Influence of hammer mill screen size on processing parameters and starch enrichment in milled sorghum

Abstract

The effect of hammer mill screen size on processing parameters and particle size of milled sorghum were examined. Sorghum grains were ground through two levels of hammer mill screen size: 2 mm and 6 mm and then subsequently fractionated by size on a set of eight sieves ranging from 0.045 mm to 2.8 mm. The objective of this experiment were: i) to characterize the influence of hammer mill screen size (2 and 6 mm) on processing parameters: production output, energy consumption, average particle size (dgw), geometric standard deviation (sgw); ii) to characterize the influence of particle size, after segregation by sieving, on starch enrichment. The results of this study showed that using 6 mm hammer milling screen size has resulted in a significant effect on production output, energy consumption, dgw with no effect on sgw. Different particle sizes, when segregated by sieving, have shown significant effect on starch content. Particle size retained by sieve size 1.7 mm had the highest starch content, whereas particles retained by sieve size 0.125 mm had the lowest, which suggest potential applications in ruminant and monogastric nutrition.