Isolation of individual hop iso-α-acids stereoisomers by β-cyclodextrin

Khatib, Alfi and Wilson, Erica G. and Supardi, Moses and Verpoorte, Robert (2010) Isolation of individual hop iso-α-acids stereoisomers by β-cyclodextrin. Food Chemistry, 119 (1). pp. 354-357. ISSN 0308-8146

PDF (Full text) - Published Version Restricted to Repository staff only Download (332kB) | Request a copy

Abstract

Individual iso-α-acids that are responsible for the bitter taste of beer need to be isolated because these acids are required as reference standards in quantitative analysis and when studying the parameters which effect the quality of beer. However, these pure compounds are very expensive, due to inefficient isolation methods. In this study a new isolation method has been developed, in order to reduce the isolation cost. β-Cyclodextrin has been used for the isolation of trans- and cis-iso-α-acids. The separation from the mixture of stereoisomers was achieved by complexation, using ethanol:water (1:2, v/v) as a solvent at a temperature of 50 °C for 30 min. The molar ratio of iso-α-acids sample to β-cyclodextrin for complexation was 1:1. Precipitation time varied between 9 h and 2 days, depending on the iso-α-acid. Release of the guest from the cyclodextrin complex was successfully accomplished by elution with methanol.

Item Type:	Article (Journal)
Additional Information:	6915/33381
Uncontrolled Keywords:	Hop; Cyclodextrin; Beer; Bitter acids; Iso-α-acids; Centrifugal partition chromatography
Subjects:	Q Science > QD Chemistry
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Pharmacy > Department of Pharmaceutical Chemistry
Depositing User:	Dr. Alfi Khatib
Date Deposited:	16 Dec 2013 14:12
Last Modified:	16 Dec 2013 14:12
URI:	http://irep.iium.edu.my/id/eprint/33381

Actions (login required)

View Item