Dependence of flour yield on moisture content of chickpea seeds

Introduction.The aim of the study was to determine the effect of chickpea seed moisture on the yield of flour (sieve mesh size 132 µm) obtained in hammer and roller mills.Materials and methods.Primary crushing of chickpea seeds was performed in a hammer mill with a sieve hole diameter of 4 mm and a hammer rotation speed of 80 m/s.Chickpea seeds were crushed in a roller mill using corrugated and smooth rollers with three crushing and grinding systems.After each system, the flour was separated and the flour yield was determined in relation to the initial weight of the seeds.Results and discussion.Grinding dry chickpea seeds with 8.9% moisture content in a hammer mill yielded 10.5% flour.Increasing the chickpea moisture content to 11.6% increased the flour yield to 11.9%.Further increasing the chickpea moisture content decreased the flour yield (132 µm sieve pass).The optimum moisture content was 11.5%.The highest flour yield was 12.0% with a moisture content of 11.5%.The total flour yield from chickpea seeds crushed in a roller mill was only 50.6% (sieve pass 132 µm).The flour yield on 2-and 3-crushing systems was only 1.0% and 1.2%, respectively.This means that these break systems with corrugated rollers are not practical to use due to the low flour yield.To obtain a higher yield of chickpea flour, it is necessary to increase the number of milling systems.It was not possible to completely grind the chickpea kernel and achieve the maximum possible flour yield from the kernel due to the insufficient length of the roller installation line (3-crushing systems).Analysis of the cumulative flour whiteness curve shows that with increasing flour yield, its whiteness decreases from 39.8 to 27.0 units.It indicates that the flour quality decreases with increasing flour yield. Conclusion.For intermediate crushing of chickpea seeds with subsequent crushing on smooth rollers, one crushing system is sufficient.For more complete crushing of chickpea seeds, it is necessary to increase the number of crushing systems.