Lipid oxidation in oil-in-water emulsions: Iron complexation by buffer ions and transfer on the interface as a possible mechanism

Lipid oxidation is the main hurdle for omega-3 fatty acid enrichment in food and beverages. Fat reduces quality safety of supplemented products. A tuna oil-in-water emulsion (20% v/v) was exposed to iron-induced oxidation. Emulsions with changing emulsifiers buffers were analyzed under different storage conditions (argon purging, pH variation) using Conjugated Dienes Thiobarbituric reactive substances assays. The results showed that free iron ions cannot interact oxygen. However, (Citrate phosphate) chelate (Fe (II)). Depending on value type buffer-Fe (II) complex, its prooxidant activity spatial distribution are influenced. complex charge defines interactions oil-water interface, i.e., positively charged interfaces repel complexes which keeps away. mechanistic understanding this work will help formulators product developers choose right buffer emulsifier combination sensitive emulsions.