Chemical Composition in Barley Grains and Malt Quality

Performance, metabolism, and meat quality of broilers fed dry brewery residue

A study was conducted to assess the chemical composition and apparent metabolizable energy (AME), nitrogen-corrected AME (AMEn), and their respective coefficients of dry brewery residue (DBR) for broilers. A second study was conducted to evaluate the increasing inclusions of DBR in broiler diets and its effects on growth performance, carcass traits, blood metabolites, and meat quality. In the first trial (metabolism assay), a total of 250 male broilers were assigned to 5 diets (0, 100, 200, 300, and 400 g DBR/kg) composed by 5 replications with 10 animals per cage in a completely randomized design in the period from days 11 to 21. There was an increasing linear effect for AME, AMEn, metabolizable coefficient of gross energy (MCGE), and MCGE corrected for N (MCGEn). In the second experiment, a total of 840 one-day-old male broiler chickens were assigned to 6 treatments (0, 20, 40, 60, 80, and 100 g DBR/kg) with 7 replications and 20 animals per pen, from days 0 to 42. Growth performance was determined at days 21 and 42. There was an increasing linear effect for weight gain in the period from days 0 to 21 and for feed intake from days 0 to 42. A linear decreasing effect was observed at day 21 for cholesterol and quadratic effect for uric acid (UA), aspartate aminotransferase, and albumin. At day 42, there was a quadratic effect for UA and creatinine. At day 21, an increasing linear effect was observed for protein deposition rate. In conclusion, the inclusion of DBR up to 100 g/kg improved WG in the starter phase and did not negatively affect the productive parameters of broilers from days 0 to 42.

In vitro airway models from mice, rhesus macaques, and humans maintain species differences in xenobiotic metabolism and cellular responses to naphthalene

The translational value of high-throughput toxicity testing will depend on pharmacokinetic validation. Yet, popular in vitro airway epithelia models were optimized for structure and mucociliary function without considering the bioactivation or detoxification capabilities of lung-specific enzymes. This study evaluated xenobiotic metabolism maintenance within differentiated air-liquid interface (ALI) airway epithelial cell cultures (human bronchial; human, rhesus, and mouse tracheal), isolated airway epithelial cells (human, rhesus, and mouse tracheal; rhesus bronchial), and ex vivo microdissected airways (rhesus and mouse) by measuring gene expression, glutathione content, and naphthalene metabolism. Glutathione levels and detoxification gene transcripts were measured after 1-h exposure to 80 µM naphthalene (a bioactivated toxicant) or reactive naphthoquinone metabolites. Glutathione and glutathione-related enzyme transcript levels were maintained in ALI cultures from all species relative to source tissues, while cytochrome P450 monooxygenase gene expression declined. Notable species differences among the models included a 40-fold lower total glutathione content for mouse ALI trachea cells relative to human and rhesus; a higher rate of naphthalene metabolism in mouse ALI cultures for naphthalene-glutathione formation (100-fold over rhesus) and naphthalene-dihydrodiol production (10-fold over human); and opposite effects of 1,2-naphthoquinone exposure in some models-glutathione was depleted in rhesus tissue but rose in mouse ALI samples. The responses of an immortalized bronchial cell line to naphthalene and naphthoquinones were inconsistent with those of human ALI cultures. These findings of preserved species differences and the altered balance of phase I and phase II xenobiotic metabolism among the characterized in vitro models should be considered for future pulmonary toxicity testing.

Quality attributes for barley malt: "The backbone of beer"

Malting is the process of preparing barley for brewing through partial germination followed by drying. This process softens the grain cell wall and stimulates the production of diastatic enzymes, which convert starch into malt extract. The suitability of a barley grain for malt production depends upon a large number of quality parameters that are crucial for the identification and release of high-quality malt varieties. Maintaining tight control of these quality attributes is essential to ensure high processing efficiency and final product quality in brewery and malt house. Therefore, we have summarized the basic malting process and various physiological and biochemical quality parameters that are desirable for better malt quality. This study may provide an understanding of the process, problems faced, and opportunities to maltsters and researchers to improve the malt efficiency by altering the malting process or malt varieties.

Assessment of malting characteristics of different Indian barley cultivars

The impact of malting on composition and malt quality parameters such as diastatic power, α-amylase activity, β-amylase activity, hot water extract and β-glucan content were investigated in five different Indian barley cultivars. Protein content of grains increased significantly after malting. Soluble protein content of unmalted grain, which ranged from 3.20-3.93% increased after malting to 4.26-4.85%. Diastatic power of mature grain varied across genotype and their level increased (58.98-81.05 to 115.93-142.45 DP°) after malting. Diastatic power correlated very strongly with protein content (r = 0.90) and strongly with β-amylase activity (r = 0.74). α-amylase, which was low (0.042-0.189 Ceralpha Unit/g) initially in unmalted grain, was synthesized during germination to the range of 149.42-223.78 Ceralpha Unit/g. The correlation between diastatic power and α-amylase was very weak (r = - 0.04). The levels of β-amylase in unmalted grain was in the range of 13.97-18.26; that amount got reduced after malting to 12.55-15.97 Betamyl-3 U/g. β-amylase had a strong positive correlation (r = 0.85) with grain protein. Malted grain which had higher protein content showed very strong negative correlation (r = - 0.86) with hot water extract value. β-glucan content reduced 70-80% from the initial level, across genotypes.

Morphology, Carbohydrate Distribution, Gene Expression, and Enzymatic Activities Related to Cell Wall Hydrolysis in Four Barley Varieties during Simulated Malting

Many biological processes, such as cell wall hydrolysis and the mobilisation of nutrient reserves from the starchy endosperm, require stringent regulation to successfully malt barley (Hordeum vulgare) grain in an industrial context. Much of the accumulated knowledge defining these events has been collected from individual, unrelated experiments, and data have often been extrapolated from Petri dish germination, rather than malting, experiments. Here, we present comprehensive morphological, biochemical, and transcript data from a simulated malt batch of the three elite malting cultivars Admiral, Navigator, and Flagship, and the feed cultivar Keel. Activities of lytic enzymes implicated in cell wall and starch depolymerisation in germinated grain have been measured, and transcript data for published cell wall hydrolytic genes have been provided. It was notable that Flagship and Keel exhibited generally similar patterns of enzyme and transcript expression, but exhibited a few key differences that may partially explain Flagship's superior malting qualities. Admiral and Navigator also showed matching expression patterns for these genes and enzymes, but the patterns differed from those of Flagship and Keel, despite Admiral and Navigator having Keel as a common ancestor. Overall (1,3;1,4)-β-glucanase activity differed between cultivars, with lower enzyme levels and concomitantly higher amounts of (1,3;1,4)-β-glucan in the feed variety, Keel, at the end of malting. Transcript levels of the gene encoding (1,3;1,4)-β-glucanase isoenzyme EI were almost three times higher than those encoding isoenzyme EII, suggesting a previously unrecognised importance for isoenzyme EI during malting. Careful morphological examination showed that scutellum epithelial cells in mature dry grain are elongated but expand no further as malting progresses, in contrast to equivalent cells in other cereals, perhaps demonstrating a morphological change in this critical organ over generations of breeding selection. Fluorescent immuno-histochemical labelling revealed the presence of pectin in the nucellus and, for the first time, significant amounts of callose throughout the starchy endosperm of mature grain.

Proteomic Analysis Reveals Key Proteins and Phosphoproteins upon Seed Germination of Wheat (Triticum aestivum L.)

Wheat (Triticum aestivum L.) is one of the oldest cultivated crops and the second most important food crop in the world. Seed germination is the key developmental process in plant growth and development, and poor germination directly affects plant growth and subsequent grain yield. In this study, we performed the first dynamic proteome analysis of wheat seed germination using a two-dimensional differential gel electrophoresis (2D-DIGE)-based proteomic approach. A total of 166 differentially expressed protein (DEP) spots representing 73 unique proteins were identified, which are mainly involved in storage, stress/defense/detoxification, carbohydrate metabolism, photosynthesis, cell metabolism, and transcription/translation/transposition. The identified DEPs and their dynamic expression profiles generally correspond to three distinct seed germination phases after imbibition: storage degradation, physiological processes/morphogenesis, and photosynthesis. Some key DEPs involved in storage substance degradation and plant defense mechanisms, such as globulin 3, sucrose synthase type I, serpin, beta-amylase, and plastid ADP-glucose pyrophosphorylase (AGPase) small subunit, were found to be phosphorylated during seed germination. Particularly, the phosphorylation site Ser(355) was found to be located in the enzyme active region of beta-amylase, which promotes substrate binding. Phosphorylated modification of several proteins could promote storage substance degradation and environmental stress defense during seed germination. The central metabolic pathways involved in wheat seed germination are proposed herein, providing new insights into the molecular mechanisms of cereal seed germination.

Discovery of novel Bmy1 alleles increasing β-amylase activity in Chinese landraces and Tibetan wild barley for improvement of malting quality via MAS

China has a large barley germplasm collection which has not been well characterized and is therefore underutilized. The Bmy1 locus encoding the β-amylase enzyme on chromosome 4H has been well characterized in the worldwide barley germplasm collections due to its importance in the malting and brewing industry. The Bmy1 locus was chosen as an indicator to understand genetic potential for improvement of malting quality in Chinese landraces and Tibetan wild barley. The genetic diversity of 91 barley accessions was assessed using allele specific Multiplex-ready molecular markers. Eight accessions were further sequenced, based on the Multiplex-ready marker diversity for Bmy1 in the germplasm. Six of the eight accessions clustered together in a unique group, and showed similarities to ‘Haruna Nijo’, wild barley accession PI296896 and ‘Ashqelon’. Sequence comparisons with the known Bmy1 alleles identified not only the existing 13 amino acid substitutions, but also a new substitution positioned at A387T from a Chinese landrace W127, which has the highest β-amylase activity. Two new alleles/haplotypes namely Bmy1-Sd1c and Bmy1-Sd5 were designated based on different amino acid combinations. We identified new amino acid combination of C115, D165, V233, S347 and V430 in the germplasm. The broad variation in both β-amylase activity and amino acid composition provides novel alleles for the improvement of malting quality for different brewing styles, which indicates the high potential value of the Chinese landraces and Tibetan wild barley.