Effect of pH on antioxidant activity of alpha-tocopherol and Trolox in oil-in-water emulsions

被引:86
作者
Huang, SW [1 ]
Frankel, EN [1 ]
Schwarz, K [1 ]
German, JB [1 ]
机构
[1] UNIV CALIF DAVIS,DEPT FOOD SCI & TECHNOL,DAVIS,CA 95616
关键词
antioxidants; a-tocopherol; Trolox; corn oil triglycerides; emulsion; antioxidant mechanism; stability;
D O I
10.1021/jf960262d
中图分类号
S [农业科学];
学科分类号
09 ;
摘要
The pH had a more significant effect on the antioxidant activity of Trolox than alpha-tocopherol in corn oil emulsified with Tween 20 at 60 degrees C. Although with increasing pH the oxidative stability of corn oil emulsions decreased, the antioxidant activity of alpha-tocopherol increased. Initially, Trolox and alpha-tocopherol were similar in inhibiting hydroperoxide formation with or without phosphate buffers at pH 3-7, but at later stages alpha-tocopherol was more effective than Trolox at pH 3, 4, 5, and 7 but not at pH 6. In contrast, alpha-tocopherol inhibited hexanal formation better than Trolox during the entire oxidation period. Trolox was more stable than alpha-tocopherol in bulk corn oil but less stable in Tween 20 solutions at different pH. Both antioxidants 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 alpha-tocopherol and Trolox depend on their hydrogen-donating ability, relative stability, and distribution in emulsions.
引用
收藏
页码:2496 / 2502
页数:7
相关论文
共 14 条
[1]   MEMBRANE PEROXIDATION - INHIBITING EFFECTS OF WATER-SOLUBLE ANTIOXIDANTS ON PHOSPHOLIPIDS OF DIFFERENT CHARGE TYPES [J].
BARCLAY, LRC ;
VINQVIST, MR .
FREE RADICAL BIOLOGY AND MEDICINE, 1994, 16 (06) :779-788
[2]   AUTOXIDATION OF BIOLOGICAL MOLECULES .4. MAXIMIZING THE ANTIOXIDANT ACTIVITY OF PHENOLS [J].
BURTON, GW ;
DOBA, T ;
GABE, EJ ;
HUGHES, L ;
LEE, FL ;
PRASAD, L ;
INGOLD, KU .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1985, 107 (24) :7053-7065
[3]   EFFECT OF EXPERIMENTAL FACTORS ON THE PROOXIDANT BEHAVIOR OF ALPHA-TOCOPHEROL [J].
CILLARD, J ;
CILLARD, P ;
CORMIER, M .
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY, 1980, 57 (08) :255-261
[4]   VOLATILE LIPID OXIDATION-PRODUCTS [J].
FRANKEL, EN .
PROGRESS IN LIPID RESEARCH, 1983, 22 (01) :1-33
[5]   INTERFACIAL PHENOMENA IN THE EVALUATION OF ANTIOXIDANTS - BULK OILS VS EMULSIONS [J].
FRANKEL, EN ;
HUANG, SW ;
KANNER, J ;
GERMAN, JB .
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 1994, 42 (05) :1054-1059
[6]   MODEL STUDY OF DIFFERENT ANTIOXIDANT PROPERTIES OF ALPHA-TOCOPHEROL AND GAMMA-TOCOPHEROL IN FATS [J].
GOTTSTEIN, T ;
GROSCH, W .
FETT WISSENSCHAFT TECHNOLOGIE-FAT SCIENCE TECHNOLOGY, 1990, 92 (04) :139-144
[7]   KINETIC EVALUATION OF LIPOPHILIC INHIBITORS OF LIPID-PEROXIDATION IN DLPC LIPOSOMES [J].
HORAN, KL ;
LUTZKE, BS ;
CAZERS, AR ;
MCCALL, JM ;
EPPS, DE .
FREE RADICAL BIOLOGY AND MEDICINE, 1994, 17 (06) :587-596
[8]   EFFECTS OF INDIVIDUAL TOCOPHEROLS AND TOCOPHEROL MIXTURES ON THE OXIDATIVE STABILITY OF CORN-OIL TRIGLYCERIDES [J].
HUANG, SW ;
FRANKEL, EN ;
GERMAN, JB .
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 1995, 43 (09) :2345-2350
[9]   Antioxidant activity of alpha-tocopherol and Trolox in different lipid substrates: Bulk oils vs oil-in-water emulsions [J].
Huang, SW ;
Hopia, A ;
Schwarz, K ;
Frankel, EN ;
German, JB .
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 1996, 44 (02) :444-452
[10]  
LOURY M, 1966, REV FRANC CORPS GRAS, V13, P747