Affiliations 

  • 1 Universiti Selangor
MyJurnal

Abstract

This study investigated the use of ultrasound-assisted extraction (UAE) and agitated-bed extraction (ABE) to improve extraction efficiency of dyes from exocarp and mesocarp of Cocos nucifera. The UAE method was carried out at a frequency of 37 kHz and power of 150 W at 30°C for 1 hour and ABE technique was performed at 30°C for 24 hours at the agitation of 150 rpm. The effects of different solvent types (methanol, ethanol and acetone) and the different percentage of solvent (20%-70%) were determined. The results showed although the colourant yield increased with the increase of solvent concentration up to 60%, statistic value indicated no significant difference (p > 0.05) for the value of yield using solvent range from 20% to 70% for both UAE and ABE methods. Therefore, the solvent concentration of 20% was selected as the optimum concentration for each type of solvent used for both ABE and UAE methods. In comparison, higher extraction yields were achieved by UAE method where the optimal yield of the colourant of the mesocarp was 7.6% using acetone as solvent and the exocarp yielded about 6.4% using acetone or methanol. The recovery of natural colourant using ultrasound was found to be highly dependent on the type of solvents (acetone > methanol > ethanol) for both mesocarp and exocarp. The present study suggests that UAE method should be employed for hauling out colouring materials from exocarp and mesocarp due to its effectiveness in terms of time and economical usage of solvent.