Assessment of malting characteristics of different Indian barley cultivars.

ABSTRACT

The impact of malting on composition and malt quality parameters such as diastatic power, α-amylase activity, ß-amylase activity, hot water extract and ß-glucan content were investigated in five different Indian barley cultivars. Protein content of grains increased significantly after malting. Soluble protein content of unmalted grain, which ranged from 3.20-3.93% increased after malting to 4.26-4.85%. Diastatic power of mature grain varied across genotype and their level increased (58.98-81.05 to 115.93-142.45 DP°) after malting. Diastatic power correlated very strongly with protein content (r = 0.90) and strongly with ß-amylase activity (r = 0.74). α-amylase, which was low (0.042-0.189 Ceralpha Unit/g) initially in unmalted grain, was synthesized during germination to the range of 149.42-223.78 Ceralpha Unit/g. The correlation between diastatic power and α-amylase was very weak (r = - 0.04). The levels of ß-amylase in unmalted grain was in the range of 13.97-18.26; that amount got reduced after malting to 12.55-15.97 Betamyl-3 U/g. ß-amylase had a strong positive correlation (r = 0.85) with grain protein. Malted grain which had higher protein content showed very strong negative correlation (r = - 0.86) with hot water extract value. ß-glucan content reduced 70-80% from the initial level, across genotypes.