A centrifuge (10) is provided for recovering material of interest from the interstitial fluids of plant tissues. The centrifuge (10) includes a rotatable centrifuge bowl (12) having a radially outer wall (16) inclined outwardly so that during centrifugation liquid in the bowl (12) climbs the outer wall (16). The centrifuge bowl (12) is contained in a vacuum sealed housing (14) so that a material of interest contained in the bowl (12) including said liquid can be subjected to a vacuum. A system for automated cleaning of the centrifuge (10) is also provided.