Changes in sorghum enzyme inhibitors, phytic acid, tannins and in vitro protein digestibility occurring during Khamir (local bread) fermentation

Abstract

Effects of traditional fermentation on enzyme inhibitors, phytic acid, tannin content and in vitro digestibility of three local sorghum varieties were investigated. During a 24 h fermentation, enzyme inhibitory activities were significantly decreased. Trypsin inhibitory activity was reduced by 58%, 43% and 31% in Hamra, Shahla and Baidha, respectively, whereas amylase inhibitory activity was reduced by 74, 75 and in the three varieties after a 24 h fermentation. Phytic acid contents of the three varieties were markedly reduced as a result of fermentation. Tannin content of Hamra, Shahla and Baidha were significantly reduced by, respectively, 31%, 15% and 35% after fermentation. Fermentation significantly improved the in vitro digestibility of sorghum proteins.