Compounds In Barley Research Articles

Exploring the therapeutic potential of barley grain in type 2 diabetes management: a review

SummaryA healthy lifestyle with a high intake of whole grains is preferred for the effective type 2 diabetes mellitus (T2DM) prevention. Plenty of studies have shown the health benefits of barley on metabolic diseases, but there is a dearth of review articles specifically focused on antidiabetic effects. Hence, it is urgent to consolidate the up‐to‐date findings and provide guidance for future research endeavours in a timely review. This review aims to provide an overview on barley consumption for T2DM prevention and management, focusing on certain key aspects such as glycaemic control, insulin sensitivity and lipid profile. Extensive research has highlighted the potential benefits of barley grains in T2DM prevention, attributed to their high dietary fibre content, a diverse array of phytochemicals, and bioactive peptides. The dietary fibre (e.g., β‐glucan and arabinoxylan), characterised by their viscous and water‐soluble nature, is involved in modulating gastrointestinal physiology, thereby exerting regulatory effects on blood glucose and insulin levels. Phenolic compounds in barley have the potential to inhibit α‐amylase and α‐glucosidase enzymes, offering further support for glucose homeostasis. In addition, outer layers of barley are found to have high levels of fibres and bioactive compounds. The levels of these bioactive compounds can be improved through food processing techniques. Future investigation is necessary to establish the relationships between barley bioactive components and their specific antidiabetic capacity to improve study consistency and innovative strategies to incorporate barley into daily diet.

Endogenic Phenolic Compounds of Barley as Potential Biomarkers Related to Grain Mycotoxin Production and Cultivar Selection.

Barley (Hordeum vulgare L.) is the fourth largest cereal crop in the world. One of the most devastating diseases in barley worldwide is Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe. Several mycotoxins are produced by FHB infection, and deoxynivalenol (DON) is one of them responsible for the deterioration of grain quality. The current limited number of reliable molecular markers makes the development of FHB-resistant cultivars rather difficult and laborious. Moreover, there is a limited number of designed specific biomarkers that could distinguish the FHB resistance and mycotoxin accumulation in barley cultivars. This study investigated the phenolic compounds of ten different Canadian barley cultivars, grown in artificially FHB-infected and non-infected field trials. The enzyme-linked immunosorbent assay (ELISA) was used to assess the presence of DON in the harvested infected grains of each tested variety. High-performance liquid chromatography (HPLC) analysis was performed using both infected and non-infected samples. We identified differences among cultivars tested in non-infected samples through quantitative analysis of free and bound phenolic compounds. The resistant cultivars showed higher amounts of major bound phenolic compounds compared to the susceptible check CDC Bold. Additionally, the FHB-infected cultivars produced significantly higher amounts of sinapic acid (SIN) () and catechin (CAT) in the soluble free form of phenolics in barley compared to the non-infected subjects. This study suggests that phenolic compounds in barley could allow barley breeders to precisely identify and develop FHB-resistant barley germplasm and cultivars.

Comparison between Ultrasound- and Microwave-Assisted Extraction Methods to Determine Phenolic Compounds in Barley (Hordeum vulgare L.).

Barley (Hordeum vulgare L.) is one of the major cereal crops worldwide. It is grown not only to be used as fodder but also for human consumption. Barley grains are a great source of phenolic compounds, which are particularly interesting for their health-promoting antioxidant properties, among other benefits. Two extraction methods, namely ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE), have been optimized and compared by using Box-Behnken design (BBD) to determine both the antioxidant power and the phenolic compound levels of the extracts. Three variables have been assessed based on these designs: solvent composition (% MeOH in water), temperature (°C), and sample-to-solvent ratio (mg sample mL-1 solvent). The solvent composition used and the interaction between the solvent and the temperature were the most significant variables in terms of recovery of phenolic compounds and antioxidant capacity of the extracts. Short extraction times, a high precision level, and good recoveries have been confirmed for both methods. Moreover, they were successfully applied to several samples. Significant differences regarding the level of phenolic compounds and antioxidant power were revealed when analyzing three different barley varieties. Specifically, the amounts of phenolic compounds ranged from 1.08 to 1.81 mg gallic acid equivalent g-1 barley, while their antioxidant capacity ranged from 1.35 to 2.06 mg Trolox equivalent g-1 barley, depending on the barley variety. Finally, MAE was found to be slightly more efficient than UAE, presenting higher levels of phenolic compounds in the extracts.

A New Fluorescence Detection Method for Tryptophan- and Tyrosine-Derived Allelopathic Compounds in Barley and Lupin.

Barley (Hordeum vulgare) is one of the most widely cultivated crops for feedstock and beer production, whereas lupins (Lupinus spp.) are grown as fodder and their seeds are a source of protein. Both species produce the allelopathic alkaloids gramine and hordenine. These plant-specialized metabolites may be of economic interest for crop protection, depending on their tissue distribution. However, in high concentrations they pose a health risk to humans and animals that feed on them. This study was carried out to develop and validate a new method for monitoring these alkaloids and their related metabolites using fluorescence detection. Separation was performed on an HSS T3 column using slightly acidified water-acetonitrile eluents. Calibration plots expressed linearity over the range 0.09-100 pmol/µL for gramine. The accuracy and precision ranged from 97.8 to 123.4%, <7% RSD. The method was successfully applied in a study of the natural range of abundance of gramine, hordenine and their related metabolites, AMI, tryptophan and tyramine, in 22 barley accessions and 10 lupin species. This method provides accurate and highly sensitive chromatographic separation and detection of tryptophan- and tyrosine-derived allelochemicals and is an accessible alternative to LC-MS techniques for routine screening.

Gene expression and metabolite analysis in barley inoculated with net blotch fungus and plant growth-promoting rhizobacteria

Net blotch, caused by the ascomycete Drechslera teres, can compromise barley production. Beneficial bacteria strains are of substantial interest as biological agents for plant protection in agriculture. Belonging to the genus Paraburkholderia, a bacterium, referred to as strain B25, has been identified as protective for barley against net blotch. The strain Paraburkholderia phytofirmans (strain PsJN), which has no effect on the pathogen's growth, has been used as control. In this study, the expression of target genes involved in cell wall-related processes, defense responses, carbohydrate and phenylpropanoid pathways was studied under various conditions (with or without pathogen and/or with or without bacterial strains) at different time-points (0-6-12-48 h). The results show that specific genes were subjected to a circadian regulation and that the expression of most of them increased in barley infected with D. teres and/or bacterized with the strain PsJN. On the contrary, a decreased gene expression was observed in the presence of strain B25. To complement and enrich the gene expression analysis, untargeted metabolomics was carried out on the same samples. The data obtained show an increase in the production of lipid compounds in barley in the presence of the pathogen. In addition, the presence of strain B25 leads to a decrease in the production of defense compounds in this crop. The results contribute to advance the knowledge on the mechanisms occurring at the onset of D. teres infection and in the presence of a biocontrol agent limiting the severity of net blotch in barley.

Exploring natural diversity reveals alleles to enhance antioxidant system in barley under salt stress

Soil salinity stress causes osmotic/ionic imbalances and induces oxidative stress that causes cellular structure damage, perturbs metabolism, antioxidant system (comprising enzymatic and non-enzymatic components) and hence inhibits plant growth performance. In this study, we used genome-wide association scan (GWAS) in 174 diverse spring barley accessions which were exposed to salt stress under field conditions at the vegetative stage to uncover the genetic basis of antioxidant components and agronomic traits. High activities of enzymatic and content of non-enzymatic antioxidants were observed under salt stress compared to control conditions. Under salt stress, all the agronomic and yield-related traits were significantly reduced. Six genomic regions were associated with antioxidants and agronomic traits under salt stress conditions which were found to be linked with candidate genes. Several significant associations were physically located inside or near genes which are potentially involved in antioxidants. Two candidate genes at 2H (40,659,364 bp) and 7H (416,743,127 bp) were found to be involved in Dihydroflavonol 4-reductase/flavanone protein and Glyceraldehyde-3-phosphate dehydrogenase, respectively. The allelic variation at SNP of BK_07 at 7H inside the GAPDH gene demonstrates a negative selection of accessions carrying A allele. This allele appears in cultivars with lower activity of enzymatic antioxidants e.g. superoxide dismutase and catalases under salt stress conditions. These accessions are predominantly two-rowed, cultivars, originated from Europe, and carrying photoperiod sensitive alleles. The detected associated molecular markers in this work are considered as an important source for selection of increased amount of antioxidant compounds in barley under stress conditions.

Light and CO2 Modulate the Accumulation and Localization of Phenolic Compounds in Barley Leaves.

Barley (Hordeum vulgare) accumulates phenolic compounds (PhCs), which play a key role in plant defense against environmental stressors as antioxidants or UV screening compounds. The influence of light and atmospheric CO2 concentration ([CO2]) on the accumulation and localization of PhCs in barley leaves was examined for two varieties with different tolerances to oxidative stress. PhC localization was visualized in vivo using fluorescence microscopy. Close relationships were found between fluorescence-determined localization of PhCs in barley leaves and PhC content estimated using liquid chromatography coupled with mass spectroscopy detection. Light intensity had the strongest effect on the accumulation of PhCs, but the total PhC content was similar at elevated [CO2], minimizing the differences between high and low light. PhCs localized preferentially near the surfaces of leaves, but under low light, an increasing allocation of PhCs in deeper mesophyll layers was observed. The PhC profile was significantly different between barley varieties. The relatively tolerant variety accumulated significantly more hydroxycinnamic acids, indicating that these PhCs may play a more prominent role in oxidative stress prevention. Our research presents novel evidence that [CO2] modulates the accumulation of PhCs in barley leaves. Mesophyll cells, rather than epidermal cells, were most responsive to environmental stimuli in terms of PhC accumulation.

Prediction of bioactive compounds in barley by near-infrared reflectance spectroscopy (NIRS)

Barley grains contain a variable amount of biologically active compounds such as non-starch polysaccharides and phenol compounds. These compounds are important in nutrition due to their significant health benefits and technological role in food. We developed predictive models for β-glucans (BG), arabinoxylans (AX), bound phenols (BP), free phenols (FP), and anthocyanins (AN) based on near-infrared spectroscopy (NIRS) using two different NIRS instruments with different spectral range and spectral steps. Regressions of modified partial least squares (MPLS) and several combinations of scattering correction and derivative treatments were tested. The optimal calibration models generated high coefficients of determination for BG and BP, but not for AN content. The instrument with the highest resolution only gave better results for BG prediction models, and the addition of the visible range did not prove to be ostensibly advantageous to the determination of any of the active compounds of study, not even in the case of AN analysis.

Profiling the volatile carbonyl compounds of barley and malt samples using a low-pressure assisted extraction system

In this work, an analytical methodology for the analysis of volatile carbonyl compounds in barley and malt samples is presented. A simple low-pressure extraction system for volatile compounds was developed. This analytical tool enabled the extraction of volatile compounds directly from barley or malt solid samples (15 min extraction, 10.0 g sample) to an acceptor derivatizing liquid solution, thereafter analyzed by HPLC-DAD-ESI-MS/MS. The low-pressure conditions, pressure of 20 ± 2 in. Hg vac. (33.7 ± 3.7 kPa), enabled to increase the efficiency of the extraction process of some volatile compounds up to 3-fold comparing to normal conditions. Also, no heating procedures were applied, avoiding possible sample degradation and adulteration. Barley and different malt samples, namely pilsner, caramel, chocolate and black, were evaluated. Relevant differences were observed in the volatile carbonyl compounds profile between the samples analyzed. Specialty malts showed richer volatile profiles comparing to barley and pilsner malt samples. Some marker compounds, such as hydroxyacetone and furfural responsible for caramellic, burnt and bready flavours, could be assigned for the most intensely roasted malt samples. In comparison, 2- methylbutanal and 3-methylbutanal were characteristic for caramel malt. The results herein obtained showed that this analytical methodology could be a valuable analytical tool in the characterization, as well as in the quality control of these important raw materials during the malting and roasting processes.

Identification of the gene network modules highly associated with the synthesis of phenolics compounds in barley by transcriptome and metabolome analysis

Phenolic compounds in barley grains have an important influence on beer flavor and stability. Drought condition enhances the content of phenolics in barley grains, leading to reduced malt quality. In this study, two barley genotypes, XZ20 and XZ25 with different total phenolics content were used to investigate the effect of drought on phenolic compounds during grain developing stage. Totally, 118 phenolic metabolites were affected by drought stress. A weighted gene co-expression network analysis (WGCNA) of 17,424 highly expressed genes uncovered black (two hub genes belonged to UGT family) and turquoise modules (three hub genes belonged to phenolics pathway) that are significantly associated with the variation of phenolics. All these results reveal the changes of phenolic metabolites during grain development and provide a new insight into the regulation network of phenolic compounds under drought stress.

Effects on Lipid Oxidation and Bioactive Properties of Rainbow Trout Fillets Fed with Barley

ABSTRACTBarley concentrations ranging from 0% to 32% were incorporated into rainbow trout (Oncorhynchus mykiss) diets. The effect of barley concentration on lipid peroxidation and antioxidant activity of fish fillets were analyzed. Results showed that the inclusion of barley in rainbow trout diets had an inhibitory effect on lipid oxidation, probably associated with certain bioactive compounds in barley that could interact with scavenging and reducing metabolites involved in lipid oxidation. Concentrations up to 8% of barley produced fish fillets with high antioxidant activity and higher levels of alpha-tocopherol.

Arabidopsis thaliana Immunity-Related Compounds Modulate Disease Susceptibility in Barley

Plants are exposed to numerous pathogens and fend off many of these with different phytohormone signalling pathways. Much is known about defence signalling in the dicotyledonous model plant Arabidopsisthaliana, but it is unclear to which extent knowledge from model systems can be transferred to monocotyledonous plants, including cereal crops. Here, we investigated the defence-inducing potential of Arabidopsis resistance-inducing compounds in the cereal crop barley. Salicylic acid (SA), folic acid (Fol), and azelaic acid (AzA), each inducing defence against (hemi-)biotrophic pathogens in Arabidopsis, were applied to barley leaves and the treated and systemic leaves were subsequently inoculated with Xanthomonastranslucens pv. cerealis (Xtc), Blumeria graminis f. sp. hordei (powdery mildew, Bgh), or Pyrenophora teres. Fol and SA reduced Bgh propagation locally and/or systemically, whereas Fol enhanced Xtc growth in barley. AzA reduced Bgh propagation systemically and enhanced Xtc growth locally. Neither SA, Fol, nor AzA influenced lesion sizes caused by the necrotrophic fungus P. teres, suggesting that the tested compounds exclusively affected growth of (hemi-)biotrophic pathogens in barley. In addition to SA, Fol and AzA might thus act as resistance-inducing compounds in barley against Bgh, although adverse effects on the growth of pathogenic bacteria, such as Xtc, are possible.

Bioconcentration factors and plant–water partition coefficients of munitions compounds in barley

Plants growing in the soils at military ranges and surrounding locations are exposed, and potentially able to uptake, munitions compounds (MCs). The extent to which a compound is transferred from the environment into organisms such as plants, referred to as bioconcentration, is conventionally measured through uptake experiments with field/synthetic soils. Multiple components/phases that vary among different soil types and affect the bioavailability of the MC, however, hinder the ability to separate the effects of soil characteristics from the MC chemical properties on the resulting plant bioconcentration. To circumvent the problem, this work presents a protocol to measure steady state bioconcentration factors (BCFs) for MCs in barley (Hordeum vulgare L.) using inert laboratory sand rather than field/synthetic soils. Three MCs: 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), and 2,4-dinitroanisole (2,4-DNAN), and two munition–like compounds (MLCs): 4-nitroanisole (4-NAN) and 2-methoxy-5-nitropyridine (2-M-5-NPYNE) were evaluated. Approximately constant plant biomass and exposure concentrations were achieved within a one–month period that produced steady state log BCF values: 0.62 ± 0.02, 0.70 ± 0.03, 1.30 ± 0.06, 0.52 ± 0.03, and 0.40 ± 0.05 L kgplant dwt−1 for TNT, 2,4-DNT, 2,4-DNAN, 4-NAN, and 2-M-5-NPYNE, respectively. Furthermore, results suggest that the upper–bounds of the BCFs can be estimated within an order of magnitude by measuring the partitioning of the compounds between barley biomass and water. This highlights the importance of partition equilibrium as a mechanism for the uptake of MCs and MLCs by barley from interstitial water. The results from this work provide chemically meaningful data for prediction models able to estimate the bioconcentration of these contaminants in plants.

Inheritance analysis and mapping of quantitative trait loci (QTL) controlling individual anthocyanin compounds in purple barley (Hordeum vulgare L.) grains.

Anthocyanin-rich barley can have great potential in promoting human health and in developing nutraceuticals and functional foods. As different anthocyanin compounds have different antioxidant activities, breeding cultivars with pre-designed anthocyanin compositions could be highly desirable. Working toward this possibility, we assessed and reported for the first time the genetic control of individual anthocyanin compounds in barley. Of the ten anthocyanins assessed, two, peonidin-3-glucoside (P3G) and cyanidin-3-glucoside (C3G), were major components in the purple pericarp barley genotype RUSSIA68. Quantitative trait locus (QTL) mapping showed that both anthocyanin compounds were the interactive products of two loci, one located on chromosome arm 2HL and the other on 7HS. However, the two different anthocyanin components seem to be controlled by different interactions between the two loci. The effects of the 7HS locus on P3G and C3G were difficult to detect without removing the effect of the 2HL locus. At least one copy of the 2HL alleles from the purple pericarp parent was required for the synthesis of P3G. This does not seem to be the case for the production of C3G which was produced in each of all the different allele combinations between the two loci. Typical maternal effect was also observed in the inheritance of purple pericarp grains in barley. The varied values of different compounds, coupled with their different genetic controls, highlight the need for targeting individual anthocyanins in crop breeding and food processing.

Breakdown, uptake and losses of human urine chemical compounds in barley (Hordeum vulgare) and soybean (Glycine max) agricultural plots

Due to the increasing global demand of food and fibers, a comprehensive analysis was conducted to assess: (1) if application of human urine to agricultural soil provides enough nutrient to satisfy the crop demand for primary and secondary nutrients; and (2) if breakdown products affect the soil and water quality near-surface and in the aquifer. A biogeochemical reaction network of urine decomposition tested earlier and extended here to include also the N cycle, was integrated in a computational solver describing a soil profile 10 m deep. Barley (Hordeum vulgare) and soybean (Glycine max) were used as test crops in West Wyalong and Moree, New South Wales, Australia. Soil properties, daily precipitation, and evapotranspiration at both locations were used as environmental and boundary conditions. After exploring various scenarios of urine application amount per surface area, frequency, and timing, uptake of primary and secondary nutrients was found to meet the crop demand nearly in full for 2 L/m2 amendment of undiluted urine. Uptake increased nearly linearly with increasing application, but the partitioning between uptake, aqueous, protected, and gaseous phases was found to be nonlinear. Net C and N gas emissions from urine decomposition did not bring about particularly high values, which were in line with fluxes from contemporary agricultural practices. With the pH stabilizing at about 5.5 and the salinity increasing by less than 2 mM in the top soil, it was inferred that soil and water qualities were not substantially altered even after 20 years of repeated urine applications.

Determination of Phenolic Content in Different Barley Varieties and Corresponding Malts by Liquid Chromatography-diode Array Detection-Electrospray Ionization Tandem Mass Spectrometry.

A simple and reliable method for the simultaneous determination of nine phenolic compounds in barley and malted barley was established, using liquid chromatography-diode array detection-electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI-MS/MS). The phenolic compounds can be easily detected with both systems, despite significant differences in sensitivity. Concentrations approximately 180-fold lower could be achieved by mass spectrometry analysis compared to diode array detection, especially for the flavan-3-ols (+)-catechin and (−)-epicatechin, which have poor absorptivity in the UV region. Malt samples were characterized by higher phenolic content comparing to corresponding barley varieties, revealing a significant increase of the levels of (+)-catechin and (−)-epicatechin during the malting process. Moreover, the industrial malting is responsible for modification on the phenolic profile from barley to malt, namely on the synthesis or release of sinapinic acid and epicatechin. Accordingly, the selection of the malting parameters, as well as the barley variety plays an important role when considering the quality and antioxidant stability of beer.

A powerful methodological approach combining headspace solid phase microextraction, mass spectrometry and multivariate analysis for profiling the volatile metabolomic pattern of beer starting raw materials

The volatile metabolomic patterns from different raw materials commonly used in beer production, namely barley, corn and hop-derived products – such as hop pellets, hop essential oil from Saaz variety and tetra-hydro isomerized hop extract (tetra hop), were established using a suitable analytical procedure based on dynamic headspace solid-phase microextraction (HS-SPME) followed by thermal desorption gas chromatography–quadrupole mass spectrometry detection (GC–qMS). Some SPME extraction parameters were optimized. The best results, in terms of maximum signal recorded and number of isolated metabolites, were obtained with a 50/30μm DVB/CAR/PDMS coating fiber at 40°C for 30min. A set of 152 volatile metabolites comprising ketones (27), sesquiterpenes (26), monoterpenes (19), aliphatic esters (19), higher alcohols (15), aldehydes (11), furan compounds (11), aliphatic fatty acids (9), aliphatic hydrocarbons (8), sulphur compounds (5) and nitrogen compounds (2) were positively identified. Each raw material showed a specific volatile metabolomic profile. Monoterpenes in hop essential oil and corn, sesquiterpenes in hop pellets, ketones in tetra hop and aldehydes and sulphur compounds in barley were the predominant chemical families in the targeted beer raw materials. β-Myrcene was the most dominant volatile metabolite in hop essential oil, hop pellets and corn samples while, in barley, the predominant volatile metabolites were dimethyl sulphide and 3-methylbutanal and, in tetra hop, 6-methyl-2-pentanone and 4-methyl-2-pentanone. Principal component analysis (PCA) showed natural sample grouping among beer raw materials.

Parâmetros climáticos e variação de compostos fenólicos em cevada

Objetivou-se quantificar os compostos fenólicos em extrato hidroetanólico de grãos das cultivares de cevada ('BRS Lagoa' e 'MN 743') em dois anos consecutivos de cultivo (2005 e 2006), avaliando a influência dos fatores climáticos nesse conteúdo. Os compostos fenólicos totais foram quantificados pelo método de Folin-Ciocalteau e os teores de rutina e ácidos cafeico e ferúlico por CLAE em fase reversa. O conteúdo de compostos fenólicos totais variou de 0,97 a 1,59 mg AG g-1 de cevada e os fatores climáticos durante o período de plantio e colheita influenciaram no conteúdo. Foram identificados e quantificados nessas cultivares rutina, ácido cafeico e ácido ferúlico. A avaliação dos fatores climáticos no conteúdo de compostos fenólicos em cevada é de grande interesse, visando a sua importância nutricional e recomendação de cultivares com conteúdos expressivos de compostos bioativos.

Qualitative and quantitative analysis of the major phenolic compounds as antioxidants in barley and flaxseed hulls using HPLC/MS/MS

Both qualitative and quantitative analyses of the major phenolic compounds in barley and flaxseed hulls were conducted using reverse phase high-performance liquid chromatography coupled with photodiode array detection and quadrupole time-of-flight mass spectrometry. Ferulic acid, p-coumaric acid, vanillic acid and vanillin were identified and quantified in four barley hull samples. Four ferulate dehydrodimers were also detected. The phenolic compounds of flaxseed hull were distinct from those of barley hull. Three flaxseed hull samples varied significantly (P < 0.05) in their contents of secoisolariciresinol diglucoside (16.38-33.92 g kg(-1) ), coumaric acid glucoside (35.68-49.22 g kg(-1) ) and ferulic acid glucoside (5.07-15.23 g kg(-1) ). The phytochemical profiles of co-extracts featured the major phenolic compounds from both barley and flaxseed hulls. The total phenolic content and 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity varied significantly (P < 0.05) among different varieties of flaxseed and barley hulls. As agricultural by-products, barley and flaxseed hulls may be utilised as potential sources of functional food ingredients through extraction and concentration of the phytochemicals identified above.

Air classification of barley flours to produce phenolic enriched ingredients: Comparative study among MEKC-UV, RP-HPLC-DAD-MS and spectrophotometric determinations

The aim of this paper was to use the air classification technology to produce barley flours enriched in phenolic compounds and to obtain naturally enriched ingredients for pasta and bakery industry. Phenolic compounds in barley have been described in literature using different methodologies that are not easily comparable. This paper describes a comparative study between different separative and spectrophotometric methods to determine free and bound phenolic compounds in barley flours and their air classified fractions from three different cultivars grown in the same experimental field. To this end, reversed phase-high performance liquid chromatography, micellar electrokinetic chromatography, and spectrophotometric determinations were applied. The barley phenolic compounds analyzed included mainly catechins and proanthocyanidins as free phenols, and hydroxycinnamic acids and their derivatives as bound phenols. The enriched fractions obtained by air classification showed an increase of free flavan-3-ols of 157–173% compared to whole flour. The same fractions also reported larger concentration of bound phenolic compounds (160–236%) with respect to whole flours. Air classification results a good technique to enrich the flours and to utilize the barley co-products.