KNUSTSpace >
Theses / Dissertations >
College of Science >

Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/5336

Title: Evaluation of Free-Radical Quenching Properties and Determination of Ic50 of some edible fruits and Vegetables sold on the Ghanaian market
Authors: Yirenkyi, Andrews Kwame Agyemang
Issue Date: 2-Dec-2013
Abstract: Fruits and vegetables are good for the human system. From studies fruits and vegetables are known to have the ability to prevent diseases and sickness. This is due to the free radical scavenging abilities of the antioxidants in them. This study was carried out to investigate the free radical scavenging abilities of some selected fruits and vegetables: Asiminia triloba, Mangifera indica, Persea americana, Solanum torvum, Xanthosoma colocasia, Allium ascalonicum Linn and to determine its minimum Inhibitory concentration (IC50). The total antioxidant capacity (TAC), total phenol content (TAC), reducing power potential and the DPPH scavenging assays of the methanolic extracts of samples were determined. The result for the total antioxidant capacity of the measured concentration (0.1 - 0.3 mg/ml) had mangifera indica showing the highest capacity with 0.274 mg Ascorbic Acid Equivalence (AAE) with the lowest being 0.085 mg AAE for Xanthosoma colocasia. Mangifera indica again showed the highest total phenol content with 0.348 mg Tannic Acid Equivalence (TAE). There was a perfect correlation between Total Antioxidant Capacity (TAC) and Total phenol content (TPC) of the extracts with r =1 and p < 0.0001 for all the correlation graphs. Highest absorbance was shown at concentration 0.1 mg/ml by solanum torvum with 0.1272 and mangifera indica with 1.4967 at 3 mg/ml with a Gallic Acid Equivalence (GAE) of 0.013919 mg GAE and 0.193267 mg GAE respectively for the ferric reducing antioxidant power assay (FRAP). Solanum torvum showed the highest scavenging ability with IC50 of 1.0676 mg GAE and Persea americana with 2.5759 GAE mg as the minimum gallic equivalence concentration that can reduce free radicals in the system. Percentage scavenging ability was highest for Asiminia triloba with 80.75% and lowest for 34.25% all at the concentration of 3 mg/ml. This is the highest percentage of free radicals that can be reduced at the experimental concentrations. The FT-IR spectroscopy (800 – 3600 cm-1) was used to confirm the presence of phenol groups (3300 – 3600 cm-1), benzene rings (1500 – 1700 cm-1) and the antioxidant activity of the sample extracts. Peaks at various band lengths were obtained in both the functional group and fingerprint region to confirm the total phenols of the samples under study.
Description: A Thesis submitted to the Department of Chemistry, Kwame Nkrumah University of Science and Technology in partial fulfilment of the requirements for the degree of MASTER OF PHILOSOPHY (M Phil) IN ANALYTICAL CHEMISTRY Department of Chemistry College of Science AUGUST 2013
URI: http://hdl.handle.net/123456789/5336
Appears in Collections:College of Science

Files in This Item:

File Description SizeFormat
Andrews Yirenkyi Agyemang (thesis).docx final for printng.pdf1.87 MBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


Valid XHTML 1.0! DSpace Software Copyright © 2002-2010  Duraspace - Feedback