Triticeae Genomics and Genetics, 2024, Vol.15, No.5, 266-276 http://cropscipublisher.com/index.php/tgg 271 adequately broken down (Gupta et al., 2010). Therefore, selecting barley varieties with high enzymatic activity and low levels of non-starch polysaccharides is essential for achieving high saccharification efficiency and producing high-quality wort (Gupta et al., 2010; Fox and Bettenhausen, 2023). 4.3 Selection for specific traits The development of barley varieties suitable for beer fermentation involves targeted selection and breeding to enhance specific traits. Breeding programs focus on improving traits such as kernel uniformity, enzyme activity, and disease resistance to ensure consistent malt quality and brewing performance (Ramsay et al., 2011). For instance, the selection of barley with high levels of α-amylase and β-amylase is prioritized to enhance starch conversion during mashing, while breeding for lower protein content helps in producing clearer beers with better stability (Gupta et al., 2010). Genetic studies have identified key genes, such as VRS1 and INTERMEDIUM-C (INT-C), that control important traits in barley, including row number and spikelet fertility. These genes have been manipulated through breeding to develop varieties with desirable characteristics for brewing (Ramsay et al., 2011). For example, the VRS1 gene is responsible for the two-row or six-row phenotype, and its alleles can be selected to produce barley with the preferred row type for specific brewing applications (Palmer et al., 2009; Ramsay et al., 2011). Additionally, the INT-C gene, an ortholog of the maize domestication gene TEOSINTE BRANCHED 1, has been shown to modify lateral spikelet fertility, further influencing the yield and quality of barley for brewing (Ramsay et al., 2011). Through such targeted breeding efforts, barley varieties with optimized traits for beer fermentation are continuously developed to meet the evolving needs of the brewing industry. 5 Application of Malting Barley in the Brewing Process: Saccharification and Fermentation 5.1 Role in the saccharification process Barley serves as a crucial starch source in the brewing process. During saccharification, the starches present in barley grains undergo biochemical transformations to produce fermentable sugars. The malting process activates various enzymes, such as α-amylase and β-amylase, which break down the starches into simpler sugars. These enzymes play a pivotal role in converting the complex carbohydrates in barley into maltose and other fermentable sugars, which are essential for the subsequent fermentation process (Gupta et al., 2010; Kok et al., 2018). The structural characteristics of barley starch, including its chain-length distributions and molecular size distributions, significantly influence the efficiency of saccharification and the quality of the resulting wort (Yu et al., 2020). 5.2 Contribution to the fermentation process The fermentable sugars derived from barley during saccharification are vital for the fermentation process. These sugars are metabolized by yeast to produce alcohol, carbon dioxide, and various flavor compounds. The type and concentration of fermentable sugars influence the flavor, texture, and alcohol content of the final beer product. For instance, maltose, the primary sugar produced during saccharification, is readily fermentable by yeast and contributes to the beer's alcohol content and overall flavor profile (Kok et al., 2018; Yu et al., 2020). Additionally, the presence of non-fermentable dextrins, which are also products of starch hydrolysis, can affect the mouthfeel and perceived fullness of the beer (Yu et al., 2020). 5.3 The role of barley enzymes in fermentation Barley enzymes, particularly α-amylase and β-amylase, are integral to the saccharification of malt. α-Amylase breaks down starch molecules into smaller dextrins, while β-amylase further hydrolyzes these dextrins into maltose. These enzymatic activities are crucial for producing a wort rich in fermentable sugars, which are necessary for efficient yeast fermentation (Gupta et al., 2010; Kok et al., 2018). The activity of these enzymes can be influenced by the malting and mashing conditions, which in turn affect the overall efficiency of the brewing process and the quality of the beer (Kok et al., 2018). Understanding the molecular interactions between starch and amylolytic enzymes can help brewers optimize the brewing process to achieve desired beer qualities (Yu et al., 2020).
RkJQdWJsaXNoZXIy MjQ4ODYzNQ==