Proteomic characterization of peanut flour fermented by Rhizopus oryzae
Christopher P. Mattison,
Rebecca A. Dupre,
Kristen Clermont,
John G. Gibbons,
Jae-Hyuk Yu
Affiliations
Christopher P. Mattison
U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, FPSQ, New Orleans, LA, 70124, USA; Corresponding author.
Rebecca A. Dupre
U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, FPSQ, New Orleans, LA, 70124, USA; Oak Ridge Institute for Science and Education, U.S. Department of Energy, Oak Ridge, TN, 37831, USA
Kristen Clermont
U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, FPSQ, New Orleans, LA, 70124, USA; Oak Ridge Institute for Science and Education, U.S. Department of Energy, Oak Ridge, TN, 37831, USA; Department of Biology, La Salle University, Philadelphia, PA, 19141, USA
John G. Gibbons
Department of Food Science, College of Natural Sciences, University of Massachusetts, Amherst, MA, 01003, USA
Jae-Hyuk Yu
Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA
Fermentation alters the protein content and composition of foods. To characterize fungal catabolism of peanut proteins, defatted peanut flour was fermented by Rhizopus oryzae (R. oryzae) for up to 48 h and evaluated by SDS-PAGE, mass spectrometry, and antibody binding. A clear change in peanut protein migration was observed by SDS-PAGE after 16 h of fermentation. Mass spectrometric analysis indicated changes in allergen peptides and R. oryzae proteins. Several low molecular weight allergen fragments produced during fermentation were identified by mass spectrometry. Immunoassays using anti-peanut allergen antibodies demonstrated reduced allergen content as early as 16 h of fermentation. However, ELISA with peanut allergic IgE indicated only slightly reduced allergen binding even after 48 h. These results indicate that while R. oryzae fermentation efficiently metabolizes peanut allergens, significant IgE binding remains in lower molecular mass peptides, and therefore R. oryzae fermented peanut products would not be safe for peanut allergic individuals.
