longifolia roots. A two level full factorial design has been successfully employed to generate a linear regression model for the process variables (solvent to raw material ratio, extraction time and particle size) with eurycomanone yield as the response. The regression model was statistically significant with R2 of 0.98; the residuals of the model are normally distributed. The factor that presented has the strongest influence on yield was solvent-to-raw material ratio, followed by extraction time. The interaction effect between ratio and particle size on eurycomanone yield was also significant in this model. The validity of this analysis is limited to water extraction at 100°C with an agitation rate of 400rpm.