Four casein-derived peptides fractions of varying hydrophobicity were obtained from á-chymotryptic digest of acid casein using hydrophobic interaction chromatography, termed fractions one through four (abbreviated, F1, F2, F3, and F4). Four standard methods involving alkoxyl, peroxyl, 2, 2-diphenyl-1-picrylhydrazl (DPPH), and 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ABTS•+ radicals, were used to measure antioxidative properties. While significantly superior efficacy was exhibited by F2 for all tests except against DPPH, no correlation between antioxidant efficacy and surface hydrophobicity was found. By using capillary electrophoresis and high performance liquid chromatography, the detection of aromatic chromophores by ultraviolet at 280 nm in the fractions revealed that F2 contained the highest concentration of aromatic amino acids and a unique peptide. Result from circular dichroism exhibited remaining residual structure in F2 compared with undigested casein. The F2 possesses a high potential to be used in food industry as a natural source of antioxidant with pronounced antioxidant capacity.
| Identifer | oai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-1694 |
| Date | 11 December 2015 |
| Creators | Shao, Wenjie |
| Publisher | Scholars Junction |
| Source Sets | Mississippi State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
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