PROTEIN CONTENT AND DIGESTIBILITY OF SORGHUM (SORGHUM BICOLOR)-BASED FERMENTED GRUEL: EFFECT OF SUPPLEMENTATION WITH SOYBEAN PROTEIN

Changes in pH, protein content and in vitro protein digestibility (IVPD) were investigated during fermentation and/or cooking of the supplemented sorghum flour with soybean flour. The pH of the fermented material decreased with progressive fermentation. Supplementation with soybean flour resulted in drop in pH during the fermentation period but increased at 14 h. Protein content of the unsupplemented sorghum significantly (P < 0.05) increased for 14 h dough. The protein content of the cooked sample is higher compared to uncooked counterparts. Supplementation of sorghum with soybean resulted in 2-folds increase in protein content at commencement of fermentation. The IVPD of unsupplemented dough was in the range of 16.6 - 21.8%.The IVPD increased from 16.6% for unsupplemented sorghum to 37.2% in supplemented dough. Cooking of supplemented doughs showed high level of IVPD compared to unsupplemented cooked sorghum flour indicating the feasibility of utilizing soybean as supplement to sorghum.