Anti-Nutrients Composition of Starch Isolated from Red and White Sorghum Cultivars Subjected to Different Steeping Time

Abstract

Sorghum is a food crop that serves as a major source of calories to a substantial number of populations living in semi-arid tropics of Africa, Asia and other countries of the world. Steeping processing techniques improves nutritional qualities, palatability and consumer acceptability of foods crops. The effects of steeping periods on the anti-nutrient composition of starch isolated from two varieties of sorghum (red and white) were investigated. Sorghum steeped for period of 6, 12, 18 and 24 h with water were processed into starch and sample from unsteeped sorghum was used as control. The starch samples were analysed for anti-nutrients components using standard analytical procedure. Anti-nutrients investigated varied with cultivars and increased steeping time. Hydrogen cyanide observed was in the range of 1.34 to 1.86 mg/kg, tannin 1.30 to 4.82 mg/g, saponin 6.10 to 13.05 mg/g, oxalate 0.43 to 0.90 mg/g, phytate 2.15 to 9.06 mg/g, cardiac glycoside 9.30 to 13.35 mg/g, terpenoid 13.50 to 18.99 mg/g and alkaloid 3.41mg/g to 5.03 mg/g. The objective of the research is to determine the anti-nutrients composition of starch isolated from red and white sorghum. Significant difference was not observed between starch from the two cultivars of sorghum in most of the parameters investigated. However, the red cultivar recorded higher values in some of the anti-nutrients investigated. The anti-nutrient levels significantly reduce with increase in steeping time thus improving bioavailability of mineral element and other nutrients found in sorghum. The mixture of two varieties (red and white) could find applications in food formulations.