Gums and proteins are valuable ingredients with a wide spectrum of applications. Surface properties (surface tension, interfacial tension, emulsion activity index "EAI". and emulsion stability index "ESI") of 4% whey protein concentrate (WPC) in a combination with iota-carrageenan (0.05%, 0.1%, and 0.5%) or gum arabic (0.5%, 1%, and 5%) were investigated. The results showed that the addition of i-carrageenan to 4% WPC significantly decreased interfacial tension, and improved the EAI, and ESI, but addition of gum arabic to 4% WPC significantly increased the interfacial tension. EAI, and ESI. In addition, a fuzzy-based clustering model was used to predict the surface properties. The fuzzy model achieved accuracies of (94%, 97%, 98%, and 94%) for predicting (EAI, ESI, surface tension, and interfacial tension), respectively. (C) 2008 Elsevier Ltd. All rights reserved.