Optimization of reflux extraction for cat’s whiskers leaves extract using response surface methodology

Abstract

Cat's whiskers (Orthosiphon stamineus) is a medicinal plant which comprises several dynamic pharmacological properties such as anti-inflammatory, antioxidant and antibacterial. In small and medium-scale industries, conventional reflux extraction method is favored as compared to other non-conventional extraction methods due to cost effectiveness and simple operating procedures. In this study, response surface methodology (RSM) was applied to optimize the reflux conditions for extraction of cat's whiskers leaves in order to achieve a high content of antioxidant activity in the extracts. Central composite experimental design (CCD) with three factors and three levels was employed to consider the effects of the operation conditions. Antioxidant activity of the extracts were based on free radical scavenging activity (DPPH assay) and were analyzed using a UV-Vis spectrophotometer. Based on RSM, the antioxidant activity could be maximized when the operation conditions were 125 µm for particle size, 1.5:20 for sample-to-solvent ratio, and 2 h for extraction time. Under these optimal conditions, the predicted value of the antioxidant activity was compared with the actual, and the mean error was 0.46%. This indicates the suitability of the model for optimizing the conditions for the reflux extraction of cat's whiskers leaves.

Optimization of Reflux Extraction for Caesalpinia Sappan Linn. Wood by Using Response Surface Methodology

“…The reflux extraction is a conventional method that has been favorable in industries because it is economical friendly, not complex, and easy to handle [4], [7], [8], [9]. It operates at the boiling point temperature of the solvent with reiteration of solvent evaporation that condense back to the liquid state with the aids of condenser at selected time without deprivation of solvent.…”