Characteristics and Empirical Modelling of Extract from Hibiscus sabdariffa Using Supercritical CO2 Extraction with Ethanol-Water as Modifier

• Main Authors: Idham, Z., Putra, N.R., Idrus, N.F.M., Mili, N., Ruslan, M.S.H., Rasidek, N.A.M., Yunus, M.A.C.
• Format: Article
• Published: Springer Science and Business Media Deutschland GmbH 2021
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111357274&doi=10.1007%2f978-981-16-0742-4_26&partnerID=40&md5=e6c996cb9759345b712f3511d15cfc3d; http://eprints.utp.edu.my/29484/

The main constituents of the extract from Hibiscus sabdariffa calyces are anthocyanins which gave intense natural red colorant and commonly used for centuries for therapeutic purposes. Supercritical carbon dioxide (SC-CO2) technique could produce high-quality extracts from plant materials as it can exploit the non-toxic character and the gas�liquid properties of the SC-CO2. This research aimed to characterise the colour and the pattern of Hibiscus sabdariffa SC-CO2 extraction. The colour was evaluated by using a CIELAB method meanwhile the presence of anthocyanins in the red colour extract was confirmed by High-Performance Liquid Chromatograph (HPLC). Two types of empirical models (Modified Brunner�s and Esquivel�s models) were used to describe the extracts obtained at series of operational parameters (i.e. pressure and temperature) at 7.5 and 10 of modifier ratio, with a total solvent flow rate of 4 ml/min. Both models were analysed using a non-linear regression method. The modified Brunner�s model shows the best agreement between experimental and model calculated data with the lowest AARD of 1.30 at 70 °C, 10 MPa, and 10 modifier ratio. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.