Effects of Grain and Malt â-Glucan on Distilling Quality in a Population of Hull-less Barley

Abstract

A population of barley lines, derived by mutation in the hull-less variety, Penthouse, was included in a replicated trial, along with Penthouse and the hulled malting cultivar, Optic. Samples were assessed for a range of grain quality traits, then malted, with germination for either 4 or 5 days, prior to kilning. Most lines had grain β-glucan contents lower than that of Penthouse, but there was no significant correlation between grain and malt β-glucan content. Malt β-glucan levels were indicative of differences in cell wall breakdown between 4 and 5 days germination, but negative associations with distilling parameters Extract and Alcohol Yield, were not statistically significant. It was concluded that the lines differed in the rate and extent of cell wall breakdown and that grain shape may influence modification in distal parts of the grain. However, a malting regime, optimised to suit Optic may be less suited to discriminating between hull-less lines of reasonable quality.