CHANGES IN TANNIN AND CYANIDE CONTENTS AND DIASTIC ACTIVITY DURING GERMINATION AND THE EFFECT OF TRADITIONAL PROCESSING ON CYANIDE CONTENT OF SORGHUM CULTIVARS

Investigation of three sorghum cultivars showed that tannin content of ungerminated seeds were 220, 410 and 400 mg/100 g for Waznashra, Fete rita and Gadamelhamam cultivars, respectively. For all cultivars, unge rminated seeds were found to contain no free or total cyanide. Their d iastatic activities (the combined alpha- and beta-amylase activities) mere found to be zero. For all cultivars, tannin content was slightly increased when seeds were germinated for different periods. Both free and total cyanide were significantly increased with the length time of germination for all cultivars. Fermentation and heat treatment of ger minated seeds significantly reduced cyanide content and only traces we re detected in the final product (Hulu-murr and Merissa). Fermentation alone was found to reduce cyanide content, although not as much as wh en it was accompanied by heat treatment. Diastatic activity markedly i ncreased with time of germination for Feterita and Gadamelhamam cultiv ars while for Waznashra it increased markedly up to day 3 after which it started to decline rapidly. Results indicated that germination of s orghum seeds for different periods increased tannin and cyanide conten ts, while changes in diastatic activity depend on type of cultivar. Tr aditional processing was found to reduce cyanide contents of germinate d seeds. Copyright (C) 1996 Published by Elsevier Science Ltd