Technical Abstract: Pistachio (Pistacia vera) is a tree nut that has been reported to cause IgE-mediated allergic reactions. This study was undertaken to investigate the distinction between different cultivars of pistachio nut, and the influence of different processing on the IgE-binding capacity of whole pistachio protein extracts. The influence of different processes on allergenicity was investigated using competitive inhibition ELISA and Western blotting assays. The Western blotting results of extracts from pistachio cultivars showed no marked difference among them. The IgE-binding capacity was significantly lower for the protein extract prepared from steam-roasted, than from raw and dry-roasted pistachio nuts. The results of sensory evaluation analysis and hedonic rating proved no significant differences in taste quality between raw, roasted, and steam-roasted pistachio nut treatments. The most significant finding of the present study was the successful reduction of IgE binding by pistachio extracts using steam-roast processing without any significant changes in sensory quality of product.