Grain hordein content and malt quality as affected by foliar nitrogen fertilisation at heading

Abstract

Nitrogen fertilisation at heading is a practice for increasing grain protein content in malting barley. The objective of this study was to assess the effects of fertilisation on grain protein, the content and composition of hordeins, and relationship to malt quality. In 25 field experiments in the Argentine Pampas, the effect of foliar nitrogen fertilisation at heading on the grain protein content was evaluated. In five experiments, the content and composition of hordeins and some malting quality indices was assessed. Nitrogen fertilisation at heading increased grain protein content, hordein content and the proportion of hordein C, and decreased the proportion of hordein B. In addition, malts obtained from the grains of the crops fertilised with nitrogen at heading had lower extract and higher hardness than those obtained without fertilisation. Malt extract was negatively associated with total hordein (or protein) content and positively with grain size. The inclusion of the fractions into which hordeins are classified did not improve the explanatory models for malt extract. Therefore, the composition of hordein does not seem to be a determining factor for malt extract when comparing samples with and without nitrogen fertilisation at heading. © 2021 The Institute of Brewing & Distilling

Can Seaweed Extract Improve Yield and Quality of Brewing Barley Subjected to Different Levels of Nitrogen Fertilization?

“…Despite these positive features related to nitrogen fertilization, this is a practice requiring careful management, because the malting industry requires a protein content in barley grains ranging between 10 and 11% [15]. The nitrogen content in barley grain is closely linked to N rate; several studies reported an increase in protein content when the nitrogen rate increases [29,30].…”

“…In brief, the main steps of the malting process are as follows: (i) water absorption (swelling); (ii) germination; (iii) stoving with hot air for germination interruption; and (iv) stabilization of malted grain [12]. The quality of malting barley depends on many factors, such as biological, environmental, and technological factors [13,14], but the protein content in grains is the crucial factor of the malting quality [15]. Indeed, when grains are low in protein content, brewing performance may be reduced due to low enzyme activity and poor yeast nutrition [16,17]; instead, grains with a higher protein content determine a malt with a lower extract yield [18].…”

“…Indeed, when grains are low in protein content, brewing performance may be reduced due to low enzyme activity and poor yeast nutrition [16,17]; instead, grains with a higher protein content determine a malt with a lower extract yield [18]. Therefore, the malting industry requires barley grains with an intermediate protein content, at an optimal range between 10 and 11% [15]. Malt extract is also positively associated with grain size [18], which is one of the most important parameters in the process of grain selection by the malting industry.…”

Understanding the influence of genotype and temperature on proteolytic activity in distinct barley genotypes

“…The malting industry requires barley grains with protein content in an optimal range between 10% and 11% (Prystupa et al., 2021). Proteins can have some obvious effects on enzymatic degradation of starch, such as by physically hindering access of degradation enzymes to starch.…”

The potential of crop models in simulation of barley quality traits under changing climates: A review

“…Quality traits of grains can be defined by physical and compositional properties, with thresholds based on end-use essentials (Nuttall et al, 2017). The crude protein content is the most crucial element specifying barley's quality for such industries as a function of grain nitrogen content (Prystupa et al, 2021). The high protein level in barley reduces the starch content leading to a lower alcohol level; nevertheless, yeast activity is restricted by nitrogen shortage under lower grain protein levels (Pettersson and Eckersten, 2007).…”