Abstract: In order to obtain the maximum extraction yield of capsaicin, extraction parameters such as pH, ethanol concentration, extraction time and temperature were optimized using an L9(34) orthogonal array design. Capsaicin content was determined by GC-MS. The results showed that capsaicin was decomposed at temperatures above 50 ℃. Slightly alkaline pH values were beneficial to the extraction of capsaicin. The extraction parameters could be ranked in decreasing order of importance in their effect on the extraction yield of capsaicin as follows: temperature > ethanol concentration > pH > extraction time. The optimal conditions of pH, ethanol concentration, temperature and extraction time were 8, 70%, 50 ℃ and 3.5 h, respectively. Under these conditions, the average extraction yield of capsaicin were 6.812 mg/g (n = 4).

Key words: capsaicin, hot pepper (Capsicum frutescens L.), alkaline extraction, gas chromatography-mass spectrometry (GC-MS)