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Title: An investigation into the antioxidant activity of a cider yeast extract with the aim of process optimisation
Author: Jumbu, Neeraj
ISNI:       0000 0004 5351 1824
Awarding Body: University of Birmingham
Current Institution: University of Birmingham
Date of Award: 2014
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Cider and/or beer lees has normally either been used as low cost animal feed or been disposed of at great cost. A higher value use for the yeast was therefore sought. This has been developed with the use of environmentally friendly subcritical water extraction. Results have shown that the extract contains anti-oxidant activity using two separate anti-oxidant assays, with a large improvement in activity above a process temperature of 200 °C. This is due in large part to an increase in the concentration of phenolic compounds in the extract. As a result of this, a refined extract was produced using supercritical CO2 that improved anti-oxidant activity compared to the crude extract. The anti-oxidant activity of the 200°C and refined extract has also been demonstrated using the comet assay in cells with the performance of the extracts being comparable to that of Trolox. The rheological stability of a number of cosmetic formulations incorporating the extract has also been tested with 2 of the 4 formulations being stable. However, colour change issues have been observed with all four formulations tested. Overall, a novel and biologically effective extract has been produced using data from anti-oxidant assays to improve activity of the extract.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: T Technology (General) ; TP Chemical technology