Bj. Lee et Dg. Hendricks, METAL-CATALYZED OXIDATION OF ASCORBATE, DEOXYRIBOSE AND LINOLEIC-ACIDAS AFFECTED BY PHYTIC ACID IN A MODEL SYSTEM, Journal of food science, 62(5), 1997, pp. 935
Antioxidant activity of phytate was investigated in metal-catalyzed mo
del systems. In a dose-dependent manner, phytate facilitated oxidation
of Fe (II) to Fe (III) and inhibited formation of thiobarbituric acid
-reactive substances (TBARS) from Fe (II)- or hemeprotein-catalyzed de
oxyribose degradation. In the presence of 100 mu M Fe (III), phytate i
nhibited reduction of Fe (III) to Fe (II) by 100 mu M ascorbic acid an
d it consequently inhibited ascorbate oxidation. Phytate inhibited hem
eprotein- and H2O2-catalyzed TBARS formation from linoleic acid micell
es. Inhibition dy phytate of iron + ascorbate-dependent lipid peroxida
tion depended on the concentration of ascorbate. These results indicat
e that phytate may be a useful antioxidant in the protection against o
xidative deterioration of foods.