ENZYME-AIDED VS 2-STAGE PROCESSING OF CANOLA - TECHNOLOGY, PRODUCT QUALITY AND COST EVALUATION

The investigation focussed on the use of carbohydrase enzymes to enhance oil extraction during pressing in a laboratory expeller. Enzyme-treated seeds at 6% moisture were pressed in the expeller set at full-press conditions. Control seeds were pressed at wider choke openings but at the same barrel pressures as enzyme-treated samples. Time of pressing and temperature and pressure inside the expeller barrel were used to calculate throughput and energy requirements per unit weight of processed material. Treatment with enzymes improved throughput of the expeller, increased oil flow rate and oil recovery. Material throughput was increased by 30-50%, depending on canola variety. The recovery of the oil was increased from 72% of the seed oil for control samples, to 90-93% for enzyme-treated samples. The average residual oil content in presscakes from enzyme-treated seeds was 7.4% The oil quality was inferior to cold-pressed control but was much better than has been reported for solvent-extracted oil.