Abstract: Disclosed is a method for preparing a protein isolate displaying a purity higher than 80% from plant parts, the method including the following successive steps: a) washing the plant parts in acidic conditions, thereby obtaining acid washed plant parts; b) contacting the acid washed plant parts with an alkaline solution; and c) recovering the liquid fraction thereby obtaining a protein isolate displaying a purity higher than 80%. The method does not include any acidic precipitation step.

Abstract: The crop lifters include a pair of rotatable disks with rims that converge towards each other below and to the rear of their centers and that diverge from each other above and forward of their centers. As the disks are carried forward by a harvester, each pair of disks gather plant material, grasp the plant material, lift the plant material and then release the plant material above an elevating conveyor. The disks remain above the surface of the ground and are rotated by crop material as the harvester moves forward or are driven by motors. Flexible disks have rims that are forced to converge by slide bearings. Semi-ridged disks are mounted on axes that extend toward each other, upward, and forward from each disk center. A plurality of pairs of disks can be carried by one harvester. A knife severs plants from their roots forward of the conveyor.