Pulse destoning is the mechanical separation of stones and other dense impurities from dry pulses using gravity tables or destoning machines, and is a critical food-safety step because stones can cause tooth injury and damage milling machinery.
In trade practice
Gravity destoners work by fluidising the pulse bed on a vibrating, inclined deck so that heavier particles migrate upward and are discharged separately. Operators calibrate air flow and deck angle for each pulse type and seed size, since incorrect settings allow small stones to pass through with the product. QA teams verify destoner performance by inspecting the reject stream and by periodic sieve checks on the cleaned product. Buyers may request a statement in the certificate of conformity confirming that destoning was performed.
In a specification
A contract or specification may require the supplier to confirm that a dedicated destoning step was included in the processing line and to declare the maximum stone content in the finished lot, expressed as a count or weight per unit.