THE USE OF INFRA RED REFLECTANCE FOR THE RAPID ESTIMATION OF THE SOLUBLE β‐GLUCAN CONTENT OF BARLEY

Abstract

It has previously been reported that the malting quality of barley is related to the amount of β‐glucan dissolved at low pH under defined conditions. An infra red reflectance instrument, the ‘InfraAlyzer’, can be used to estimate this ‘acid‐soluble’ β‐glucan content of barley. This is a rapid test (approximately one min/sample) and is therefore suitable when screening for low soluble β‐glucan in the early generations of malting quality breeding programmes. The relationship between predicted and measured values for soluble β‐glucan differs from comparisons made for other quality components in forages, in that it is curvilinear rather than linear. A logarithmic transformation of the soluble β‐glucan values, however, allows the current ‘InfraAlyzer’, which produces linear regressions only, to predict values for soluble β‐glucan that correlate well (r = 0.87) with the measured results. 1978 The Institute of Brewing & Distilling