eTheses Repository

Utility of critical fluids in extraction and encapsulation of polyphenolics from by-product of cider production

Ibrahim, Salis (2016)
Ph.D. thesis, University of Birmingham.

PDF (7Mb)Accepted Version


Efficacy of subcritical water in the recovery of the polyphenolic compounds from the apple pomace using a batch reactor system at 100-bar over a temperature range of 100-200oC for a residence time of 10–30 minutes was investigated. Organic solvent extractions using acetone and ethanol were carried out to serve as a baseline for comparison with the subcritical water extraction. Subcritical water was efficient in solubilising the apple pomace, and extracting polyphenolics with high antioxidant activity. Maximum solubilisation of the apple pomace was achieved at 145oC for 30 minutes and total phenolic content and antioxidant activity at 200oC. Solubilisation, ORAC activity and total phenolic content of subcritical water extract were 28.20g/100g DW, 99285μmol TE/g DW and 49.86mg/g GAE DW of apple pomace respectively, compared to 19.20g/100g DW, 6260.27 μmol TE/g DW and 21.70mg/g GAE DW of acetone extracts of apple pomace respectively. Protocatechuic aldehyde was identified for the first time only in the subcritical water extract and to date has not been identified in solvent extracts of cider apple pomace.
Encapsulation of polyphenolic s of subcritical water extract using spray drying was explored. Particles/powders formed were derived from the naturally occurring carbohydrate polymers co-extracted with polyphenols. Addition of HPβ-Cyclodextrins (SWE+ HPβ-CD) to the directly encapsulated powder (SWE) significantly reduced hygroscopicity and improved antioxidant activity.

Type of Work:Ph.D. thesis.
Supervisor(s):Grover, Liam
School/Faculty:Colleges (2008 onwards) > College of Engineering & Physical Sciences
Department:Chemical Engineering
Subjects:TP Chemical technology
Institution:University of Birmingham
ID Code:6861
This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder.
Export Reference As : ASCII + BibTeX + Dublin Core + EndNote + HTML + METS + MODS + OpenURL Object + Reference Manager + Refer + RefWorks
Share this item :
QR Code for this page

Repository Staff Only: item control page