master philipe

Extraction of capsaicinoids from malagueta pepper (Capsicum frutescens L.) using supercritical CO2 and ultrasound

Author: Philipe dos Santos (2013)

Abstract: The supercritical fluid extraction technology came as an alternative to traditional methods of extraction and fractionation of active compounds. The capacity of a supercritical fluid extraction unit is changed with the application of combined techniques, for example, using different co-solvents and ultrasonic waves. The ultrasonic technology is based on high frequency ultrasonic waves formation capable of causing cavitations and disrupting the cell walls of vegetable matrix, favoring the penetration of solvent and enhancing mass transfer, thus increasing the extraction yield. The objective of this study was to obtain extracts of malagueta pepper (Capsicum frutescens L.) using supercritical fluid extraction (SFE) assisted by ultrasound. The raw material used was dried (5% w. b.) and triturated malagueta pepper. To study the influence of ultrasonic waves in the extraction rate, SFE experiments were performed with and without ultrasound, with powers and irradiations times from 150 to 360 W, and from 60 to 280 minutes, respectively. The conditions of temperature and pressure of supercritical carbon dioxide were 40 ± 3°C and 15 ± 0.5 MPa, respectively. The CO2 mass flow rate was fixed at 0.5 ± 0.1 kg/h. The extraction kinetics was performed in the best conditions of ultrasonic power ultrasonic in different particle diameters. The results indicated that the yield of oleoresin increased 77% when ultrasound waves were applied. The influence of the application of ultrasonic waves was not significant in the capsaicinoids and phenolics profiles. The best ultrasound-assisted extraction conditions were at 360 W (power) for 60 minutes (irradiation). The effect of ultrasound was verified on extraction rate and the solid and fluid phase mass transfer coefficient. The Sovová (1994) model was adequate to predict the extraction kinetics, but overall extraction yield values obtained in experiments assisted by ultrasound must be used. The images obtained by field emission scanning electron microscopy (FESEM) showed a disturbance in the vegetable matrix when ultrasound waves were applied.