Ascorbic acid and ascorbic acid 6-palmitate induced oxidation in egg yolk dispersions

The oxidation in aqueous dispersions of egg yolk powder and the influence o f addition of the proposed antioxidants ascorbic acid and ascorbic acid 6-p almitate indicate that both ascorbic acid and ascorbic acid 6-palmitate pro pagated the oxidation of egg yolk powder dispersions. Ascorbic acid 6-palmi tate was found to be more prooxidative than ascorbic acid. Moreover, it was found that addition of ascorbic acid or ascorbic acid 6-palmitate gave ris e to an increase in the amount of free iron Fe(II) in the egg yolk dispersi ons. It is proposed that ascorbic acid and ascorbic acid 6-palmitate react with the phosvitin-Fe(III) complex found in egg yolk and release Fe(II), wh ich subsequently propagates lipid oxidation. It appears that less oxidation occurs in egg yolk dispersions exposed to high concentrations of peroxy ra dicals with added ascorbic acid than egg yolk dispersions with added ascorb ic acid without exposure to peroxy radicals.