Correlation between total phenolics and mineral content with antioxidant activity and determination of bioactive compounds in various local bananas (musa sp.)
| dc.contributor.author | Md Yusoff, Nor Adlin | |
| dc.date.accessioned | 2015-08-25T07:38:51Z | |
| dc.date.available | 2015-08-25T07:38:51Z | |
| dc.date.issued | 2008 | |
| dc.description.abstract | This study was designated to evaluate the correlation between total phenolics and mineral content with antioxidant activity in various extracts of pulps and peels of eight local banana cultivars, Musa sp. In addition, identification and characterization of the bioactive compounds was also carried out. Samples were extracted using three different extraction procedures. The total phenolic contents were measured by Folin - Ciocalteu colorimetric method, whereas antioxidant activity was estimated by using 2, 2- diphenyl- I - picrylhydrazyl (DPPH) free radical scavenging assay. These extracts exhibited a wide range of total phenolic content and antioxidant activity varying from I2.47 ± O.I2 to I75.47 ± 0.31 mgGAE/g dry extract and IO.I2 ± 0.64% to 80.04 ± 0.66%, respectively at 2000 Jlg/ml concentration. Generally, peel extracts exhibited higher total phenolic content and stronger antioxidant activity than pulp extracts. Among all extracts, the dried banana samples extracted with various solvent polarities using Soxhlet apparatus showed the highest total phenolic content and the most potent antioxidant activity. Significant and positive linear correlation were found between total phenolic content and antioxidant activity (r2 = 0.6073, p < 0.000 I), indicating that phenolics were the major antioxidant constituents in the extracts. Meanwhile, the Rr values and colour on thin layer chromatography plates developed by various solvent systems, mass spectral and ultraviolet spectrum were used to identity and characterize the bioactive compounds. A total two bioactive phenolic compounds were identified, which were 3, 5, 8 droxymyricetin and ferulic acid. Total phenolic content of both bioactivc compounds were 395.07 ± 0.12 mg GAEl g dry extract and 175.87 ± 0.12 mg GAEl g dry extract, respectively. Meanwhile, the percentage of antioxidant activity were 86.15 ± 0.05% (3, 5, 8 - trimethyl 6, 8 dihydromyricetin) and 27.42 ± 1.16% (ferulic acid). The presence of these compounds in the banana peels has never been reported. The content of macrominerals (Na, K, Ca and Mg) and microminerals (Fe, Cu, Zn and Cu) in local bananas has been determined by atomic absorption spectrometer (AAS) and atomic emission spectrometer (AES). Potassium was the most significant mineral element presents in both banana pulps and peels with an estimated value of 295.68-463.57 mg/1 00 g fresh weight and I 071.20- 1361.56 mg/1 00 g fresh weight, respectively. Based on the obtained results, bananas are shown to contribute to the recommended daily requirements suggested by US - RDA for K, Mg, Fe and Zn. Overall, the relative order of concentration of macrominerals both in pulps and peels was K > Mg > Na > Ca, while the decrease order of microminerals concentration was Mn > Fe > Zn > Cu. In addition, mineral content was found as not significantly correlate with their antioxidant activity with the exception of K and Mn which form a moderate correlation with antioxidant activity of water extracts. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/1119 | |
| dc.language.iso | en | en_US |
| dc.subject | Total phenolics | en_US |
| dc.subject | Antioxidant activity | en_US |
| dc.subject | Various local bananas (musa sp.) | en_US |
| dc.title | Correlation between total phenolics and mineral content with antioxidant activity and determination of bioactive compounds in various local bananas (musa sp.) | en_US |
| dc.type | Thesis | en_US |
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