We developed a new method for estimating antioxidant (AO) distributions in emulsions based on pseudophase models for chemical reactivity in micelles and microemulsions. AO distributions are expressed in terms of two partition constants between oil-interface (P_O^I) and water-interface (P_W^I) regions within the emulsions. To estimate values of P_O^I and P_W^I requires two independent data sets described by mathematical relations (models) that are dependent on these parameters and solving two equations in two unknowns. One data set is obtained from the observed rate constant (k_obs) measured electrochemically for reaction of the AO with an arenediazonium ion with increasing nonionic surfactant in a stirred tributyrin-water emulsion. The other data set is obtained by measuring the distribution constant of the AO between tributyrin and water in the absence of emulsifier by UV-Visible spectrometry. The distribution of t-butyl hydroquinone (TBHQ) was determined in a simple model food emulsion - hexaethyleneglycol monododecyl ether (C₁₂E₆)/water/tributyrin at 25 °C. From the P_O^I and P_W^I values, we estimate that about 65% of TBHQ is located in the interfacial region at about 2% of C₁₂E₆ with significant percentage of TBHQ in the tributyrin region. The distribution constant (K) of TBHQ between water and tributyrin in the absence of C₁₂E₆ is 0.015.