Effect of extrusion processing and simulated human digestion on the allergenicity of bambara groundnut protein

Abstract

SummaryExtrusion has been reported as a method for reducing protein allergenicity. This study aimed to investigate the effect of extrusion on proteins contained in bambara groundnut flour on the allergenicity of the nut. Allergenicity could also be assessed after human digestion using simulated enzyme digestion. Bambara groundnut flour was extruded and followed by pepsin and pancreatin digestion. SDS‐PAGE, immunoblotting and ELISA were performed to reveal the protein profiles before and after extrusion and to locate the proteins with their IgE binding properties. Two bands following SDS‐PAGE at a similar range of molecular weight (11 and 13 kDa) were identified with the IgE binding in 4 of 10 human sera after the raw bambara groundnut flour was digested by the digestion enzymes. On the contrary, none of the protein bands was observed in its extruded flour, with or without simulated digestion treatment. ELISA analysis showed that the extrusion could decrease allergenicity by approximately 60%. After digestion, the allergenicity reduction of the extruded flour could reach 100%. Therefore, extrusion is a promising food processing method to reduce the allergenicity of bambara groundnut protein.