Effect of Traditional Processing Methods on the Nutritional Composition of Sorghum (Sorghum bicolour L. Moench) Flour

Abstract

Sorghum is a drought-resistant crop grown widely in various parts of India. It has low protein content, highly deficient in essential amino acids lysine and tryptophan and high anti-nutritional content. Therefore, keeping in view the present study aimed to determine the effect of traditional processing methods such as fermentation, malting and roasting on the proximate composition, anti-nutritional factors, protein digestibility and lysine content of sorghum. The results showed that ash content increased from 1.73 to 1.89% during roasting. Fermentation increased crude protein content from 8.27 to 8.98% and in vitro protein digestibility from 13.62 to 69.63%. Malting decreased the crude fat content from 1.87 to 1.22% while it shows a significant increase in crude fiber content from 3.34 to 4.26% and carbohydrate content from 84.77 to 86.15%. Total phenol content reduced from 92.62 to 48.40 mg GAE/100 g, and tannin content reduced from 8.46 to 1.25 mg TAE/100 g during fermentation. The lysine content increased significantly during fermentation (1.88 g/16 g of N) and malting (1.94 g/16 g of N). Natural fermentation of sorghum flour found to have improved nutritional quality than other processing methods.