Salts reduction/substitution have gained a lot interest from food industry since the US Food and Drug Administration (FDA) has issued a draft guidance for salt reduction. However how changes of salts in food formulation could influence lipid oxidation is still not fully understood. Using oil-in-water emulsions stabilized by a natural emulsifier – lecithin at pH 7.0 as a model system, this study evaluated how salts affect the physical parameters of the emulsion, the chelating activity of lecithin and thus the lipid oxidation of these emulsions. Results showed that salts increased the particle size, the negative charge of the oil droplets, and the amount of iron chelated by lecithin. Lipid oxidation lag phases were shortened by addition of salts, by 1 day and 2 days for lipid hydroperoxides and thiobarbituric acid reactive substances measurements respectively. These results provide some new insights on the mechanisms of how salts could affect the lipid oxidation of food emulsions.

自美国食品和药物管理局（FDA）发布减盐指南草案以来，减盐/替代盐在食品行业引起了广泛关注。然而，食品配方中盐的变化如何影响脂质氧化仍未完全了解。以天然乳化剂（pH 7.0的卵磷脂）稳定的水包油乳状液为模型系统，本研究评估了盐如何影响乳状液的物理参数，卵磷脂的螯合活性并进而影响这些乳状液的脂质氧化。结果表明，盐增加了粒径，油滴的负电荷以及卵磷脂螯合的铁量。加入盐可缩短脂质氧化滞后阶段，分别测量脂质氢过氧化物和硫代巴比妥酸反应性物质的1天和2天。这些结果为盐如何影响食品乳状液脂质氧化的机理提供了一些新见解。