Comparative studies of the development of endosperm-degrading enzymes in malting sorghum and barley

Abstract

The endosperm cell walls of barley are degraded extensively during malting whilst those of sorghum are not. Malting barley produced endo-β-1,3:1,4-glucanase, endo-β-1,3-glucanase and pentosanase in large quantities. In contrast, malting sorghum developed mainly endo-β-1,3-glucanase and pentosanase. Although the limited break-down of the endosperm cell walls of sorghum may reflect sub-optimal activities of β-glucanases, such as endo-β-1,3:1,4-glucanases, it is possible that the highly intractable nature of the cell walls and their high protein content (approx. 60%) may contribute to the low susceptibility of sorghum endosperm cell walls to enzymic degradation during malting.

Properties of Three Sorghum Cultivars Used for the Production of Bili-Bili Beverage in Northern Cameroon

“…In terms of malting conditions in the three localities, the ␣-amylase potential of the malts was better under laboratory conditions at ICBD than under local conditions at Mindjil and Yagoua (Tables V, VI). The low ␤-amylase potential of sorghum has been confirmed by these studies 7,8,18 . Poor degradation of ␤-glucans during malting and poor hydrolysis of starch during mashing can lead to slow wort filtration, reduced extraction efficiency, and haze formation in beers 18 .…”

“…Mashing was carried out by the decantation process where separated, enzyme-active worts were used to convert the gelatinized starch of the mash 2,3,8,18 . Duplicates of about 52 g of sorghum malt were ground (disc setting at 0.7 mm) using a Buhler Universal Laboratory Disc Mill (type DLFU) and 50 g weighed into a mashing beaker which was placed into a mashing bath attemperated to 45°C.…”

Effect of Amyloglucosidase on Wort Composition and Fermentable Carbohydrate Depletion in Sorghum Lager Beers

“…Other authors have also reported similar differences 9,11,13,17 . Etokakpan and Palmer 13,14 observed that BM (75°L) had 5 times more diastatic power and its endosperm cell walls were degraded more extensively during malting than SM (15°L). Taylor 27 and Daiber and Taylor 11 concluded that BM has a 6°C lower gelatinization temperature, about 3 and 4 times more diastatic and ␤-amylase activities than SM.…”

Mashing Studies with Unmalted Sorghum and Malted Barley

“…Demuyakor et al 14 found that ␤-glucan levels in sorghum malt extract were very low compared with barley malt extract. Etokakpan and Palmer 15 observed that filtration of sorghum beer was not related to the ␤-glucan content but rather to its composition. For 0%, 20% and 40% sorghum mashes the viscosity of the resultant wort significantly decreased as the amount of sorghum was increased (Table III) (p < 0.01).…”