Seeds were milled using a domestic blender. Flour was suspended
in water and taken to pH 4.3 with 1 N HCl for extraction
under continuous stirring for 1 h. Extracts were centrifuged at
15,000g for 20 min, and pellets were extracted two more times
as described above. The three resulting supernatants were pooled
and used for the purification of arginine.