FACTORS INFLUENCING THE HARDNESS (MILLING ENERGY) AND MALTING QUALITY OF BARLEY

Abstract

The hardness of samples of 41 barley cultivars grown in Australia was determined by measuring milling energy. The milling energy was negatively correlated (r= −0.49) with the starch and positively correlated (r=0.50) with the β-glucan content. The correlation with protein content was not significant. This suggests that a low starch content and a high β-glucan content may contribute to hardness but other factors may probably also be involved. The extent of modification of these barley samples measured by Calcofluor staining after steeping and 48 h of germination was correlated with the grain hardness (r= −0.56). Factors contributing to grain hardness may limit the rate of endosperm modification during malting, indicating the value of selecting softer cultivars for malting.