The effects of phytic acid on the physical and oxidative stability of flaxseed oil-in-water emulsions containing whey protein-coated lipid droplets were investigated. The surface potential, particle size, microstructure, appearance, and oxidation of these emulsions were monitored when they were stored at pH 3.5 and 7.0 for 25 days in the dark (37 °C). The phytic acid and protein-coated lipid droplets had similar charges (both negative) at pH 7.0, but had opposite charges (negative and positive) at pH 3.5. At pH 7.0, the addition of phytic acid had no impact on the physical stability of the emulsions but significantly improved their oxidative stability, which was attributed to its ability to sequester pro-oxidant transition metals (iron ions). At pH 3.5, extensive droplet aggregation and creaming occurred in the emulsions containing phytic acid, which was ascribed to charge neutralization and ion bridging. The oxidative stability of the acidified emulsions, however, still increased after addition of phytic acid, which was again attributed to its ability to chelate iron ions. Interestingly, the antioxidant activity of phytic acid decreased as its level was increased. Our results suggest that phytic acid may be used as a natural antioxidant to improve the oxidative stability of food emulsions containing polyunsaturated fatty acids, but its level must be carefully controlled.

研究了植酸对含乳清蛋白包衣脂质滴的亚麻籽水包油乳液的物理和氧化稳定性的影响。当这些乳剂在黑暗（37°C）下在pH 3.5和7.0下保存25天时，监测其表面电势，粒度，微观结构，外观和氧化。植酸和蛋白包被的脂质滴在pH 7.0时具有相似的电荷（均为负），但在pH 3.5时具有相反的电荷（负和正）。在pH 7.0时，添加植酸对乳液的物理稳定性没有影响，但显着提高了其氧化稳定性，这归因于其螯合促氧化剂过渡金属（铁离子）的能力。在pH 3.5下，含有植酸的乳液中出现大量的液滴聚集和乳化现象，归因于电荷中和和离子桥联。然而，添加植酸后酸化乳液的氧化稳定性仍然提高，这再次归因于其螯合铁离子的能力。有趣的是，植酸的抗氧化活性随其含量的增加而降低。我们的结果表明，植酸可被用作天然抗氧化剂，以改善含有多不饱和脂肪酸的食品乳液的氧化稳定性，但必须小心控制其含量。植酸的抗氧化活性随其含量的增加而降低。我们的结果表明，植酸可以用作天然抗氧化剂，以提高含有多不饱和脂肪酸的食品乳液的氧化稳定性，但必须小心控制其含量。植酸的抗氧化活性随其含量的增加而降低。我们的结果表明，植酸可被用作天然抗氧化剂，以改善含有多不饱和脂肪酸的食品乳液的氧化稳定性，但必须小心控制其含量。