Effect of soaking on the nutritive value of some commonly consumed Sudanese grains (sorghum, white bean and faba bean)

Abstract

The aim of this work is to study the nutritive value after soaking treatment, of three varieties of grains (sorghum, white bean and faba bean). About400 g of the sorghum, white beans and faba beans grains were divided into 4 equal parts of 100 g each, cleaned to remove all extraneous matter and freed from broken grains then soaked separately. The immersing periods for each part of the soaked grains was 3, 6, 12, and 24 h, respectively in distilled water with a ratio 1:4 w/v. At the end of soaking period, the soaked water was discarded. The grains were rinsed with distilled water and dried at room temperature at (25°C), milled and kept at (20°C) until analysis The results showed that soaking of sorghum samples increased moisture content from 7.96% in raw sorghum to 10.78% at 24 h. While soaking reduced crude protein content 9.64% in raw sorghum to 8.95% at 24h, fat content ranged from 3.21% to 2.87% at 24h, carbohydrate content ranged from 75.12% to 74.22% at 24h, crude fiber content ranged from 2.44% to 1.74% at 24h, and ash content ranged from 1.630% to 1.446%at 24h. Soaking of white bean samples increased moisture content from 7.18% in raw white bean to 13.31% at 24. But soaking reduced another contents such as crude protein from 24.11% to 21.13 % at 24h, fat 2.02% to 1.15% at 24h, carbohydrates 56.73 to 55.63%, fiber 6.43% to 5.30% at 24h, ash 3.990% to 3.4826%. Soaking of faba bean samples increased the moisture content in raw fababean from 6.45% to 11.80%24h. While soaking reduced crude protein content from 28.88% to 26.93%24h, fat content from 1.53% to 0.87% at 24h, carbohydrates content 51.79% to 50.48% at 24, fiber content 7.80% to 6.58at 24h, ash content 3.56% to 3.34% at 24 h. Minerals content (mg/100g) of soaked sorghum samples decreased as soaking time increased calcium 14.33 to 12.12 at 24h, iron 6.58 to 4.3524h, magnesium 137.00 to 111.0024h. White bean calcium 36.87 to 23.20 at 24h. And iron 5.78 to 1.16 at 24h, magnesium 480.00 to 347.00 at 24h. And faba bean calcium 26.48 to 8.90 at 24h, iron 1.92to 0.47 at 24h, magnesium 165.00 to 180.00at 24h. Anti-nutritional factor content (mg/100g) decreased as soaking time increased in sorghum polyphenol from 6.07 to 5.20 at 24 h, tannin from 2.92 to 0.93 at 24 h, white bean polyphenol from 7.89 to 5.31 at 24 h, tannin from IV 1.57 to 0.47at 24 h.And faba bean polyphenol from 8.49 to 6.71at 24 h, tannin from 1.16 to 0.65 at 24 h. Soaking of sorghum, white beans and faba beans seems to reduce protein, fat, carbohydrate, fiber and ash of beans and can increase the moisture content.Soaking of sorghum, white beans and faba beans also seems to reduce minerals content such as calcium, iron and magnesium.Soaking of sorghum, white beans and faba beans improved the nutritional value of the sorghum because it leads to reduce the antinutritional factors, soaking was the most effective way to reduce tannins and poly phenolic compound.