Physicochemical and Functional Characteristics of Sorghum Flour as Affected by Variety and Particle Size Distribution

Abstract

Sorghum (Sorghum bicolor L. Moench) is a promising cereal for food diversification due to its nutritional value and adaptability to marginal lands. This study investigated the influence of particle size on the physicochemical and functional properties of sorghum flour from four varieties. A factorial randomized block design with three replications was applied to four varieties of sorghum (Bioguma, Pahat, Samurai-1, and Samurai-2) and two particle sizes (200 and 300 mesh). Both variety and particle size significantly influenced flour characteristics. Reducing particle size from 200 to 300 mesh increased moisture, carbohydrate, starch content, lightness (L*), water-holding capacity (WHC), water absorption capacity (WAC), swelling power, and solubility, while decreasing protein, fat, crude fiber, oil holding capacity (OHC), oil absorption capacity (OAC), and a* and b* values. Starch content increased from 66.32–71.48% to 73.42–79.39%, along with increase of WHC (from 1.21–1.28 to 1.31–1.51 g/g) and WAC (from 116.59–156.05% to 166.76–213.14%). Meanwhile, amylose content exhibited a genotype-dependent response. Based on its hydration properties, the 300 mesh flour fraction shows potential as a functional ingredient for gluten-analog development and gluten-free bakery applications.