Some Relationships Between Malted Barleys of Different Nitrogen Levels and the Wort Properties

R.C. Agu ^1
1Scotmalt Ltd, The Malt Extract Factory, Kirkliston, West Lothian, Edinburgh, Scotland. Corresponding author. E-mail: reginald_agu@hotmail.com

J. Inst. Brew. 109(2), 106-109, 2003  |   VIEW ARTICLE

ABSTRACT
Barleys containing different levels of total nitrogen seem to have similar initial patterns for endosperm modification during malting. The higher nitrogen barley had a slower rate of endosperm modification, whilst the lower nitrogen barley had a faster rate of endosperm modification as germination progressed. Although the higher nitrogen barley had slower rate of endosperm modification, it transferred more nitrogen materials to the roots and shoots, whilst the lower nitrogen barley transferred less nitrogen materials to the roots and shoots. The higher nitrogen barley produced a lower yield of extract, but released higher levels of soluble nitrogen, free amino nitrogen (FAN) and peptides in the extract. The lower nitrogen barley produced a higher yield of extract and higher levels of carbohydrates (reducing sugars) in the extract. These results suggest that other important relationships exist between barleys of different nitrogen content. A drop in peptide nitrogen occurred on the same day of germination in both barley samples.

Key words:
Barley, carbohydrates, malting, nitrogen, peptide, soluble nitrogen.

Publication no. G-2003-0604-112  ^©2003 The Institute & Guild of Brewing