Isolation and Characterization of a Peanut Maturity-Associated Protein

Using reversed-phase high-performance liquid chromatography (RP-HPLC), the peanut protein profile was shown to be related to the maturity, drying time, and drying procedure of the peanut. Differences were seen between (a) immature and mature seeds for untreated and windrow-dried peanuts, (b) untreated and windrow-dried peanuts for immature and mature seeds, and (c) windrow- and stackpole-dried peanuts. The most pronounced HPLC peak that increased in size as the peanut matured and decreased in size with longer drying times was isolated and identified by sodium dodecyl sulfate−polyacrylamide gel electrophoresis and electrospray ionization mass spectrometry to have a molecular weight of 62 500. Since maturity is related to the sensory quality of peanuts, this protein may be a marker for peanuts that will produce a higher quality flavor when roasted. Keywords: Peanut; Arachis hypogaia L.; maturity; reversed-phase high-performance liquid chromatography; isolation; electrospray mass spectrometry