Drying Conditions and Processability of Dried Rapeseed

The possibility of using the oil-point and compression tests for evaluation of dried rapeseeds processability was examined. Seeds of initial moisture 10, 14, 18 and 22% (w/w) were dried at 60, 80, 100 and 120°C to a final moisture of 6·5% (w/w). The values of pressure ( P ₀ ), work ( L ₀ ) and strain (ε₀) determined by the oil-point test, and pressure at strain ε=0·45 mm mm⁻¹ ( P_ε ) and degree of elasticity ( D ) determined by the compression test for bulk dried seeds differed markedly from those found for non-dried seeds. The P ₀ , L ₀ and P_ε values were strongly correlated with the initial moisture of rapeseeds and drying temperature. All the strain values (ε₀) were lower than those for non-dried seeds, and their changes depended solely on the initial moisture of seeds. Changes in the degree of elasticity were irregular and did not reach the value characteristic for overdried seeds, ie 100%. High correlation of the agglomeration test data (Δ_1–3 values) with those of the P ₀ , L ₀ and P_ε made it possible to develop appropriate equations that proved the usefulness of the variables for determining the dried rapeseed processability.