EFFECT OF FERMENTATION ON BIOCHEMICAL CHARACTERISTICS OF SORGHUM FLOUR SUPPLEMENTED WITH CHICKPEA FLOUR

Sorghum flour was supplemented with 15 and 30% chickpea flour. Sorghum flour and the supplement were fermented at 35 oC for 0, 8, 16, and 24 h. Changes in pH, titrable acidity, total soluble solids, protein content, in vitro protein digestibility and amino acid composition were investigated during fermentation and/or after supplementation. The pH of the fermented materials decreased sharply with a concomitant increase in the titrable acidity. The total soluble solids remained unchanged with progressive fermentation time. The protein content of sorghum was found to be 9.27 and that of chickpea was 22.47%. The protein content of sorghum cultivar after supplementation with15 and 30% chickpea was significantly (P < 0.05) increased to 11.78 and 14.55%, respectively. The protein digestibility was increased after fermentation from 13.35 to 30.59 and 40.56% for the supplements, respectively. Further increment in protein content and digestibility was observed when supplemented samples were fermented for different periods of time. Cooking of fermented samples was found to increase the protein content slightly but decreased its digestibility for both supplements. Supplementation was found to increase the lysine and therionine content. However, cooking following fermentation decreased lysine, isoleucine, valine and sulfur containg amino acids.