FRACTIONATION AND CHARACTERIZATION OF A PROTEIN-FRACTION PRODUCING OFF-FLAVOR VOLATILES IN PEANUT SEED

A high molecular weight protein fraction (peak I) obtained from peanut (Arachis hypogaea L. cv. Florunner) seed was fractionated using ammon ium sulfate and methanol to isolate the protein(s) involved in off-fla vor volatile production during roasting of peanut. The results showed that maximum off-flavor volatile-producing activity is associated with the 20% ammonium sulfate precipitate and 85% methanol-soluble fractio n of this protein. Peak I protein was found to be lipoprotein in natur e and is rich in oleic acid (63%) and palmetic acid (8%). Furthermore, the 85% methanol-soluble fraction of peak I protein was found to cont ain a mixture of low molecular weight proteins and major amounts of gl ycine (11%), alanine (11%), proline (15%), phenylalanine (8%), and lys ine (8%).