Abstract
The pH had a more significant effect on the antioxidant activity of Trolox than α-tocopherol in corn oil emulsified with Tween 20 at 60 °C. Although with increasing pH the oxidative stability of corn oil emulsions decreased, the antioxidant activity of α-tocopherol increased. Initially, Trolox and α-tocopherol were similar in inhibiting hydroperoxide formation with or without phosphate buffers at pH 3-7, but at later stages α-tocopherol was more effective than Trolox at pH 3, 4, 5, and 7 but not at pH 6. In contrast, α-tocopherol inhibited hexanal formation better than Trolox during the entire oxidation period. Trolox was more stable than α-tocopherol in bulk corn oil but less stable in Tween 20 solutions at different pH. Both antioxídants in Tween 20 solutions were most stable at pH 3 and least stable at pH 7. Although more Trolox partitioned into the oil phase and the oil-water interfaces at pH 3-4, its antioxidant activity was lower than at pH 5-6. The overall antioxidant activities of α-tocopherol and Trolox depend on their hydrogen-donating ability, relative stability, and distribution in emulsions.
Original language | English (US) |
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Pages (from-to) | 2496-2502 |
Number of pages | 7 |
Journal | Journal of Agricultural and Food Chemistry |
Volume | 44 |
Issue number | 9 |
State | Published - Sep 1996 |
Keywords
- α-tocopherol
- Antioxidant mechanism
- Antioxidants
- Corn oil triglycerides
- Emulsion
- Hexanal
- Hydroperoxides
- Interfacial oxidation
- Oxidative stability
- Partition coefficient
- Trolox
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Food Science
- Chemistry (miscellaneous)