Structural and enzymic changes in germinated barley and rye

Germination of barley and rye grains at 15 degreesC and 56% moisture conten t resulted in the production of alpha -amylase, beta -glucanase, endo-beta -xylanase and alpha -arabinosidase. During germination of rye, enzyme activ ity increased significantly after the first day, whereas in the case of bar ley a rapid increase was not observed until after the third or fourth day. Rye varieties produced more xylanase, whereas barley produced more alpha -a mylase and beta -glucanase. Of the barley samples, germinated Pokko had the highest activities of beta -glucanase, xylanase and alpha -amylase, and at 46% moisture content highest degradation of cell walls on the basis of ima ge analysis. Arve had the highest alpha -arabinofuranosidase activity. Of t he rye samples, Amando produced more xylanase and alpha -arabinosidase than Anna. The M-w of barley and rye beta -glucan decreased significantly durin g germination. In rye samples, residual high molecular weight arabinoxylans were still present after 4 days of germination. The mass average molecular weight (M-w) of this fraction was 3 x 10(6).