Improvement of energy and nutrient density of sorghum-based complementary foods using germination

In Ethiopia, commercially made complementary foods are not available and affordable for the majority of the poor. Complementary foods prepared traditionally from locally available raw materials (such as cereals) have high viscosity when reconstituted. This limits the total food intake by infants. The main objective of this study was to investigate the effect of germination on energy and nutrient density of sorghum-based complementary foods. Two varieties of sorghum (Sorghum bicolor) (L.) Moench) grains (varieties 76T1#23 and Meko) were collected, cleaned, soaked for 22 hours at room temperature (22±2 ⁰ C); germinated for 48 hours at the soaking temperature; dried at 55 ⁰ C for 24 hours, and milled into a fine homogeneous powder. Five complementary foods were formulated by using a blend of ungerminated to germinated sorghum flours in ratios of 100:0, 75:25, 50:50 and 25:75, 0:100, respectively. Germination increased significantly (p<0.05) contents of crude protein from 12.25% and 10.44% to 12.65% and 10.87% for varieties 76T1#23 and Meko, respectively. Similarly, the respective contents of total phosphorus, iron, zinc and calcium (mg/100g) were significantly (p<0.05) increased from 208.42, 8.21, 1.86 and 17.09 to 223.26, 11.99, 2.01 and 25.93 for variety 76T1#23 and from 183.04 , 7.19 , 1.78 and 20.99 to 192.91, 10.98 , 1.89 and 29.62 for variety Meko. In contrast, germination decreased viscosity values (cP) (at five percent dry matter concentrations) from 2888.78 and 2988.43 to 1147.11 and 1148.20 for varieties 76T1#23 and Meko, respectively and at 15% dry matter concentrations from 8684.74 and 8791.98 to 2376.17 and 2416.24 for variety 76T1#23 and Meko, respectively. Blending of ungerminated with germinated sorghum flour also decreased viscosity values significantly. Panelists preferred gruels prepared from 100% ungerminated sorghum flour followed by gruels prepared from a blend of 75% ungerminated and 25% germinated sorghum flours. Gruels prepared from 100% germinated sorghum flour were least preferred. Hence, germination appeared to be a promising food processing method to improve energy and nutrient density and decrease viscosity values of complementary foods.