Jacobsen C, Timm M, Meyer A S
Department of Seafood Research, Danish Institute for Fisheries Research, Technical University of Denmark, DK-2800 Lyngby, Denmark.
J Agric Food Chem. 2001 Aug;49(8):3947-56. doi: 10.1021/jf001253e.
The effect of ascorbic acid (0-4000 ppm) and pH (3.8-6.2) on oxidation and levels of iron and copper in various fractions of mayonnaise enriched with 16% fish oil was investigated. Ascorbic acid induced release of iron from the assumed oil-water interface into the aqueous phase at all pH levels, but this effect of ascorbic acid was strongest at low pH (pH 3.8-4.2). Ascorbic acid generally promoted formation of volatile oxidation compounds and reduced the peroxide value in mayonnaises. Peroxide values and total volatiles generally increased with decreasing pH values, suggesting that low pH promoted oxidation. It is proposed that iron bridges between the egg yolk proteins low-density lipoproteins, lipovitellin, and phosvitin at the oil-water interface are broken at low pH values, whereby iron ions become accessible as oxidation initiators. In the presence of ascorbic acid, oxidation is further enhanced due to the reduction of Fe(3+) to Fe(2+) that rapidly catalyzes lipid oxidation via lipid hydroperoxide decomposition at the oil-water interface in mayonnaise.
研究了抗坏血酸（0 - 4000 ppm）和pH值（3.8 - 6.2）对富含16%鱼油的蛋黄酱各组分中氧化以及铁和铜含量的影响。在所有pH值水平下，抗坏血酸都会促使铁从假定的油水界面释放到水相中，但抗坏血酸的这种作用在低pH值（pH 3.8 - 4.2）时最强。抗坏血酸通常会促进蛋黄酱中挥发性氧化化合物的形成并降低其过氧化值。过氧化值和总挥发物通常会随着pH值的降低而增加，这表明低pH值会促进氧化。有人提出，在低pH值下，油水界面处蛋黄蛋白低密度脂蛋白、卵黄磷蛋白和卵黄高磷蛋白之间的铁桥会断裂，从而使铁离子可作为氧化引发剂。在抗坏血酸存在的情况下，由于Fe(3+)还原为Fe(2+)，氧化会进一步增强，Fe(2+)会通过蛋黄酱油水界面处脂质过氧化氢的分解迅速催化脂质氧化。
