Determination of capsaicinoids in peppers by microwave assisted extraction–high performance liquid chromatography with fluorescence detection英文电子书.pdf

Analytica Chimica Acta 578 (2006) 227–233 Determination of capsaicinoids in peppers by microwave-assisted extraction–high-performance liquid chromatography with fluorescence detection Gerardo F. Barbero, Miguel Palma ∗, Carmelo G. Barroso Grupo de Investigaci´on Qu´ımico Anal´ıtica del Vino y Productos Agroalimentarios, Departamento de Qu´ımica Analitica, Facultad de Ciencias, Universidad de C´adiz, Apartado 40, 11510 Puerto Real, C´adiz, Spain Received 30 March 2006; received in revised form 27 June 2006; accepted 28 June 2006 Available online 4 July 2006 Abstract A new method has been developed for the extraction of capsaicinoids (nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin and homodihydrocapsaicin) in peppers employing microwave-assisted extraction. The parameters studied are: extraction solvent (methanol, ethanol, acetone, ethyl acetate and water), temperature (50–200 ◦C), sample quantity (0.1–1 g), volume of solvent (15–50 mL) and the extraction time (5–20 min). The results found for the optimum conditions are: 125 ◦C as extraction temperature, 25 mL of solvent, 0.5 g of freshly triturated peppers and extraction for 5 min, employing 100% ethanol as solvent. The capsaicinoids obtained were stable under the optimised extraction conditions. The resulting method presents a high degree of reproducibility (R.S.D. 6%). © 2006 Elsevier B.V. All rights reserved. Keywords: Microwave-assisted extraction; Capsaicinoids; Peppers 1. Introduction Many techniques for the extraction of capsaicinoids from