A process for the treatment of leafy green plants such as lucerne (alfalfa) for the extraction of proteins in the pressing juices and an economical dehydration of cake, yield: (1) High level of juice extraction by pressing the raw material plant, resulting in a simultaneous and marked lowering in the moisture content thereof; (2) An improvement of the overall heat balance, in relation with the saving of heat obtained, during dehydration of the pressed vegetable matter cake, and during concentration of the serum by concentration in a multiple effect apparatus, (3) Maximum recovery of the proteins present in the pressing juice, with the production of a dehydrated protein concentrate usable in human nutrition and animal feeding. The specification discloses a process involving: (a) preliminary treatment of vegetable matter,(b) pressing the matter obtained in said step (2), thus providing a cake and a brown colored pressing juice, (c) dehydration of the cake obtained in step (b), the improvement being that s
