Abstract:
As wine production increases to meet growing consumer demands, this results in large amounts of grape pomace. There are limitations to the current practices of managing this waste material and the concerns about its impact on the environment are growing. Due to this, there is a need to find alternative solutions towards utilising this waste material. This thesis project investigates the strategy of using grape pomace as a source of bioactive flavonoids which can then be derivatised into more lipophilic compounds to enhance their health-promoting potential. The work to achieve this began with the preliminary small scale solid-liquid extraction work on Pinot noir pomace to determine the ideal solvent systems that would give an extract with higher content of desired bioactive flavonoids. Synthetic studies were then conducted to afford a series of model lipophilic luteolin and quercetin derivatives. These model lipophilic flavonoid derivatives were subjected to antiproliferative activity, radical scavenging activity and computed logP studies. The results of which were compared to their parent flavonoids to determine which of the lipophilic groups displayed enhanced health-promoting outcome. The findings from the above studies provided important information towards the final work of this project. A larger scale solid-liquid extraction work was conducted on Pinot noir pomace using the selected solvent system to obtain an extract with higher amounts of the desired bioactive flavonoids. This flavonoid-containing extract was derivatised with the selected derivatising agents. A preliminary bioactivity assessment on these derivatised extracts was attempted to determine whether the proposed strategy was suitable towards enhancing their health-promoting effects.
