A very low cost extruder system was tested for the inactivation of phytohemagglutinins in beans, such as but not limited to cranberry beans. Cranberry beans were extruded at either 105 or 130.degree. C. (die end). The screw speed was 118, 194 or 255 revolutions per minute (rpm). The feed rate was set at either 85 or 120 g/min and moisture content was set at either 25 or 35%. The phytohemagglutinin activity in the extruded samples was determined in triplicate by Enzyme-Linked Immunosorbent Assay (ELISA). The very low cost extruder system inactivated active phytohemagglutinins in the extruded cranberry beans by over 98%.