Technical Abstract: Transglutaminase promotes protein crosslinking reactions through an acyl transferase mechanism involving protein-bound glutaminyl residues and primary amines including the '-amino group of lysine residues in soy, myosin, gluten, oat globulin, casein and whey. Herein, we present a first report of transglutaminase catalysis of several peanut protein fractions, including purified Ara h 1. In most cases, SDS-PAGE banding patterns revealed the formation of high molecular weight polymers while catalysis of Ara h 1 resulted in distinct dimer formation. Crosslinking effects were accomplished in the presence and absence of the reducing reagent, dithiothreitol. Ortho-phthaldialdehyde assays, used to quantify the degree of polymerization, indicated ~30% coupling using either cold hexane extracted peanut protein fractions or lightly roasted flour dispersions. Rheological measurements established that transglutaminase-modified peanut extracts exhibited lowered viscosity readings compared to non-treated dispersions. Peanut protein polymers and glycoprotein conjugates, created by covalent linkage between protein substrates and monosaccharide amino sugars, exhibited equivalent IgE binding activity, compared to control solutions. These results suggested that potential allergic responses were not enhanced after enzymatic modification. Ultimately, these approaches may provide novel peanut-based food ingredients with unique functional characteristics for expanded applications within the world marketplace.