Malting quality of a hulless/covered doubled haploid barley population

Abstract

The potential to improve malting quality of hulless barley was investigated with a two-row doubled haploid population (TR251/HB345). TR251 is a covered, malt breeding line with good malting potential while HB345 is a hulless line with good agronomic traits and the gene for heat stable -amylase (sd2H). Barley grown in standard yield test plots at Brandon, Manitoba during 2002 was micromalted and analysed using standard conditions. The 62 hulless lines, on average, had significantly higher levels of malt extract than the 62 covered lines. A significantly lower percentage of the hulless extract was fermentable but the hulless lines still fermented a greater amount of total extract. Levels of diastatic power were similar among hulless and covered malts but -amylase was significantly lower in the hulless lines. Heat stable -amylase improved fermentability but not significantly. Samples showed an acceptable degree of malt modification but -glucan levels still had a negative effect on fermentability. Levels of total free amino acids were similar among hulless and covered worts; however, levels of several individual amino acids were significantly lower in the hulless worts which had a negative effect on fermentability. In summary, hulless malt had some superior attributes compared to covered malt but increased levels of some specific enzymes would further enhance its appeal.