An impeller adapted to be coaxially mounted within an annular-shaped cutting head for rotation about a rotational axis thereof in a rotational direction relative to the cutting head, the impeller comprising: a base and a ring spaced axially from each other, and a flange that extends in a generally axial direction from the ring to define an entrance to the impeller through which products enter the impeller; characterized by one or more intermediate plates (60A, 60B) disposed between the base and the ring and comprising at least a first intermediate plate so as to define at least first and second tier levels (70A,70B) within the impeller, the first tier level being an upper tier level within the impeller and the second tier level being a lower tier level within the impeller, the first tier level being between the ring and the first intermediate plate, the second tier level being between the first intermediate plate and the base, the first intermediate plate having an annular shape that includes a substantially planar portion surrounding a frustoconical flange that extends in a generally axial direction from the planar portion, the flange defining an opening that is concentric with the rotational axis of the impeller and defines a passage between the first and second tier levels (70A,70B) through which products are able to pass to enter the second tier level such that the first intermediate plate functions as a baffle whereby a fraction of the products entering the impeller through the entrance is captured within the first tier level as a result of encountering and being deflected by the planar portion or the flange of the first intermediate plate and a second fraction of the products entering the impeller passes through the opening in the first intermediate plate and is captured within the second tier level beneath the opening of the first intermediate plate; paddles disposed between the base and the ring, at least a portion of each paddle being disposed within at least one of the first and second tier levels (70A,70B), each of the paddles having a radially outer extremity adjacent an outer perimeter of the impeller, an oppositely-disposed radially inner extremity, and a face between the radially inner and outer extremities and facing the rotational direction of the impeller, and pockets defined within each of the first and second tier levels (70A,70B), each pocket being disposed between a pair of the paddles that are immediately adjacent each other in the rotational direction of the impeller, the pockets being delimited in an axial direction of the impeller by the base, the ring, and at least the first intermediate plate. a base and a ring spaced axially from each other, and a flange that extends in a generally axial direction from the ring to define an entrance to the impeller through which products enter the impeller; characterized by one or more intermediate plates (60A, 60B) disposed between the base and the ring and comprising at least a first intermediate plate so as to define at least first and second tier levels (70A,70B) within the impeller, the first tier level being an upper tier level within the impeller and the second tier level being a lower tier level within the impeller, the first tier level being between the ring and the first intermediate plate, the second tier level being between the first intermediate plate and the base, the first intermediate plate having an annular shape that includes a substantially planar portion surrounding a frustoconical flange that extends in a generally axial direction from the planar portion, the flange defining an opening that is concentric with the rotational axis of the impeller and defines a passage between the first and second tier levels (70A,70B) through which products are able to pass to enter the second tier level such that the first intermediate plate functions as a baffle whereby a fraction of the products entering the impeller through the entrance is captured within the first tier level as a result of encountering and being deflected by the planar portion or the flange of the first intermediate plate and a second fraction of the products entering the impeller passes through the opening in the first intermediate plate and is captured within the second tier level beneath the opening of the first intermediate plate; paddles disposed between the base and the ring, at least a portion of each paddle being disposed within at least one of the first and second tier levels (70A,70B), each of the paddles having a radially outer extremity adjacent an outer perimeter of the impeller, an oppositely-disposed radially inner extremity, and a face between the radially inner and outer extremities and facing the rotational direction of the impeller, and pockets defined within each of the first and second tier levels (70A,70B), each pocket being disposed between a pair of the paddles that are immediately adjacent each other in the rotational direction of the impeller, the pockets being delimited in an axial direction of the impeller by the base, the ring, and at least the first intermediate plate.