Jumbu, Neeraj (2014). An investigation into the antioxidant activity of a cider yeast extract with the aim of process optimisation. University of Birmingham. Ph.D.
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Jumbu14PhD.pdf
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Abstract
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.
Type of Work: | Thesis (Doctorates > Ph.D.) | |||||||||
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Award Type: | Doctorates > Ph.D. | |||||||||
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College/Faculty: | Colleges (2008 onwards) > College of Engineering & Physical Sciences | |||||||||
School or Department: | School of Chemical Engineering | |||||||||
Funders: | None/not applicable | |||||||||
Subjects: | T Technology > T Technology (General) T Technology > TP Chemical technology |
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URI: | http://etheses.bham.ac.uk/id/eprint/4984 |
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