Thesis (M.Eng.)--Chulalongkorn University, 2006

To presents the use of ultrasound-assisted extraction (UAE) to extract capsaicinoids from dried ground chili fruits, capsicum frutescens and compared the results with a hot maceration method, in the aspect of their conveniences and effectiveness. Capsaicinoids were extracted by the indirect sonication in ultrasonic bath at fixed frequency 35 kHz. The studied parameters were temperature, type of solvents (acetone and 50-95% v/v ethanol) and ratio of sovent: crude chili pepper. The capsacinoid concentration ws analyzed by high performance liquid chromatography. It was found that the optimized procedure for the operation employed 1 gram of ground dried chili fruit per 5 mL of 95% (v/v) ethanol at 45 ํC and 180 minutes of extraction time. The recovery of capsaicinoids ws 84.8%. This operating condition was applied for the ultrasonic extraction in pilot scale. At the fixed frequency of 26 kHz and 70 kHz, the recovery of capsaicinoids was 76.4 and 69.6%, respectively. Although the recovery of capsaicinoids was slightly lower than that of the industrial hot maceration process (81.8% recovery), the ultrasonic extraction was more convenient for the operation, gave a signification reduction in extraction time, could be carried out at lower temperature and the obtained product contained less impurities.