Pulse cleaning is the mechanical removal of dust, soil, stones, straw, weed seeds and damaged seeds from dry pulses using sieves, aspirators and destoners, and is essential for food safety and protecting downstream processing equipment.
In trade practice
Processing facilities run pulses through a sequence of sieve decks, air aspirators and destoners before dehulling, splitting or packing. QA teams check cleaning efficiency by measuring residual impurity levels against contract tolerances, typically expressed as a percentage by weight. A common mistake is skipping a cleaning pass when throughput is high, which allows stones or weed seeds to reach the colour sorter or packing line. Certificates of analysis issued by the exporter or an independent laboratory should confirm impurity levels.
In a specification
A purchase specification should state maximum permitted levels for each impurity category, such as stones, weed seeds and damaged kernels, expressed as a percentage by weight, and reference the sampling method used to verify them.