Optimal operating conditions of Eurycoma Longifolia extraction

Abstract

Eurycoma longifolia is known locally as Tongkat Ali and it is sold as a spray dried product. Its extract has shown medicinal benefits and it is considered as a valued product in pharmaceutical industries. The extraction yield depends on the extraction process parameters such as extraction time, agitation speed, solid to solvent ratio, temperature, particle type and type of solvent. Optimum extraction was focussed on eurycomanone, benzoic acid and gallic acid as the product of interests. Batch extraction experiments were conducted to study the effect of operating parameters on the extraction yield. The optimization of experimental results was performed using response surface methodology (RSM). A mathematical model for estimating the extraction yield has been developed and compared to results obtained experimentally. Comparative studies showed that results by mathematical model had shown good agreement with that of experimental results for the effect of extraction time, agitation speed and temperature on the extraction yield. Optimization of the simulated model was performed using genetic algorithm (GA). The optimum operating conditions obtained from eurycomanone were 100 oC, solid to solvent ratio of 1:24.5, 45 minutes and 398 rpm whilst 94.6 oC, 45 minutes and 360 rpm were obtained from GA. Similar tests on benzoic acid have shown 58.2 oC, solid to solvent ratio of 1:20, 44.7 minutes and 390 rpm were obtained from RSM whilst 46.5oC, 41 minutes and 398 rpm were obtained from GA. Finally, the optimum operating conditions for gallic acid using RSM were 85.7 oC, solid to solvent ratio of 1:20, 45 minutes and 390 rpm whilst 78 oC, 45 minutes and 400 rpm were obtained using GA. Relative error studies showed that only slight difference were observed for both RSM and GA.