Activated Carbon and Ion Exchange Treatments for Removing Phenolics and Phytate from Peanut Protein Products

Commercial defatted peanut flour and laboratory defatted peanut meal contained 1.5 and 1.7% phytate, 1756 and 2033 μg g^?1 total phenolic acids and 50 and 120 μg g^?1 neutral phenolics, respectively. Laboratory peanut protein isolate contained undetectable amounts of neutral phenolics, 810 μg g^?1 total phenolic acids and about 1% phytate. The ion exchange treatment removed ≥85% of the phytate and the ion exchange and activated carbon treatments removed 92 and 82%, respectively, of the total phenolic acids from peanut protein isolate. p-Coumaric acid was the major phenolic acid, accounting for 40–68% of the total phenolic acids in all peanut protein products.