Embodiments of the present invention provide processes for extracting amino acids from mixtures of amino acids, and compositions and mixtures formed therefrom. Applications include separating and/or isolating non-aromatic amino acids, and/or separating aromatic amino acids into at least one fraction containing phenylalanine and tryrosine and a fraction containing L-.beta.-3-indolylalanine (L-.beta.-3) and providing natural or other amino acid mixtures thereof. The source of amino acids may include a natural source, such as an enzymatically hydrolyzed protein or other natural protein hydrolysates containing mixtures of free amino acids. The processes of embodiments of the present invention include contacting the mixture of amino acids with a resin or hydrophobic substance that is attractive to aromatic amino acids but not attractive to aliphatic amino acids to separate the aromatic amino acids from the rest of the mixture.