Effects of twin-screw extrusion of peanut flour on in vitro digestion of potentially allergenic peanut proteins.
Partially defatted peanut flour was processed in a twin-screw extruder. Resulting extrudates were dried, ground, and incubated with simulated gastric fluid for various time periods. Soluble protein content of the resulting digesta was measured after 10% trichloroacetic acid treatment to evaluate the digestibility. In vitro digestion using pepsin increased the solubility of peanut protein in 10% trichloroacetic acid solution from 2 to 6% to 65 to 75%. Four strong IgE-binding subunits (65, 22, 17, and 14 kDa) were found with immunoblotting in peanut proteins extracted from unextruded peanut flour; no IgE-binding bands were observed in extrudates. The 65-kDa (putative Ara h 1) subunit was insolubilized during extrusion, and its IgE-binding property was susceptible to in vitro digestion. Following extrusion cooking, no IgE-binding bands were detected by immunoblotting, including the strongly IgE-binding 14-kDa fraction, a strong IgE-binding band from native peanut protein that is stable in pepsin. The 22- and 17-kDa (putative Ara h 2) subunits retained a small amount of IgE-binding potential and became susceptible to pepsin hydrolysis after extrusion.
Department of Food Science and Technology, University of Georgia, Griffin, Georgia 30223, USA.
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Phillips
D000485:Allergens / Q000276:immunology / Q000378:metabolism; D010367:Arachis / Q000276:immunology / Q000378:metabolism; D003257:Consumer Product Safety; D004063:Digestion; D005433:Flour; D005511:Food Handling / Q000379:methods*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D021183:Peanut Hypersensitivity / Q000517:prevention & control; D010434:Pepsin A / Q000378:metabolism; D010940:Plant Proteins / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D012995:Solubility
D000485:Allergens; D010940:Plant Proteins; D007073:Immunoglobulin E; D010434:Pepsin A