Sucrose in cane is contained as juice within thin-walled cells protected by the fibrous structure of the stalk. For easy and efficient extraction of the sucrose, whether by milling or diffusion, it is necessary that the cells are first ruptured to expose the sucrose within the cells.
With good cane preparation, milling performance improves because:
- The juice is made available for easy extraction;
- The cane density is increased and it is more homogenous, assisting feed and throughput;
- Lower mill feed/discharge ratios can be used, reducing mill power requirement. The power saved in the mills approximately offsets the power used by a heavy-duty shredder;
- Re-absorption is reduced through improved juice drainage; and
- Bagasse moisture is improved.
The degree of preparation is the single most important factor in diffuser extraction. It affects both the following mechanisms in the diffusion process:
- The lixiviation or washing out of sucrose can only occur from exposed, broken cells; and
- The diffusion of sucrose from high brix juice inside cells through unbroken cell walls will only occur where the outer wall of the cell is in direct contact with lower brix liquid.