Each type of individual wild green sample consisted of about 50 individual sub-samples taken at various locations. These sub-samples were mixed in equal portions to give the composite sample that was analysed. For the preparation of the analytical samples the greens were thoroughly washed with plenty of water in order to remove any soil or dirt, discarded of inedible parts and finely chopped, exactly as they were treated for the recipe preparation. Then the raw greens were
homogenised by a common household vegetable blender, pre-frozen at 30 C and freeze dried.