Construction of Zein/Gum Arabic Complexes for Preparation of Fish Oil‐Based Emulsions: The Effect of <scp>pH</scp> and Storage Time

ABSTRACT This study investigated the effect of modified zein powder on the performance of fish oil (FO) emulsions. Powders were prepared using acetic acid and glycerol, then dissolved in sodium dodecyl sulfate solution. The final mixture was labeled MZ. The wall complex/material was constructed by adding MZ to gum arabic (GA) solution and dissolving FO in it to prepare an emulsion. The investigation was made as the impact of pH (3–8) and storage time (28 days). The results showed that pH significantly affected the protein solubility of the complex and the physical properties of both the complex and FO emulsion ( p &lt; 0.05). Stable complexes with smaller particle sizes (11–25 nm) were obtained at all pH values, with zeta potentials of −4 to −11 mV for GA ratios of 0.5, 1, and 1.5. Stable FO emulsions with small droplet sizes (1.3–2.0 μm), high zeta potentials (−6.44 to −8.26 mV), and low creaming indexes (CIs; 6%–25%) were obtained at pH 5 using these GA ratios. At this pH, the complex and emulsion remained physically stable for small particle sizes (&lt; 70 nm), droplet sizes (&lt; 3.30 μm), CI (&lt; 46%), and zeta potential was −5 mV after 28‐day storage using these GA ratios. Fluorescence microscopy confirmed the droplet size changes. At pH 5, an MZ/GA ratio of 1:1.5 resulted in the lowest oxidation rate while stabilizing the omega‐3 fatty acids in the FO emulsion. Therefore, MZ/GA is a useful wall component for protecting FO against physical and oxidative instabilities.