Optimization of capsaicin purification from Capsicum frutescens Linn. with column chromatography using Taguchi design

Abstract

Capsaicin is a major capsaicinoids presented in hot chilies and peppers. It is widely used in pharmacology and clinical applications because of its properties such as anti-mutagen, anti-tumor and antioxidant. Therefore, the optimum capsaicinoids extraction was studied. Two different techniques, comparing with traditional soxhlet method, microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE), were used to extract the capsaicinoids from dried chilies (Capsicum frutescens Linn.). The electrical power (90-600W) and the extraction time (5-20min) were investigated for MAE while those of 5-30min were examined for UAE. The optimum method for capsaicinoids extraction was UAE which gave the highest amount of capsaicinoids at 4.01mg/g of dried chili. Consequently, the Taguchi's experiment design methodology was performed in order to identify the optimum capsaicin separation condition in column chromatography. Three factors including mobile phase ratio (ethanol:water), bed height and flow rate of mobile phase were analyzed. The mixed-level orthogonal array design, L16 (21×42) matrix was employed to access the capsaicin purity. The optimum conditions were 40% of ethanol as mobile phase, 25cm of bed height with the flow rate of mobile phase of 2.5ml/min. It was also found that the mobile phase ratio was the most important factor in capsaicin separation. © 2012 Elsevier B.V.