Influence of barley genetics on beer chemistry, flavor, and flavor stability

2017 Fall.Includes bibliographical references.In the brewing industry, identifying superior ingredients that provide distinct flavors is an important area of research. While the contribution of raw ingredients such as yeast and hops to flavor is well understood, it is currently unclear if different genotypes of barley provide unique flavor to beer. In brewing, barley is malted to provide saccharides and enzymes for fermentation, however the malt also contains thousands of metabolites that may influence flavor. The goals of this study were to determine (i) if there would be metabolite differences among six commercial barley genotypes, (ii) if differences in barley chemistry are reflected in the chemistry of the beer, (iii) if the differences in the beer chemistry impact sensory attributes of beer, through flavor and flavor stability, and (iv) if there are barley and/or malt metabolites that can be markers for beer flavor and/or flavor stability. Six distinct malts were brewed into six beers using a recipe designed to evaluate differences in flavor. The malts were derived from the barley genotypes: Copeland, Expedition, Full Pint, Meredith, Metcalfe and PolarStar were grown and malted in either Canada or the U.S. Metabolomics was used to characterize chemical variation among the six malts and beers using RP-UHPLC-MS, HILIC-MS (non-volatile metabolites), HS/SPME-GC-MS (volatiles), and ICP-MS (metals). The metabolomics analysis detected 5,042 compounds in malt, and 217 were annotated as known metabolites and included amines (20 metabolites), amino acids (36), fatty acids/lipids (40), sugars (11), phenols (30), and others (80). A total of 4,568 compounds were detected in beer and included 246 annotated metabolites and included amines (9), amino acids (37), fatty acids/lipids/fatty acyls (28), sugars (10), phenols (20), esters (89), aldehydes (21), others (31). The chemical profiles of the six malts and beers were evaluated for metabolite variation using principal component analysis (PCA) and analysis of variance (ANOVA). Principal component analysis was conducted on the annotated metabolites and demonstrated that each of the six malts and beers contained unique chemical profiles. ANOVA characterized 150/217 malt metabolites (69.1%) and 150/246 beer metabolites (60.9%) varied among genotype (ANOVA, FDR adjusted p < 0.05). The six beers were evaluated for flavor using a modified Quantitative Descriptive Analysis® (QDA) for 45 sensory traits at 0, 4, and 8 weeks of storage at 13 °C. PCA characterized flavor differences among the six beers at 8 weeks and Full Pint was described as fruity and Meredith as corn chip. The metabolite and sensory data were integrated using two approaches: Spearman's correlation and two-way orthogonal projection to latent structures (O2PLS). The analyses revealed associations between fruity or corn chip flavor in beer with beer purines/pyrimidines, volatile ketones, amines, and phenolics; and malt lipids, saccharides, phenols, amines, and alkaloids. Taken together, these data support a role of barley metabolites in beer flavor and flavor stability. As a raw ingredient, malted barley genotypes should be evaluated for a contribution to flavor, and this may be a future target for plant breeding efforts to selectively improve flavor and flavor stability quality in beer

Genetic basis of barley contributions to beer flavor

13 Pags.- 1 Fig.- 3 Tabls. © 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.Barley malt is critical for the malting, brewing, and distilling industries, as it is one of the main ingredients of beer and some types of spirits. There is growing evidence that barley genotype - via malt - can impact the flavors of beers and spirits. However, information on the barley genes involved in these flavors is lacking. Therefore, we used quantitative trait locus (QTL) mapping of malt quality traits, beer sensory descriptors and metabolic compounds on a biparental population of doubled haploids derived from the cross of the cultivars Golden Promise and Full Pint. Putative candidate genes for QTLs were identified by alignment with the reference barley genome sequence. There were thirty-seven QTLs across all chromosomes except 4H, with three QTL clusters located on 3H (1 cluster) and 5H (2 clusters: mid-5H and end-5H). Those “hotspots” contained QTLs for multiple phenotypes. Several candidate genes that regulate plant metabolism were identified within the QTLs and included HvAlaAT, HvDep1, HvMKK3, HvGA20ox1 and HvGA20ox2. These genes are involved in seed dormancy and plant height. Alleles at these loci, and perhaps at physically linked loci, can have key downstream effects on malting quality, beer flavor, and abundance of volatile metabolites.Research at Oregon State University was supported by the Agricultural Research Foundation Barley Progress Fund. At Colorado State University, research was supported by CSU's College of Agricultural Sciences, with partial support from the American Malting Barley Association.Peer reviewe

Variation in malt metabolite chemistry and impact on malt and beer flavor

2021 Summer.Includes bibliographical references.Growing and malting barley are processes that are imperative to the production of beer and distilled spirits. The rise of craft malting and brewing have provided many opportunities for the "science and art" of manipulating and bending barley to new limits to create new alternatives for the industry in terms of style and flavor. Understanding the mechanisms of how raw ingredients and their interactions influence product quality is critical for any industry. The organoleptic traits of food and beverages are highly discernable by consumers based on flavor (taste and aroma), appearance, and mouthfeel. These organoleptic attributes are variable and define style, drive consumer trends, and therefore influence the decisions regarding traits that are desirable to breed for in crops. There is a gap in the knowledge regarding how genotype, environment, and processing conditions affect the quality and flavor of beer. Understanding the sources of chemical variation among barley varieties can inform on breeding, malting, and production techniques for novel attributes of the final product. The goal of this research is to understand 1) the chemical variation in non-volatiles observed among heirloom barley malts in order to determine if they offer novel chemical traits; 2) the chemistry of malt hot steep extracts and the links between specific metabolites of the hot steep extracts and their resulting sensory attributes; and 3) the chemical and sensorial basis for differences in beer flavor attributed to experimental barley varieties under controlled conditions. Broadly, a comprehensive non-targeted metabolomics approach was utilized for all studies. Study 1: ultra-performance liquid chromatography mass spectrometry (UPLC-MS) for non-volatiles detection, chemical characterization, and multivariate statistical analyses. In Study 2: three metabolomics platforms: UPLC-MS, Gas chromatography mass spectrometry (GC-MS) for detection of volatiles, and headspace solid phase microextraction (HS/SPME) GC-MS, as well as sensory testing, and multivariate statistical analyses. Study 3: HS/SPME-GC-MS for aromatic volatiles detection, sensory analysis (including check-all-that-apply [CATA], qualitative descriptive analysis [QDA], and projective mapping/napping [PM/N]), and both univariate and multivariate statistical analyses. The results of these studies supported the role of barley genetics, environment, and processing in both quality and flavor differences and provided new information on the types of volatile and non-volatile metabolites that can vary due to these factors. Study 1: we concluded that the metabolites detected in this study (e.g. lipids, organic acids) have demonstrated effects on malt quality and flavor and have potential to contribute to novel chemistry to heirloom barley varieties. The widening of genetic diversity through breeding and introduction of the novel metabolite chemistry traits can allow maltsters and brewers access to more varieties with unique and improved traits. Study 2: the data highlight the utility of the hot steep extract to differentiate malt for flavor and chemistry and indicate specific compounds that drive the most dominant flavors observed in a population of pale malts. These research findings support the value of sensory assessments of malt hot steeps when assessing the quality of malt, defect elimination, and potential for flavor development for craft malts. Study 3: the data supported the role of barley genetics in beer flavor and provided new information on the types of volatile metabolites that can vary in controlled systems. This research could be useful in prediction of flavor based on variety, malting, and brewing analytics. Predictions regarding variation in metabolites could be useful in variety development, selection of varieties for specific beer styles, and malting or brewing protocol design

Variation in quality of grains used in malting and brewing.

Cereal grains have been domesticated largely from food grains to feed and malting grains. Barley (Hordeum vulgare L.) remains unparalleled in its success as a primary brewing grain. However, there is renewed interest in "alternative" grains for brewing (and distilling) due to attention being placed on flavor, quality, and health (i.e., gluten issues) aspects that they may offer. This review covers basic and general information on "alternative grains" for malting and brewing, as well as an in-depth look at several major biochemical aspects of these grains including starch, protein, polyphenols, and lipids. These traits are described in terms of their effects on processing and flavor, as well as the prospects for improvement through breeding. These aspects have been studied extensively in barley, but little is known about the functional properties in other crops for malting and brewing. In addition, the complex nature of malting and brewing produces a large number of brewing targets but requires extensive processing, laboratory analysis, and accompanying sensory analysis. However, if a better understanding of the potential of alternative crops that can be used in malting and brewing is needed, then significantly more research is required