Changes in β‐glucan and other carbohydrate components of barley during malting

Changes in total (1→3), (1→4)‐β‐glucan content were followed during the micro‐malting of nine varieties of barley with a wide range of malting qualities. These changes were related to estimates of endosperm modification based upon staining with Calcofluor. β‐Glucan content declined from an average of 3.54% in the barley to 0.75% in the malt. Pentosan and total starch (including starch‐derived oligosaccharides) levels showed comparatively little change during malting. β‐Glucan composition of the barley was a poor indicator of malting performance. However, the β‐glucan, starch and xylose contents of the malt all showed significant correlations with malt extract. Estimation of malt β‐glucan content gave the best indication of malt quality. Direct determination of β‐glucan may be of more value in assessing malt quality than indirect techniques based upon assessing modification of stained grains.