Compositional equivalence of barleys differing only in low- and normal-phytate levels

Recent breeding advances have led to the development of several barley lines and cultivars with significant reductions (50% or greater) in phytate levels. Low-phytate (LP) grain is distinguished by containing not only a reduced level of phytate P but also an increased level of inorganic P, resulting in greater bioavailability of P and mineral cations in animal diets. It is important to determine whether other nutritional characteristics are altered by breeding for the low-phytate trait. This study was designed to investigate if breeding for reduced phytate content in barleys had any effect on the contents of other attributes measured by comparing mean and range values of the levels of protein, oil, ash, total carbohydrate, starch, and β-glucan, fatty acid composition, and levels of tocopherols and tocotrienols between five LP and five normal-phytate barleys grown in three Idaho locations. Results show that only the phytate level in the LP group was substantially lower than that of the normal-phytate group and that all other attributes measured or calculated were substantially equivalent between the two groups of barleys. Therefore, the phytate level had little effect on the levels of protein, oil, ash, total carbohydrate, starch, and β-glucan, fatty acid composition, and levels of tocopherols and tocotrienols in barley seeds.     

Wet Processing of Barley Grains into Concentrates of Proteins, β‐Glucan,and Starch

An improved wet method was developed to process barley into fractions concentrated in protein, (1‐3)(1‐4)‐β‐d ‐glucan (BG), starch, or other carbohydrates (CHO). Alkaline concentration, solvent to barley flour ratio (SFR), and extraction temperature were evaluated for their effects on concentration and recovery of protein, BG, starch, oil, ash, and other CHO in each fraction type. Results show that the three parameters and their interactions all had significant effects, resulting in varying nutrient concentrations and recovery rates in each type of fractions. For protein fractions, protein content varied from 37.7 to 75.2%, protein recovery from 8.5 to 75.7%, and increasing alkaline concentration and SFR improved nutrient recovery. For BG fractions, BG content ranged from 21.5 to 87.0%, BG recovery from 28.6 to 78.0%, and increasing alkaline concentration decreased BG content but increased its recovery significantly. For starch fractions, starch content varied from 76.9 to 93.9%, starch recovery from 33.6 to 63.9%, and all parameters had little effect on the nutrient concentrations, but alkaline concentration and SFR improved recovery of starch, other CHO, and mass. Overall, the improved wet method was effective in concentrating the major nutrients from barley into their respective fractions, but process optimization through manipulating the three parameters is necessary to achieve a maximum concentration or recovery rate of a nutrient of interest in a specific fraction.     

Molecular Weight Distribution and (1→3)(1→4)-β-d-Glucan Content of Consecutive Extracts of Various Oat and Barley Cultivars

The content and molecular weight (MW) of β-glucan in extracts from a selection of oat and barley cultivars were compared using flow-injection analysis and high-performance size-exclusion chromatography. From 60 to 75% of the β-glucan was extracted from oat and waxy barley by hot water (90°C) containing heat-stable α-amylase, whereas just 50–55% was extracted from nonwaxy barley. Consecutive extractions with hot water and dimethylsulfoxide (DMSO) extracted 65% (nonwaxy barley) or 75–80% (oat and waxy barley) of the total β-glucan. An extraction with sodium hydroxide and sodium borohydride (NaOH/NaBH₄) increased the percentage of β-glucan extracted to 86–100% but decreased the MW. The MW of β-glucan in the oat cultivars selected was significantly higher than those in the barley cultivars. The β-glucan extracted from the nonwaxy barley cultivars showed significantly higher peak MW than that from the waxy barley cultivars.     

Isolation and Characterization of High‐Purity Starch Isolates from Regular,Waxy, and High‐Amylose Hulless Barley Grains

Recovering starch from barley is problematic typically due to interference from β‐glucan (the soluble fiber component), which becomes highly viscous in aqueous solution. Dry fractionation techniques tend to be inefficient and often result in low yields. Recently, a protocol was developed in our laboratory for recovering β‐glucan from barley in which sieving whole barley flour in a semiaqueous (50% ethanol) medium allowed separation of the starch and fiber fractions without activating the viscosity of the β‐glucan. In this report, we investigate an aqueous method which further purifies the crude starch component recovered from this process. Six hulless barley (HB) cultivars representing two each of waxy, regular, and high‐amylose cultivars were fractionated into primarily starch, fiber, and protein components. Starch isolates primarily had large granules with high purity (>98%) and yield range was 22–39% (flour dry weight basis). More importantly, the β‐glucan extraction efficiency was 77–90%, meaning that it was well separated from the starch component during processing. Physicochemical evaluation of the starch isolates, which were mainly composed of large granules, showed properties that are typical of the barley genotypes.     

The Potential of Hull-less Barley

Hull-less barley (HB) has been investigated in many countries for use in feed, food, and industry since the publication of the last review in 1986. Literature published since 1990 on various aspects of HB utilization, other than in monogastric feeds, has been reviewed. Several HB cultivars containing low or β-glucan, low or high extract viscosity, and waxy (0–5% amylose) or normal starch are now available. Interest in HB utilization in the food industry developed largely due to its high β-glucan content, particularly in the waxy cultivars. β-Glucan is a major component of soluble fiber implicated in hypocholesterolemia, hypoglycemia, and in reducing incidence of chemically induced colon cancer in experimental animals. However, large-scale clinical trials using human subjects are needed to corroborate these effects. The zero amylose HB starch had low syneresis or a high freeze-thaw stability suitable for use in frozen foods. Single- or double-modified waxy HB starch may replace corn starch in some food applications, and cationized HB starch can replace corn and potato starches in the pulp and paper industry. HB may be milled using conventional wheat milling equipment to yield bran and flour for multiple food uses. Hull-less barley may also be used as a feed stock for fuel alcohol production, for the preparation of food malt with low or high enzyme activities, and for brewer's and distiller's malts.     

Composition of Oat Bran and Flour Prepared by Three Different Mechanisms of Dry Milling

Three mechanisms of oat milling were tested for laboratory-scale oat bran production. Oat bran consistent with AACC definition and commercially obtained product was generated with either roller-milling or impact-milling of groats, followed by sieving to retain larger particles. These bran preparations were enriched ≈1.7-fold in β-glucan and ash, 1.4-fold in protein, and 1.1-fold in lipid. Bran finishing made further enrichments in protein, β-glucan, and ash. Tempering oat (to 12% moisture for 20 min) improved bran yield from roller-milling nearly two-fold but had little effect on bran composition. Bran yield from the impact-type mill was significantly affected by grinding screen size. Oat bran obtained from a pearling mill was only slightly enriched in β-glucan and protein, but it was more heavily enriched in ash and oil than brans from roller or impact mills. The pearling mill isolated the outer layers of the groat directly, but because of its low β-glucan composition it did not meet the AACC definition of oat bran, indicating a relatively uniform distribution of β-glucan in the groat.     

青海黑青稞营养及活性成分分析与评价

为明确青海不同品种黑青稞的营养及化学成分含量,筛选优异种质资源,本研究开展了12种黑青稞营养及化学成分分析与评价。结果表明,参试黑青稞蛋白、总淀粉、直链淀粉、粗脂肪、粗纤维、灰分、β-葡聚糖含量在部分品种间存在显著差异(P<0.05),黑青稞具有较高含量的蛋白质(12.19%~14.07%)、纤维(2.13%~3.64%)、直链淀粉(18.96%~25.94%)和β-葡聚糖(3.91%~7.50%);参试黑青稞中Ca、K、Zn含量存在品种间显著差异(P<0.05),其余测定的矿物质含量存在部分品种间显著差异(P<0.05),其中K(581.42 mg·100g^-1)、Mg(171.90 mg·100g^-1)、Ca(90.28 mg·100g^-1)、Na(17.33 mg·100g^-1)含量较高;参试黑青稞蛋白中总必需氨基酸含量平均值为319.90 mg·g^-1(接近WHO/FAO推荐值360 mg·g^-1),第一限制性氨基酸为赖氨酸,第二限制性氨基酸为甲硫氨酸和胱氨酸,第三限制性氨基酸为苏氨酸;参试部分黑青稞品种的总酚、游离酚、结合酚、总黄酮、游离黄酮、结合黄酮及花色苷含量存在显著差异(P<0.05);主成分筛选出950、Z536、Z533黑青稞综合品质较优,聚类分析将12个黑青稞品种分为4类,第1类蛋白质、多酚、黄酮、β-葡聚糖含量较高;第2类花色苷、氨基酸含量较高;第3类纤维含量较高;第4类淀粉含量较高。本研究结果为黑青稞营养功能品质评价及加工利用奠定了基础,也为特异青稞资源的筛选提供了参考。     

Kernel Properties and Pasta-Making Quality of Five European Spelt Wheat (Triticum spelta L.) Cultivars

The kernel characteristics and composition, milling performance, protein quality, and alveograph parameters of five spelt cultivars grown in European countries were determined in relation of their utilization in pasta products. Long pasta was manufactured and chemically characterized, and its quality was assessed by sensory and chemical tests. Protein and fat contents were high in the grains (15.7 and 4.4% db, mean value, respectively). Total fiber varied from 10.5 to 14.9% db. The average β-glucan content was 1.2% db. The milling performance as determined by yield, damaged starch, ash, and particle-size distribution in the flour was uniform among the five cultivars. The results of the SDS sedimentation and gluten index tests indicated that spelt gluten strength was low, and this was confirmed by the alveograph test. Sensory and chemical evaluations of the pastas, however, indicated that spelt is suitable for obtaining good-quality pasta. The combination of the high protein content and the high-temperature drying cycle adopted in pasta production could be responsible for these good results.     

Structure and Physicochemical Properties of Starches from Sieve Fractions of Oat Flour Compared with Whole and Pin-Milled Flour

One oat cultivar grown in Idaho (three field sites) was pin-milled and separated by sieving to investigate whether starch from oat bran differs from the remainder of kernel. Ground oat particles were classified into three sieve fractions: 300–850 μm, 150–300 μm and <150 μm). β-Glucan content in sieve fractions was analyzed and starch was extracted from kernels without milling and from kernels of each sieve fraction. β-Glucan contents of 300–850, 150–300, and <150 μm sieve fractions were 4.2, 2.3, and 0.8%, respectively. Therefore, starch in bran (300–850 μm sieve fraction) and endosperm (<150 μm sieve fraction) were separated. Starch isolated from entire kernels had significantly higher apparent and absolute amylose content than starch from the 300–850 μm sieve fraction. Starch from different sieve fractions was not significantly different in the apparent amylose, absolute amylose, amylopectin molecular weight, gyration radii, starch gelatinization, and amylose-lipid complex thermal transition temperatures. Starch from the 150–300 μm sieve fraction had significantly lower peak, final, and setback viscosity compared with the starch isolated from the 300–850 μm and <150 μm sieve fractions. Starch removed from the oat bran fraction during β-glucan enrichment may have different applications compared with starch obtained from other kernel compartments. Because pin-milling decreased apparent amylose content and shortened amylopectin branch chains, its potential to alter starch structure should be considered.     

Quality of Flours from Waxy and Nonwaxy Barley for Production of Baked Products

One nonwaxy (covered) and two waxy (hull-less) barleys, whole grain and commercially abraded, were milled to break flour, reduction flour, and the bran fraction with a roller mill under optimized conditions. The flour yield range was 55.3–61.8% in whole grain and increased by 9–11% by abrasion before milling. Break flours contained the highest starch content (≤85.8%) independent of type of barley and abrasion level. Reduction flours contained less starch, but more protein, ash, free lipids, and total β-glucans than break flours. The bran fraction contained the highest content of ash, free lipids, protein, and total β-glucans but the lowest content of starch. Break flours milled from whole grain contained 82–91% particles <106 μm, and reduction flours contained ≈80% particles <106 μm. Abrasion significantly increased the amount of particles <38 μm in break and reduction flours in both types of barley. Viscosity of hot paste prepared with barley flour or bran at 8% concentration was strongly affected by barley type and abrasion level. In cv. Waxbar, the viscosity in bran fractions increased from 428 to 1,770 BU, and in break flours viscosity increased from 408 to 725 BU due to abrasion. Sugar snap cookies made from nonwaxy barley had larger diameter than cookies prepared from waxy barley. Cookies made from break flours were larger than those made from reduction flours, independent of type of barley. Quick bread baked from nonwaxy barley had a loaf volume similar to that of wheat bread, whereas waxy barley bread had a smaller loaf volume. Replacement of 20% of wheat flour by both waxy and nonwaxy barley flour or bran did not significantly affect the loaf volume but did decrease the hardness of quick bread crumb.     

Composition,Microstructure, Water Imbibition,and Thermal Properties of Abraded Barley

Barley, nonwaxy hull (cvs. Crystal and Meltan) and waxy hull-less (cvs. Merlin and Waxbar), was abraded at 10, 20, and 40% of kernel weight on a laboratory scale and commercially abraded at two levels: fine and coarse. In 40% abraded kernels of Crystal, protein, ash, and free lipids contents decreased by 1.6, 1.4, and 1.4%, respectively, and starch and β-glucans contents increased by 16 and 1.2%, respectively, compared to nonabraded kernels. Merlin showed smaller changes in the levels of these components, except for proteins. Changes in starch and protein in laboratory abraded barley were used to estimate the level of barley abrasion on a commercial scale. Scanning electron microscope pictures revealed that in nonwaxy barley at 10% abrasion the hull and part of the seed coat were absent, whereas waxy barley lost all of the seed coat and most of the aleurone layer. Maximum water imbibition of 40% abraded waxy barley was reached after 5 hr of soaking, whereas nonwaxy barley needed 8 hr to level off. Nonwaxy barley kernels at 20% abrasion and cooked for 10 min required 52 N to compress to 50% thickness, whereas waxy barley needed only 28 N. Changes in chemical composition and microstructure due to abrasion had a strong effect on the thermal properties of kernels during cooking. The extent to which barley starch was gelatinized during cooking was evaluated by differential scanning calorimetry. Crystal and Merlin showed significant decreases in enthalpy value for 40% compared to 10% abraded barley. These results indicate that when a large portion of the outer layer of barley is removed, water and heat penetrate more quickly into kernels during cooking, causing more starch to be gelatinized. The results obtained in this study indicate that changes in composition and microstructure due to abrasion affect the rate of water imbibition, hardness of cooked kernels, and enthalpy value of starch. Composition and properties of laboratory abraded barley could be used to predict the level of abrasion and properties of barley abraded on a commercial scale within the same cultivar.     

生态条件对大麦产量及β-葡聚糖含量的影响

为明确不同生态条件下大麦籽粒产量及β-葡聚糖含量的环境效应,选取了11个不同的大麦品种,在全国6个生态条件有差异的试点种植。结果表明,各试点间大麦籽粒产量差异显著,襄樊试点平均产量最高;苏啤3号大麦在6个试点的平均产量最高,达5391.7kg/hm2,与其他品种差异显著。各试点及各品种间,大麦籽粒β-葡聚糖含量差异也达到显著水平。G231M004M大麦在6个试点β-葡聚糖含量的平均值显著高于其他品种;各个大麦品种在保山试点的籽粒β-葡聚糖含量均明显高于其他试点。因此,选取特定品种种植在适宜的生态条件下对调节大麦籽粒产量和β-葡聚糖含量具有积极意义。     

Comparisons of β-Glucan Content of Barley and Oat

The cholesterol-lowering effect of cereal grains has been associated with the soluble fiber component of dietary fiber. β-Glucan is the major soluble fiber component of barley (Hordeum vulgare L.) and oat (Avena sativa L.). Much research has been conducted to determine the β-glucan content of barley and oat genotypes from many different countries. However, genotypes of both crops always were grown in separate experiments, making direct comparisons between the two crops difficult. This study compares in the same experiment the β-glucan content of nine barley and 10 oat genotypes grown at two locations in each of two years (i.e., four environments) in North Dakota. Averaged across genotypes, total β-glucan content of barley and oat groat was similar. Soluble β-glucan content of oat groat was greater than barley, and oat groat had a greater ratio of soluble-to-total β-glucan than barley. The soluble β-glucan content and ratio of soluble to total β-glucan content of the “best” barley genotypes were less than that of oat genotypes with the highest levels of these two traits.     

Effect of Extraction Conditions on Yield,Composition, and Viscosity Stability of Barley β-Glucan Gum

Cereal β-glucan can function as a thickener, but endogenous β-glucanase enzymes of the grain cleave β-glucan, reducing its viscosity. Although different extraction techniques have been developed, the viscosity stability of β-glucan gum has not been reported. The objective of this study was to investigate the effect of extraction treatments on the yield, purity, and viscosity stability of barley β-glucan (BBG) gum. A regular barley cultivar, Condor, and a waxy cultivar blend were extracted at pH 7–10 and 55°C for 0.5 hr. Four extraction conditions were evaluated: 1) extraction at high pH with no additional heat treatment; 2) boiling of extract; 3) prior refluxing of flour with 70% ethanol; and 4) treatment of extract with thermostable α-amylase for purification. Viscosity of extracts was monitored for ≥24 hr at 25°C. The highest β-glucan purities were achieved with a boiled Condor extract at pH 7 (81.3% db, 4.1% yield) and with refluxed waxy barley extracted at pH 8 and treated with α-amylase and (79.3% db, 5.1% yield). Gums extracted without subsequent heat treatment or prior refluxing of flour had high protein (>17%) and starch (>24%) impurities, respectively. The viscosity of gums obtained without heating was unstable. Prior refluxing treatment was not sufficient to stabilize final extracts. Boiling extracts resulted in stable but low viscosity. Reflux followed by purification treatment produced the highest stable viscosity for 0.5% solutions of both Condor (64 mPa sec^-1, pH 7) and waxy (48.8 mPa sec^-1, pH 8) extracts. Stable BBG gum with high viscosity can be obtained using thermal treatments in combination with high pH. The potential use of such gums as thickeners in food systems needs to be assessed.     

Differences in Carbohydrate Composition and Digestion In Vitro of Selected Barley Cultivars as Influenced by Pearling and Cooking

Among common cereals, barley is a low glycemic index food. In an attempt to better understand this character, the nutritional properties of glycemic carbohydrates and dietary fiber concentrations of nine cultivars were evaluated. The cultivars were selected based on botanical variations and commercial value to investigate the impact of pearling and cooking on nutritional properties. Each cultivar was pearled into four fractions ranging from hull removal only to hull, bran, germ, and crease removal. The study showed that botanical class and degree of pearling significantly affect the carbohydrate composition and digestion indices of barley. Waxy starch cultivars had less total starch and more rapidly digestible starch (RDS), rapidly available glucose (RAG), and β‐glucan than the other nonwaxy cultivars. Regardless of the barley type, the less pearled kernels had significantly lower total starch and higher total low molecular weight sugars, insoluble, and total fiber. However, β‐glucan content was fairly comparable in the whole grain and pearled fractions. Cooking had a significant effect on nutritional properties of Celebrity and AC Klinck cultivars. The only consistent significant difference between raw and cooked barley was resistant starch (RS), which increased after cooking regardless of cultivar or fraction. The study showed that barley cultivar and carbohydrate composition significantly affected starch digestion with some cultivar fractions holding a promise for the development of low glycemic index foods.     

High‐Starch and High‐β‐Glucan Barley Fractions Milled with Experimental Mills

This study focused on the performance of two hulless barley cultivars (Doyce and Merlin) and one commercial husked (hulled) sample using experimental milling. The purpose was to use experimental milling as a preliminary indicator of the milled streams with potential use for fuel ethanol production and fractions that could be used in food products. Experimental mills designed for flour production evaluation from wheat were Chopin CD1 Auto, Quadrumat Sr, Buhler, and an experimental Ross roller mill walking flow. Results indicate that the shorts had the highest levels of β‐glucan from all the mills. However, the β‐glucan content in the break flours was highest with the roller mill walking flow and the Chopin CD1 for the hulless cultivars. The lowest β‐glucan content in the break flour was found with the Buhler for Doyce. Break flour and, to a slightly lesser extent, reduction flour from all cultivars tested on all mills contained the highest starch content (up to 83%) and are therefore most appropriate for use as feedstock for fuel ethanol production. Conversely, bran and shorts from all cultivars and mills were lowest in starch (as low as 25%), making them ideal as low‐starch food ingredients.     

Enzyme-Assisted Wet Separation of Starch from Other Seed Components of Hull-less Barley

A multiple enzyme cocktail containing cellulase, endo-(1→3), (1→4)-β-d -glucanase and xylanase was used in wet separation of starch, protein, β-glucan, bran, and tailings from four hull-less barleys (HB): SB94794 (0% amylose), CDC Candle (5% amylose), CDC Dawn (24% amylose), and SB550831 (40% amylose). Compared to a conventional procedure, the enzyme-assisted wet extraction reduced slurry viscosity by 50–99%, the amount of water and ethanol used in screening and β-glucan precipitation by 30–60%, and screening time by 20–80%. The enzyme-assisted extraction reduced starch contents and yields of tailings and bran fractions, resulting in a 10% increase in average starch extraction efficiency. However, β-glucan yield was reduced in the enzyme-assisted extraction, particularly in high-viscosity HB. The physicochemical properties of isolated starches were not affected by the enzyme-assisted extraction.     

Properties and Composition of Turkish Flat Bread (Bazlama) Supplemented with Barley Flour and Wheat Bran

In this study, effects of increasing levels of wheat bran and barley flour on dough properties and bazlama quality were investigated. Bazlama is a flat bread commonly consumed in Turkey. Flours of wheat cultivars Gün and Gerek, flour of barley cultivar Tokak, and Gerek bran mixture were used. Part of the wheat flours were replaced with barley flour at 10, 20, 30, and 40% levels and Gerek bran mixture at 5, 10, 15, and 20% levels. Farinogram properties of mixtures were determined. Bazlama samples were subjected to sensory analysis for external appearance, shape and symmetry, crust color, crumb color and structure, mouthfeel, taste and aroma. Increasing levels of bran and barley flour caused decreases in all sensory properties. The deteriorative effect of barley flour on bazlama properties was generally more obvious when compared to bran supplementation. However, all bazlama samples were considered acceptable. Penetrometer values of bazlama samples showed that increasing levels of barley flour created significantly softer bazlama. However, in bran-supplemented bazlama samples, effect of bran on softness was found to be insignificant in both cultivars. Bazlama samples supplemented with bran had lower L values and higher a and b values for color when compared to those supplemented with barley flour. In all samples, effect of increasing levels of barley flour on residual β-glucan was found to be insignificant in both cultivars. Acid detergent fiber and neutral detergent fiber values increased with increasing levels of bran, and the changes in both cultivars were similar.     

Relationship of Ethanol Yield to Agronomic and Seed Quality Characteristics of Small Grains

Production of fuel ethanol hinges on the availability of carbohydrate sources, with corn being the crop of choice in most areas. However, in some climatic regions, it is not feasible to grow adequate volumes of corn so other starch sources must be utilized. Here we examined various small grain crops commonly grown in the Northern Great Plains for suitability for ethanol production. Four cultivars each of the hexaploid wheat (Triticum aestivum L.) classes hard red spring (HRS), hard white spring (HWS), soft white spring (SWS), along with durum wheat (Triticum durum L.), and four spring barley (Hordeum vulgare L.) cultivars were grown in replicated plots in two environments in 2006. Agronomic and seed quality traits, along with starch content and ethanol yield over a period of 72 hr were measured on all cultivars. Agronomic yield was highest for the barley cultivars and lowest for HRS and HWS. Seed size was greatest for the durum and barley cultivars. The SWS group had the lowest protein content and the highest starch content. Starch content was highly correlated with final ethanol yield and the SWS group was highest in absolute ethanol yield. However, ethanol yield per hectare was highest for barley, with SWS ranking second, while the HRS and HWS groups had the lowest ethanol yields per hectare. The results indicate that selection for small grain ethanol yield should focus primarily upon agronomic yield at the expense of protein content. Traditional selection for high HRS and HWS milling and baking quality is not consistent with maximal ethanol yield per hectare.     

Effects of Pearling,Grinding Conditions,and Roller Mill Flow on the Yield and Composition of Milled Products from Hull‐less Barley

Two hull‐less barley cultivars, one with waxy starch and the other with high‐amylose starch, were roller‐milled unpearled and after 15% pearling. Flows of varying length, with diverse roll settings and roll surfaces were used to determine effects on the yield, composition, and properties of milled products. Similar trends were noted for the two cultivars. When using a short flow comprising four break passages and a sizing passage, power consumption during grinding was reduced by 10% when roll flute orientation was changed from dull‐to‐dull (D/D) to sharp‐to‐sharp (S/S). Flute orientation had minimal effects on the yield and brightness of flour, but SS grinding gave a higher yield of a fiber‐rich fraction (FRF). FRF yield and composition are of particular interest because FRF has potential as a functional food ingredient due to elevated levels of β‐glucans (BG) and arabinoxylans (AX). When using smooth frosted rolls (SM) for the sizing passage, power consumption increased by several times over using fluted sizing rolls with little advantage for either yield or BG content of FRF. FRF starch damage increased when smooth sizing rolls were used, and water swelling, a measure of water hydration capacity, also increased. Setting break and sizing rolls sharp‐to‐sharp significantly lowered the mean particle size of the FRF fraction, accompanied by moderate declines in FRF BG and AX contents. FRF yield decreased ≤50% when milling flow was lengthened to three sizing passages with intermediate impact passages, with only a moderate accompanying increase in FRF fiber content, regardless of roll conditions. Pearling 15% before milling reduced the yield of FRF by ≈30% while moderately reducing flour yield. Flour brightness was improved by pearling. When barley was pearled, FRF contained higher amounts of BG, but lower amounts of AX, phenolics, ash, and protein.