J. Am. Soc. Brew. Chem. 75(4): [345][346][347][348][349][350][351][352][353] 2017 This research tested the hypothesis that barley genotype can affect beer flavor and assessed the relative contributions of genotype and location to beer sensory descriptors. Golden Promise, Full Pint, 34 of their doubled haploid progeny, and CDC Copeland were grown at three locations in Oregon, U.S.A. Grain from these trials was micromalted and the resulting malts used for nano-brewing. Sensory evaluations were conducted on the nano-brews. Barley genotype had significant effects on many sensory descriptors. The most significant sensory descriptorswhen comparing barley genotypes-were cereal, color, floral, fruity, grassy, honey, malty, toasted, toffee, and sweet. Golden Promise was significantly higher in fruity, floral, and grassy flavors, whereas Full Pint was significantly higher in malty, toffee, and toasted flavors. CDC Copeland was closest to neutral for most flavor traits. There were notable differences for some descriptors between locations. New combinations of parental flavor attributes were observed in the progeny. Multitrait analysis revealed regions of the barley genome with significant effects on malting quality and flavor traits. These findings are, of course, applicable only to the barley germplasm tested, the environment sampled, and the protocols used for micromalting and brewing. The necessary largerscale experiments involving optimized malts and larger volumes of beer are in process.

Previous research demonstrates that barley genetics can influence beer flavor. However, the chemical basis for differences in beer flavor attributed to barley is not well defined. Here, the associations between beer volatile compounds and sensory descriptors were investigated in a controlled experiment, whereby barley genotype was the main driver of variation in the system. Beer was brewed from three advanced barley breeding lines and compared to a CDC Copeland control. Sensory studies were performed via three independent panels (a consumer, brewery, and laboratory panel). The results suggest that the four beer samples have distinct flavor profiles that could be discriminated by the three sensory panels. Volatile compounds for the four beers were characterized using HS/SPME-GC-MS; quantitation and annotation were performed using a non-targeted metabolomics approach on 397 detected compounds. The O2PLS data analysis supports that alkane/alkenes, benzenoids, amides/amines, and fatty acid esters were associated with the most desirable lager traits, compared to Maillard Reaction Products that were more abundant in the beers with "non-ideal" lager traits. Taken together, these data further support the role of barley genetics in beer flavor and provide new information on the types of volatile metabolites that can vary in controlled systems.ABBREVIATIONS: ANOVA: analysis of variance; HS/SPME-GC-MS: headspace solid-phase microextraction gas chromatography mass spectrometry; O2PLS: orthogonal partial least squares; PCA: principal component analysis.

Based on prior research that showed significant genetic differences between barley genotypes for beer sensory descriptors, the effects of degree of malt modification on these descriptors were assessed in two experiments. The first experiment involved sensory assessment of nano-beers made from micromalts of Golden Promise, Full Pint, 34 doubled haploid progeny, and the check CDC Copeland. Average degree of modification was assessed by sampling grain from each of the 37 genotypes stored for three postharvest intervals prior to malting and brewing. The second experiment involved sensory assessment of pilot beers made from intentionally under-, properly, and overmodified pilot malts of two barley varieties: Full Pint and CDC Copeland. In both experiments, genotypes were the principal sources of significant variation in sensory descriptors. Degree of modification and genotype × modification interactions were also significant for some descriptors. Based on the results of this study, the genetic characterization of and selection for barley contributions to beer flavor are warranted, even with undermodified malts. The contribution of barley variety to beer flavor will likely be modest compared with the flavors developed during the malting process and the flavors contributed by hops and yeast. However, in certain beer styles, the contributions of barley genotype may be worth the attention of maltsters, brewers, and consumers.

This study was conducted to document the extent and basis of compositional variation of shoot biomass of the energy Sorghum bicolor hybrid TX08001 during development under field conditions. TX08001 is capable of accumulating ~40 Mg/ha of dry biomass under good growing conditions and this genotype allocates ~80% of its shoot biomass to stems. After 150 days of growth TX08001 stems had a fresh/dry weight ratio of ~3:1 and soluble biomass accounted for ~30% of stem biomass. A panel of diverse energy sorghum genotypes varied ~6-fold in the ratio of stem structural to soluble biomass after 150 days of growth. Near-infrared spectroscopic analysis (NIRS) showed that TX08001 leaves accumulated higher levels of protein, water extractives and ash compared to stems, which have higher sugar, cellulose, and lignin contents. TX08001 stem sucrose content varied during development, whereas the composition of TX08001 stem cell walls, which consisted of ~45–49% cellulose, ~27–30% xylan, and ~15–18% lignin, remained constant after 90 days post emergence until the end of the growing season (180 days). TX08001 and Della stem syringyl (S)/guaiacyl (G) (0.53–0.58) and ferulic acid (FA)/para-coumaric acid (pCA) ratios were similar whereas ratios of pCA/(S+G) differed between these genotypes. Additionally, an analysis of irrigated versus non-irrigated TX08001 revealed that non-irrigated hybrids exhibited a 50% reduction in total cell wall biomass, an ~2-fold increase in stem sugars, and an ~25% increase in water extractives relative to irrigated hybrids. This study provides a baseline of information to help guide further optimization of energy sorghum composition for various end-uses.

One option to achieving greater resiliency for barley production in the face of climate change is to explore the potential of winter and facultative growth habits: for both types, low temperature tolerance (LTT) and vernalization sensitivity are key traits. Sensitivity to short-day photoperiod is a desirable attribute for facultative types. In order to broaden our understanding of the genetics of these phenotypes, we mapped quantitative trait loci (QTLs) and identified candidate genes using a genome-wide association studies (GWAS) panel composed of 882 barley accessions that was genotyped with the Illumina 9K single-nucleotide polymorphism (SNP) chip. Fifteen loci including 5 known and 10 novel QTL/genes were identified for LTT—assessed as winter survival in 10 field tests and mapped using a GWAS meta-analysis. FR-H1, FR-H2, and FR-H3 were major drivers of LTT, and candidate genes were identified for FR-H3. The principal determinants of vernalization sensitivity were VRN-H1, VRN-H2, and PPD-H1. VRN-H2 deletions conferred insensitive or intermediate sensitivity to vernalization. A subset of accessions with maximum LTT were identified as a resource for allele mining and further characterization. Facultative types comprised a small portion of the GWAS panel but may be useful for developing germplasm with this growth habit.