The solubility of wheat gluten was greatly improved at pH 4 or lower where it showed good emulsifying activity. This might be due to its high surface activity in the acidic pH range and the formation of a stable protein film surrounding the oil droplets. Among the major gluten proteins, gliadins showed higher surface activity than glutenins, The content of glutenins in the adsorbed protein film was higher than that of gliadins, and glutenins are likely to have been adsorbed more tightly than gliadins. These results suggest that gluten proteins exhibit complex behavior, such as adsorption/desorption/displacement/rearrangement during the adsorption process in a gluten-stabilized emulsion.