Effects of malting conditions on the amino acid compositions of final malt

Abstract

Barley has been widely used for the production of malt in the brewing industry. Malt was the main raw material indispensable for beer brewing. The fermentability of malt wort is dependent on an adequate supply of the essential nutrients required by yeast. The amino acid content is an important malt parameter to the yeast growth and metabolism in malt wort. To increase brewing fermentability and efficiency, malts with high levels of free amino nitrogen and amino acids are essential. However, the barley variety and malting conditions affecting this supply of nutrients are not well understood. The aims of this study were to determine the amino acid and malt quality parameters of barley varieties (Harrington, GanIII, Esterel and Kendall) changed during germination and final malt and investigate the amino acid composition of barley copeland in three malting programs. The contents of twenty amino acids during germination and in the final malt stage were determined using a reverse-phase high-performance liquid chromatography (RP-HPLC) method. Total amino acid had high positive
correlation with free amino nitrogen (0.9354), Kolbach index (0.9719) and soluble protein (0.8316) in final malt. This study identified various important malting conditions that may lead to improvements in malt
quality and thus enhancements in beer flavor. The optimal malting program of barley is a malting process that can provide desirable amino acid contents.

Keywords: Malting program, amino acid, barley variety