Biochemical changes during traditional fermentation of saudi sorghum (Sorghum bicolor l.) cultivars flour into khamir (local gluten free bread)

Abstract

Effect of traditional fermentation on pH, titratable acidity, proteins, amino acids, and sugars contents of three local sorghum cultivars namely Hamra, Biadah and Shahla used in making khamir local bread were investigated. During 24 fermentations, the pH of fermented dough dropped sharply and this was coincided with increase in total acidity. Fermentation was found to cause no significant change in protein content of the cultivars. Amino acid analysis, revealed slight insignificant improvement in lysine, and leucine content but there was a slight decrease in valine, phenyl alanine and arginine content in fermented dough. Glucose, fructose and maltose content of the three sorghum cultivars increased considerably in the early stages of fermentation, followed by decrease towards the end of fermentation. Low amount of sucrose detected in the three cultivars and it was completely utilized after 8 hrs. of fermentation.