Oilseed cleaning is the mechanical removal of foreign matter, including dust, stones, weed seeds, stems and damaged kernels, from rapeseed, sunflower, soybean or linseed prior to conditioning and pressing, protecting processing equipment and improving the quality of both oil and meal.
In trade practice
Cleaning lines typically combine scalpers, aspirators, indent cylinders and destoners in sequence, with each machine targeting a different impurity type by size, density or aerodynamic properties. The cleaned seed is weighed and sampled, and the impurity level is recorded as a percentage of total mass; this figure feeds into the quality certificate issued at the crushing plant or export point. A common error is inadequate removal of weed seeds containing toxic alkaloids, which can contaminate meal and trigger rejection under EU feed safety rules. Buyers and crushers should request cleaning records and confirm that impurity levels in the delivered seed meet contracted tolerances.
In a specification
An oilseed purchase contract typically states a maximum admixture or impurity percentage by mass, with sub-limits for specific contaminants such as ergot bodies or seeds of harmful plants, and requires the seller to provide a quality certificate confirming compliance at point of loading.