The rasper disintegrates the roots into a suspension of free starch granules, fibers, bounded starch and fruit water containing solubles such protein, sugars and minerals. During rasping processwater is added for dilution. As the rasping efficiency (the percentage free starch gained) is crucial for the yield of the process,the rasper is designed to achieve the highest possible rasping efficiency. During the period of saw blade changing: one rasper is stopped, the other rasper runs at full capacity. The small capacity drop is buffered by the big crude starch milk tank.