The Future of Barley by mirit35

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									                                                                                                                    cfw report




                                                The Future of Barley

   Epidemiologic studies report that diets rich in whole grains may         The workshop ended with a presentation by Francis Webster on the
protect against hypertension, stroke, cardiovascular disease, and type      status of the barley beta-glucan health claim.
II diabetes. Grains containing high amounts of soluble fiber, such             Barley contains many nutrients, including dietary fiber, antioxi-
as oats or barley, are more effective in lowering blood cholesterol in      dants, vitamins, minerals (calcium, magnesium, potassium, phospho-
animals and humans than are grains containing predominantly insol-          rus), sphingolipids, and unsaturated fatty acids. This diverse com-
uble fibers, such as wheat or rice. On the basis of epidemiologic           position allows barley products to have a myriad of beneficial and
and clinical study results that suggest oats are effective in lowering      appealing characteristics. A number of issues where highlighted dur-
blood cholesterol levels, the U.S. Food and Drug Administration             ing the question-and-answer period following the presentations and
(2001) has allowed a health claim for oats and soluble fibers from          are summarized briefly here.
oats. In addition, whole-grain consumption is emphasized as part of a
healthy diet in the new USDA Food Guide Pyramid (2005). Although            Issues Surrounding Gaps in Basic Science
at least three servings of whole grains per day are recommended,               1. What are the specific mechanisms by which barley can im-
on average Americans consume fewer than one serving per day.                      prove insulin sensitivity?
   Barley, similar to oats, contains high amounts of soluble fiber             2. What is the relationship between the morphology of the grain
(beta-glucan), but it is not extensively consumed in the United                   and its digestion? What is the interaction between the mor-
States. To assess the current advances in technology, biological im-              phology of the grain and bacterial fermentation?
pacts, health benefits, and behavioral aspects of barley consump-              3. Is there an effect of fermentation products (e.g., acetate) on
tion, a workshop on “The Future of Barley” was conducted on May                   adipose metabolism?
17, 2005, in Minneapolis, MN, prior to Whole Grains 2005: A Global
Summit on Whole Grains, Functional Components and Health. The               Connecting Basic Observations with Human Studies Using
workshop began with a comprehensive history of barley cultiva-              Whole Grains
tion and human consumption presented by Walter Newman.                        1. A better understanding of the underlying mechanisms of the
   Barley lends itself to the development of multiple varieties with             health benefits of diets high in soluble fiber from barley is
a range of characteristics. David Topping opened the technology                  needed. Mechanisms of interest include 1) regulation of fatty
session with a discussion of the production of high-amylose bar-                 acid oxidation; 2) regulation of glucose, insulin metabolism
ley varieties, which are a good source of resistant starch and beta-             and sensitivity; and 3) potential regulation of short-term sati-
glucan. Lars Munck described the use of infrared spectroscopy, math-             ety. This mechanism should be targeted for further research
ematical modeling, and chemometrics to classify barley varieties.                in animals and future research in humans.
He indicated there are three general categories: high lysine, high
beta-glucan, and low starch. Robert Kratochvil discussed hulless              2. Although efforts for the health claim are moving forward, it
barley and its uses in the Mid-Atlantic Region of the United States.             is important to improve the acceptability of products contain-
In this region, barley is used to double crop with soybeans, and                 ing barley.
higher starch hulless varieties are being developed for their poten-          3. Challenges include the need for researchers to partner with in-
tial use in ethanol production.                                                  dustry to utilize the information being generated on specific
   Thava Vasanthan spoke on beta-glucan isolation and concentration              functional and nutritional characteristics of barley genotypes
technologies and the impact of different techniques on molecular                 to move them to the marketplace. Barley provides a huge range
structure and functionality. Stefan Sahlström presented informa-                 of properties that make it ideal for a wide variety of success-
tion on the effects of barley beta-glucan and arabinoxylan fractions             ful applications.
on health. David Pascoe discussed data on biologically active com-
pounds found in barley. Barley beta-glucan stimulates the immune            Issues of Public Health and Consumer Acceptance
system, whereas the bran components may reduce inflammation.                   From a public health perspective, several issues were raised:
   Judith Hallfrisch described two controlled-feeding studies in which        1. What kind of educational component is needed to increase
barley flour, flakes, and pearls were incorporated into the diets of             barley consumption? Understanding the levels of whole grain
adults. Beneficial reductions of cardiovascular risk factors were ob-            that are acceptable to the public is key. Perhaps not everyone
served after chronic consumption of diets containing 3 or 6 g of beta-           needs to eat 100% whole grains, and the first goal should be
glucan from barley. Joel Pins presented recent data from a clinical              to encourage any increase in whole-grain consumption.
trial on the beneficial effects on cardiovascular risk factors of chronic
                                                                              2. A second goal should be to increase the value of barley prod-
consumption of foods containing an extracted barley beta-glucan.
                                                                                 ucts to consumers. The future of this work should focus on
Wally Yokoyama described his laboratory’s research with hamsters
                                                                                 understanding consumer acceptance and, at the same time, on
on mechanisms of increased insulin sensitivity in animals fed barley.
                                                                                 ways to make these foods sought after by consumers. How to
Elizabeth Arndt spoke on a specific variety of barley that is high
                                                                                 make barley a preferred choice?
in beta-glucan and protein. Several health benefits were reported.
   Hyunsook Kim reviewed mechanisms by which soluble fiber can                3. The benefits of increasing fiber content to reduce total food
increase satiety and described the acute effect of barley beta-glu-              consumption and the satiating effect of high-fiber foods, in-
can in a meal on postmeal satiety. Nancy Ames presented the physio-              cluding barley-enriched diets, need to be highlighted.
chemical properties of several barley cultivars, with the long-term           4. Strategies should be multifactorial and include messages from
goal of optimizing product production and consumer acceptance.                   health professionals, industry, and government.

                                                                                                               CEREAL FOODS WORLD / 271
   Compared with other research and commodity groups, work-                health measures to reduce the incidence, and ameliorate the im-
shop participants seemed to be more unified around a single goal:          pact, of such diseases. Barley is an interesting vehicle for genetic
to increase barley consumption in the population in general. This          studies of starch biosynthesis because 1) it is a diploid, allowing
unified goal provides a strong advantage—long-term relationships,          the use of direct phenotype screens for variation; 2) starch synthe-
based on mutual respect and the open exchange of information,              sis in barley produces a starch very similar to more genetically com-
among barley researchers, breeders, and the food industry can help         plex cereals, such as durum and bread wheat; and 3) high β-glu-
make barley an extremely successful food source. Increasing bar-           can levels raise the prospect of packaging enhancements in starch
ley consumption can be accomplished without altering the amount            quality with other health-promoting components of barley.
of other whole grains currently consumed.                                     In this work, novel barleys were developed using mutagenic and
                                                                           genetic engineering techniques targeting starch synthase genes and
          HISTORY OF BARLEY CULTIVATION                                    starch branching enzymes, respectively, resulting in the generation
                                                                           of starches with amylose contents greater than 70%. One line, Hi-
History of Barley as a Food Source. C. W. Newman, Newman As-               malaya292, results from a lesion in the starch synthase IIa gene and
sociates, Inc., Bozeman, MT.                                               has been extensively studied to examine its impact on indices of
                                                                           gastrointestinal and cardiovascular health.
   Historically, cities are the index of civilization, admired for their
palaces and temples, poetry, philosophy, art, and aqueducts, but
seldom for their granaries. Yet, the whole magnificent structure of        β-Glucan Compensated Low-Starch Mutants in Barley—A
the world’s first great civilizations (and those that followed) rested     New Pathway Detected by NIR Spectroscopy and Chemomet-
on granaries and the people who worked to fill them (Foods in              rics. L. Munck, B. Møller, and L. Nørgaard, The Royal Veterinary
History, Tannerhill, 1988). The story of barley as a food has been         and Agricultural University, Frederiksberg, Denmark.
unveiled by archeological discoveries in the Fertile Crescent dating
back to approximately 8000 B.C. Barley, considered one of the                 We took part in finding the first high-lysine barley mutant “Hi-
oldest cultivated crops, was a dietary mainstay of ancient civiliza-       proly” in 1966, using a ratio between Udy dye-binding and Kjel-
tions and continued to be an important diet constituent of working         dahl protein. This method was extensively used by the Risø Na-
class people until the end of the 19th century. Porridges, broths,         tional Laboratory (Denmark) during the 1980s to find a range of
hard biscuits, and flat breads made with barley were common die-           high-lysine barley mutants. Some of these, such as Risø mutants
tary fare, and fermentation, either by accident or for preservation,       13, 16, and 29, had almost normal lysine levels but had reduced
led to the creation of numerous types of alcoholic beverages in            starch levels. These mutants have been used by biotechnologists
every age.                                                                 as a model for exploring starch metabolism since 1990. We have
   Throughout historical reports, barley is referred to as a source        totally screened 11 mutants and normal controls using near infra-
of strength and stamina for athletes and persons involved in hard          red spectroscopy (NIR) and principal component analysis (PCA)
manual labor. The health benefits and medicinal aspects of barley          and found three clusters: normal, high lysine, and carbohydrate,
foods are stressed in ancient Egyptian, Ethiopian, Greek, and Ro-          including Risø mutants 13, 16, and 29 and three others (listed be-
man literature. Similar properties of barley foods also have been          low). The latter group in all six lines had high to extremely high β-
touted by civilizations extending from Asia to Scandinavia. Al-            glucan levels (up to 19.8% dm). Mutants 16 and 29 have normal
though wealthy Romans preferred wheat bread over barley bread,             amylose content according to the literature. Mutant 13 seems to be
barley was the choice of gladiators, who were called hordearii or          as high in β-glucan as ‘Prowashhonupana’ from Montana State
“barley men.” In almost every culture through the ages, barley foods       University (R. F. Eslick), which is a waxy genotype. It is hypothe-
are described as having almost mystical properties, and barley is          sized that Udy dye-binding may also react with β-glucan. Classifi-
often referred to as the “king of grain.” Barley became the major          cation by NIR spectroscopy and chemometrics produces a highly
grain grown in northern climates, especially Scotland and Scandi-          effective physical-chemical fingerprint and is an innovative com-
navia, because of its climatic adaptability.                               plement to biotechnological, genetic, plant breeding, and food in-
   Barley lost favor as a food grain in modern times primarily due         dustrial data, revealing surprising results without the a priori bias
to the improved conditions of the farming classes and the growth           of elaborate scientific theories.
and development of the wheat industry. Wheat breads and wheat-                         Genotype                       β-Glucan (% dm)
based breakfast cereal products have replaced much of the bakery
                                                                                       Mutant 29 lys 5g *                  8.9–13.4
markets for rye, oats, and barley because of texture, taste, appear-
                                                                                       Mutant 16 *                        12.0–16.6
ance, and increased availability. This is the result of improvements                   Mutant 95                          12.2
in wheat production, improved wheat baking quality, and the pref-                      Mutant 449                         12.4–13.5
erence of modern consumers for white, light, fluffy breads. With                       Mutant 1201 *                      15.4–15.6
increased consumer knowledge of the health benefits provided by                        Mutant 13 lys 5f                   16.5–19.8
dietary fiber, especially soluble dietary fiber and other whole-grain                  Bomi control                        4.9–6.8
constituents, barley-based foods have a good chance of regaining
their prominence and appreciation by consumers.
                                                                           References
                                                                           1. Jacobsen, S., Søndergaard, I., Møller, B., Desler, T., and Munck, L. A
        DEVELOPMENT OF BARLEY VARIETIES                                       chemometric evaluation of the underlying chemical patterns that sup-
                                                                              port near infrared spectroscopy of barley seeds as a tool for exploratory
Independent Genetic Mechanisms for the Production of High                     classification of endosperm genes and gene combinations. J. Cereal Sci.
Amylose Barleys. Matthew K. Morell (1), Zhongyi Li (1), Ahmed                 Submitted.
Regina (1), Sadiq Rahman (1), Anthony R. Bird (2), and David L.            2. Munck, L. Detecting diversity—A new holistic, exploratory approach. In
Topping (2). (1) CSIRO Plant Industry, Canberra ACT, Australia;               Diversity in Barley (Hordeum vulgare). R. von Bothmer, T. van Hintum,
(2) CSIRO Health Science and Nutrition, Adelaide, SA, Australia.              H. Knüpffer, and K. Sato, eds. Elsevier, Amsterdam, Denmark, 2003.
                                                                           3. Munck, L., Møller, B., Jacobsen, S., and Søndergaard, I. Spectral mul-
   Our studies have had two objectives: first, to understand the ge-          tivariate indicators for mutant endosperm genes evaluated by chemo-
netic control of starch synthesis in cereals, and second, to use this         metrics reveal a new mechanism for substituting starch with (1 3,
knowledge to generate cereals with the potential to enhance hu-               1 4)-β-glucan in barley. J. Cereal Sci. 40:213, 2004.
man health. The increase in “lifestyle” diseases, such as cardiovas-       4. Munck, L., Pram Nielsen, J., Møller, B., Jacobsen, S., Søndergaard, I.,
cular disease, bowel health disorders, and metabolic disorders, such          Engelsen, S. B., Nørgaard, L., and Bro, R. Exploring the phenotypic ex-
as type II diabetes, in both Western and developing nations is an             pression of a regulatory proteome-altering gene by spectroscopy and che-
incentive for the development of affordable, food-based preventative          mometrics. Anal. Chim. Acta 446:171, 2001.

272 / SEPTEMBER-OCTOBER 2005, VOL. 50, NO. 5
Hulless Barley: Does It Have a Future in the Mid-Atlantic USA?           ily by macrophages of the innate immune system, tumor necrosis
Robert J. Kratochvil, Department of Natural Resource Sciences and        factor alpha (TNFα), is involved in all of these disease states. Al-
Landscape Architecture, University of Maryland, College Park, MD.        though TNFα is required for a healthy immune system, too little
   Barley (Hordeum vulgare L.) production in the Mid-Atlantic Re-        prevents the immune system from providing an appropriate defense
gion of the United States has declined from nearly 500,000 acres         against infectious agents and too much leads to inflammatory dis-
in the early 1950s to 162,000 acres in 2004. The decreased de-           orders associated with chronic diseases. The objective of this study
mand for barley is attributed to quality factors. Mid-Atlantic farm-     was to demonstrate that several bioactive compounds found in bar-
ers have been reluctant to produce awned cultivars due to difficul-      ley have the potential to improve health through modulation of TNFα.
ties in harvesting them in this humid region. Breeders have responded       Barley contains many bioactive compounds that have demon-
by supplying awnless and tip-awned cultivars. However, these types       strated biological activities, such as reducing total and LDL cho-
of cultivars have lower test weights (42–45 lb bu–1) than awned          lesterol, postprandial glucose and insulin levels, and cancer and
cultivars (48 lb bu–1), giving them poor feed values (approximately      cardiovascular risks. What is not as well known about bioactive
75–80% of corn). One agronomic advantage that barley provided            compounds found in barley is the ability of β-glucan to increase
when double-crop soybean (Glycine max Merr.) production was              TNFα and the ability of bran components to decrease TNFα. Us-
introduced into the region during the late 1970s was an earlier har-     ing a model cell culture system (RAW 264.7 macrophages in DMEM,
vest date compared with wheat (Triticum aestivum L.), which allowed      10% FBS, 5% CO2, 37°C), we have shown that highly pure barley
earlier soybean planting. Barley was replaced with more profitable,      β-glucan (>91%; 10 µg/mL) and oat β-glucan (>97%; 300 µg/mL)
earlier maturing wheat cultivars in these systems by the mid-1980s,      stimulate macrophages to produce TNFα at 0.57 and 0.49 fg per
however. The Maryland Grain Producers’ Association (MGPA) has            cell, respectively (quantified by ELISA). β-Glucans from curdlan
been steadfast in its efforts to revive barley because they believe it   (50 µg/mL) and zymosan (50 µg/mL) produced significantly more
has advantages over wheat when preceding soybean. Most recently,         TNFα than the cereal glucans (5.76 and 3.84 fg per cell, respec-
MGPA investigated the feasibility of barley for ethanol produc-          tively). However, treatment of β-glucans from barley (10 µg/mL)
tion. Corn ethanol production in the United States has increased to      and oat (300 µg/mL) with lichenase (10 µ/µg) for 1 hr at 40°C sig-
3.4 billion gallons per year (2004), but no ethanol plants are lo-       nificantly (p > 0.05) increased TNFα production only in the oat β-
cated in the eastern United States. MGPA believes there is ade-          glucan samples (0.48–1.48 fg per cell). Curcumin, an anti-inflam-
quate demand for ethanol in this region and that barley would be a       matory dietary component of ginger, significantly inhibited
better feedstock than corn because an above-average corn market          production of TNFα by modified barley and oat β-glucans, 0.008
already exists. The feasibility study determined that commonly           and 0.144 fg per cell, respectively, but could only inhibit curdlan
grown hulled barley cultivars are unsuitable for ethanol produc-         stimulation by 10%. However, bran extracts (95% ethanol) from
tion. This finding did not discourage MGPA, however. Breeders at         barley and wheat completely inhibited all β-glucan stimulation
Virginia Polytechnic Institute and State University (VPI) have been      from these macrophages without necrosis. We have demonstrated
developing hulless barley cultivars while concurrently pursuing          that dietary components from cereal grains have the potential to
uses for the crop. MGPA and VPI teamed with researchers at the           modulate TNFα production. Differences in production of TNFα
USDA Eastern Regional Research Center to evaluate ethanol pro-           by different cereal β-glucans include differences in extraction meth-
duction using hulless barley. The tests indicated that hulless barley    ods and solution chemistry between barley and oat β-glucans.
would yield 4.7 gal of ethanol per 100 lb of grain versus 4.2 gal for
hulled barley. Additionally, the introduction of Asian soybean rust      Beta-Glucan Isolation/Concentration Technologies and Their
into the United States has renewed interest in barley for double-        Impact on Molecular Structure and Functionality. Thava Vasan-
crop soybean production. Because soybean planting can occur one          than and Feral Temelli, Department of Agricultural, Food and Nu-
to two weeks earlier than when following wheat, soybeans cropped         tritional Science, University of Alberta, Edmonton, AB, Canada.
with barley would be further advanced physiologically when rust
spores arrived and might avoid the disease.                                 Beta-glucan, a cell-wall component of cereal grains, exists in ap-
   Recent human nutrition studies indicate encouraging health ben-       preciable amounts in barley (up to 15%, w/w) and oat (up to 7%,
efits associated with increased consumption of barley. Mid-Atlantic      w/w). A number of clinical studies have demonstrated the health
farmers are centered in the heavily populated eastern United States,     benefits (i.e., lowering of blood cholesterol, regulation of blood glu-
where many opportunities likely exist for barley food markets.           cose levels, and stimulation of the immune system) of increasing
The Mid-Atlantic region is also in the nutrient-sensitive Chesa-         the level of barley and oat beta-glucans to physiologically effective
peake Bay watershed. Winter crops, like barley, are highly effec-        concentrations in the human diet. As a result, the food and supple-
tive at managing excessive nutrients. Producing enough hulless bar-      ment industries are increasingly interested in isolating and concen-
ley for a 30 million gallon ethanol plant would require nearly 190,000   trating this bioactive grain component on a commercial scale to
acres of crop, all of which would be grown as a winter cover crop.       incorporate it into their formulations. The health benefits of beta-
This would strongly complement the 2010 Maryland goal for 600,000        glucan have been attributed primarily to its ability to increase the
acres of cover crop. Monetary incentives to encourage cover-crop         viscosity of intestinal digesta. Therefore, it is important to preserve
production currently exist, and Maryland is exploring allowing           the native physicochemical properties of beta-glucan during isolation
cover crops to be harvested for grain. For these reasons, hulless        and concentration, especially molecular weight and physiological
barley in the U.S. Mid-Atlantic region has a bright future.              solubility, which influence the solution viscosity of beta-glucan.
                                                                            Protocols to concentrate beta-glucan include dry (dry-milling
                                                                         and sieving or air-classification) and wet (aqueous and aqueous-alka-
         BIOACTIVE COMPOUNDS IN BARLEY                                   line and alcohol-based enzymatic) techniques. When the grain is dry-
                                                                         milled into flour, which is the feed stock for dry and wet concen-
Bioactive Compounds in Barley—Thicker and Bitter Can Be                  tration techniques, it is made up of a mixture of particulates that are
Better. D. A. Pascoe (1) and R. G. Fulcher (2). (1) Department of        simple (i.e., fragments of cell wall fiber, starch, protein, etc.) and
Food Science & Nutrition, University of Minnesota, St. Paul, MN;         complex (i.e., particulates containing cell wall fiber plus starch,
(2) Department of Food Science, University of Manitoba, Win-             starch plus protein, cell wall fiber plus starch plus protein, etc.) in
nipeg, MB, Canada.                                                       nature. These particulates vary in size, shape, and density. Simple
   Barley is a nutritious cereal grain that offers consumers many        vibratory sieving can be used to concentrate particulates contain-
bioactive compounds that can help improve their health. A grow-          ing fiber and beta-glucan according to their size into a flour frac-
ing body of evidence suggests that the immune system plays a key         tion containing beta-glucan at up to ≈7–8%. Air-classification of the
underlying role in many chronic diseases, such as cardiovascular         flour can also separate and concentrate particulates rich in fiber
disease, cancer, obesity, and diabetes. A cytokine produced primar-      and beta-glucan primarily based on their shape and density. Through

                                                                                                             CEREAL FOODS WORLD / 273
optimization of air-classification parameters, such as flour feed rate,     vitro fermentation of fiber fractions and use human feces as inocu-
air flow rate, classifier wheel speed, etc., a fiber concentrate con-       lum. In the first part, 39 barley varieties from Scandinavia and Can-
taining up to ≈20–22% beta-glucan may be obtained. The major                ada with different genotypes (six- and two-row; hull and hulless)
drawback of dry techniques is that they yield fiber concentrates with       and amylose contents (waxy, normal, and high amylose) were ex-
a relatively low beta-glucan concentration, which impose techni-            tensively analyzed with an emphasis on polysaccharides. In the
cal challenges in food formulations.                                        second part, barley fractions were obtained by sequentially treat-
   Wet techniques can yield fiber concentrates with a higher beta-          ing grounded barley with ethanol, hexane, boiling water, and base
glucan concentration (>50%). The aqueous and aqueous-alkali tech-           to obtain water-soluble and -insoluble fractions. The fermentability
niques involve four major steps: 1) solubilization of beta-glucan in        of the fractions was monitored as differences in carbohydrate com-
water or aqueous alkali (alkali improves solubilization of beta-            position, production of low molecular weight fatty acids, gas produc-
glucan); 2) centrifugation of the slurry to separate the solid phase        tion, and diversity in bacterial growth. The latter was determined by
from the liquid phase containing solubilized beta-glucan; 3) acid           analysis of the gene(s) coding for ribosomal DNA (16S rDNA).
and/or heat precipitation and centrifugal removal of proteins from             Results from the first part of the study show that the hulless bar-
the liquid phase; and 4) recovery of beta-glucan from the liquid            ley varieties were lower in nonstarch polysaccharides content, but
phase by alcohol precipitation or simple drum- or tray-drying. Pro-         higher in protein and beta-glucan than the hulled samples. The
prietary variations in each of these steps have been employed by            arabinoxylan content was higher in hulled than in hulless samples.
different producers. Beta-glucan concentrates produced in bulk com-         Hulless varieties contained more soluble arabinoxylan than hulled
mercially through aqueous technologies show low solution viscos-            varieties. Hulless barley had a higher arabinose/xylose ratio, indi-
ity when reconstituted in water. This is due the fact that in the aqueous   cating a higher degree of branching in arabinoxylan. The waxy and
process beta-glucan is solubilized from the cell wall and endoge-           high-amylose varieties (atypical) were high in protein, beta-glucan,
nous enzymes, such as cellulase and beta-glucanase hydrolyze (the           and soluble fiber. The hulless and atypical amylose varieties ana-
beta-glucan molecule), decreasing its molecular weight. Also, in            lyzed seem to be suitable for human consumption where high sol-
an aqueous solution the hydrated beta-glucan molecules become               uble-fiber and nutritive contents are desirable.
highly prone to shear fragmentation during mixing and centrifuga-              Results from in vitro fermentation show that barley fraction WSM-
tion steps. Another disadvantage of the aqueous technologies is             AU (water-soluble material), containing approximately 90% beta-
the use of large quantities of water that need to be evaporated to dry      glucan, had the highest reduction in polymeric glucose, highest gas
the fiber concentrate, significantly increasing the cost of produc-         production, and largest pH reduction during fermentation. In con-
tion. Another aqueous technology for beta-glucan concentration solu-        trast, the alkali-insoluble material WUM-B-RES (containing both
bilizes beta-glucan and starch with the application of heat in the          beta-glucans and arabinoxylans) had a 60% reduction in arabi-
presence of thermostable alpha-amylase. The liquid phase contain-           noxylans, low gas production and low pH reduction. This was the
ing the solubilized beta-glucan and hydrolyzed starch is separated          only fraction in which arabinoxylans were degraded.
by centrifugation and dried to obtain a powder. Beta-glucan con-               Based on SCFA (short-chain fatty acid) formation the differences
centrations of up to 10% can be achieved using this technology.             between barley fractions were smaller. However, the beta-glucan
   Another promising and cost-effective technology, the alcohol-            fraction WSM-AU produced the highest level of SCFAs, mostly
based enzymatic technique, was recently introduced. Using this              acetic and propionic acids. Butyric acid was only detected in small
technique, grain flour is slurried in aqueous ethanol and treated           amounts. An increase in ethanol was also detected during fermen-
with special enzyme cocktails to hydrolyze protein and starch. Sub-         tation. At the end point different bacteria communities were ob-
sequently, the beta-glucan–enriched cell-wall fiber particulates that       served with different fiber substrates. Different rates of in vitro
are freed from starch and protein are recovered by simple filtration        fermentation between barley fractions indicate that water-soluble
techniques. In the presence of alcohol, beta-glucan is not solubi-          and -insoluble nonstarch polysaccharides function differently as
lized and remains intact within the cell wall. This technology yields       substrate for bacteria in the gastrointestinal tract.
fiber concentrates with superior beta-glucan characteristics (i.e.,
high molecular weight and viscosity) compared with those pro-                          BENEFICIAL EFFECTS OF BARLEY
duced using aqueous or aqueous-alkali technologies. Because beta-
glucan is not solubilized from the cell walls, potential hydrolysis         Health Effects of Barley Consumption. Judith Hallfrisch and Kay
by endogenous enzymes, such as cellulase and beta-glucanase, is             M. Behall, Diet & Human Performance Laboratory, Beltsville Hu-
minimized. In addition, shear fragmentation of the molecule does            man Nutrition Research Center, ARS, USDA, Beltsville, MD.
not occur, because beta-glucan remains unsolubilized throughout                Cardiovascular disease remains a major health problem in the
the process, preserving its original molecular weight and viscosity         United States. Consumption of soluble fiber, like that found in oats,
characteristics. Beta-glucan concentrations of up to 60% can be             has been recognized as beneficial in decreasing blood cholesterol
obtained using this technology. The effect of various processing            levels and other cardiovascular risk factors. Barley contains high
conditions on the physicochemical properties (i.e., molecular weight,       amounts of soluble fiber but is not extensively consumed in the
solubility, etc.) of cereal beta-glucans and how such effects influ-        United States. Two studies performed at the Beltsville Human Study
ence the physiological functionality of beta-glucan is an important         Facility investigated whether consumption of barley would reduce
topic for further research.                                                 cardiovascular risk factors comparably to reductions observed with
                                                                            other soluble-fiber sources.
                                                                               Moderately hypercholesterolemic men and women who were
Healthy Barley—Indications of Different Effects of Beta-Glucan              weight-stable for six months before the two studies and taking no
and Arabinoxylan Fractions. Stefan Sahlström (1), S. H. Knut-               medication known to affect lipid or glucose metabolism or blood
sen (1), E. Bråthen (1), A. K. Holtekjølen (1,2), K. Rudi (1), and I.       pressure consumed controlled step 1 diets for 17 weeks. After the
M. Aasen (3). (1) Matforsk, Norwegian Food Research Institute,              two-week adaptation period, three whole-grain diets containing sim-
Aas, Norway; (2) Department of Chemistry, Biotechnology and                 ilar amounts of total fiber but different amounts of soluble fiber (0,
Food Science, UMB, Aas, Norway; (3) SINTEF, Department of                   3, or 6 g of soluble fiber per 2,800 kcal per day) from 1) wheat flour
Biotechnology, Trondheim, Norway.                                           and flakes and brown rice; 2) 50% wheat and rice and 50% barley;
   The aim of our studies is to provide new information on the ef-          or 3) barley pearls, flour, and flakes, respectively, were included in
fects of components of barley on parameters with relevance to               the step 1 diet for five weeks each. Two fasting blood samples were
human diseases. Barley was selected as a cereal source because it           collected after a 12-hr fast before controlled feeding began and
is rich in important fiber components. The project has two main             weekly during each period. Triacylglycerol and total and HDL cho-
parts: 1) study the content and composition of polysaccharides in           lesterol concentrations were determined enzymatically, and lipid
a wider range of barley samples; and 2) establish a system for in           subclass fractions were measured by nuclear magnetic resonance

274 / SEPTEMBER-OCTOBER 2005, VOL. 50, NO. 5
spectroscopy. Data were statistically analyzed using analysis of vari-    Extracted Barley β-Glucan Improves CVD Risk Factors and
ance with a mixed model procedure.                                        Other Biomarkers in a Population of Generally Healthy Hyper-
   Total and LDL cholesterol were significantly lower when the diet       cholesterolemic Men and Women. Joel J. Pins (1), Tatyana Sham-
contained 3 or 6 g of β-glucan from barley; the greatest change           liyan (1), Lore W. Kolberg (2), Leslie L. Curry (2), and Joseph M.
occurred in men and postmenopausal women. In study 1, total cho-          Keenan (1). (1) University of Minnesota, Minneapolis, MN; (2)
lesterol concentrations for men after consumption of 3 or 6 g of β-glu-   Cargill Health and Food Technologies, Wayzata, MN.
can were17 and 20%, respectively, lower than prestudy concentra-             Whole-barley foods, like oats, are rich in soluble fibers, particu-
tions. In study 2, the greatest decrease was observed after consuming     larly β-glucan. Previous studies using diets rich in barley have re-
the high β-glucan diet: 15% for men; 11% for postmenopausal               ported a significant improvement in blood lipids. However, barley
women; and 8% for premenopausal women. Calculated LDL cho-                and processed barley foods are not commonly consumed in the
lesterol concentrations followed the same significant pattern of re-      United States. Therefore, we conducted a double-blind, placebo-
duction observed for total cholesterol. HDL cholesterol and triacyl-      controlled, five-group parallel study to determine the effects of ex-
glycerol concentrations did not differ among the three levels of          tracted barley β-glucan on CVD (cardiovascular disease) biomarkers.
dietary β-glucan in either study. Compared with prestudy concen-          Treatment groups included either low (LMW) or high molecular
trations, HDL cholesterol in study 1 was significantly lower after        weight (HMW) β-glucan at both 3- and 5-g doses. Treatment de-
the step 1 and medium-soluble fiber diets and in study 2 after all        livery was both a ready-to-eat cereal and juice. Generally healthy hy-
three test diets. In both studies, the ratio of total to HDL choles-      percholesterolemic (LDL cholesterol 130–190 mg/dL) men (n = 76)
terol was highest after the low soluble-fiber diet. LDL particle size     and women (n = 79) between the ages of 25 and 73 years who com-
showed significant variation between the diets, but no difference         pleted a four-week diet phase (modified fat diet) were randomly
was observed due to the amount of soluble fiber in the diet. LDL          allocated to one of the four treatment groups or the control group.
mean size and number of particles remained in the high-risk range         Additionally, treatment groups were stratified by metabolic status.
after all diets in both studies. These results indicate that barley may   Metabolic syndrome patients were identified using the ATP III guide-
be an effective addition to a healthy diet to help lower total and LDL    line definition and/or elevated fasting insulin levels of ≥10 µU/L.
cholesterol in both men and women.                                        All subjects consumed the treatment or control twice daily for six
                                                                          weeks. Subjects were counseled to maintain the modified fat diet
Sustagrain® Barley—A Natural Whole Grain Barley for Today’s               and all other lifestyle habits throughout the treatment period.
Health and Wellness Needs. Elizabeth A. Arndt, ConAgra Foods,             Three-day food records from weeks 1 and 6 of treatment were col-
Inc., Omaha, NE.                                                          lected. Fasted blood samples were collected pre- and postinter-
                                                                          vention, and blood lipids, apolipoproteins, LDL number and size,
   Sustagrain is a natural, waxy, hulless variety of barley that has a    C-reactive protein, and other CVD biomarkers were determined.
unique macronutrient composition and special health benefits com-         Patients in the metabolic stratus also participated in a 4-hr mixed
pared with other common cereal grains. Sustagrain barley was de-          meal challenge, in which baseline and postprandial insulin, glucose,
veloped as the variety Prowashonupana through a conventional bar-         C-peptide, triglycerides, and unesterified fatty acids were measured,
ley breeding program at Montana State University and is a whole           and underwent a DEXA (dual energy x-ray absortiometry) scan to
grain in all processed forms.                                             evaluate body composition. Fasted blood lipids were unchanged in
   Sustagrain barley has a unique carbohydrate distribution, with at      the control group. Total and LDL cholesterol were significantly re-
least 30% dietary fiber and only 30% starch, which is 2–3 times           duced in all treatment groups. Treatment also improved fasted tri-
the amount of fiber and approximately half the starch compared            glycerides and other CVD biomarkers. In general, results did not
with other common cereal grains. Approximately half of the die-           vary by molecular weight but did vary by dose and metabolic status.
tary fiber is beta-glucan. Sustagrain is a high-lysine barley that        In conclusion, both doses of extracted LMW and HMW barley β-
delivers other important whole-grain nutrients as well, including         glucan improved blood lipids and other CVD biomarkers over a
healthy lipids, vitamins, minerals, and phytonutrients. The total anti-   six-week treatment period.
oxidant capacity of Sustagrain is 4,600 µmol Trolox equivalents
per 100 g.
   Adequate intake of whole-grain foods has been linked with re-          Soluble Fibers Prevent Insulin Resistance in Hamsters Fed High
duced risk for heart disease, type II diabetes, certain cancers, all-     Saturated Fat Diets. Wallace H. Yokoyama, USDA, ARS, Western
cause mortality, and weight management. The carbohydrate pro-             Regional Research Center, Albany, CA.
file of Sustagrain barley readily lends this whole-grain ingredient          America and other developed countries are experiencing an epi-
to use in foods that deliver added benefits, particularly for blood       demic of obesity and type II diabetes. Type II diabetes is usually
sugar management, digestive health, and weight management.                preceded by a group of characteristics called the metabolic syn-
   Standard in vivo glycemic testing procedures have shown that           drome. These characteristics include obesity, insulin resistance, high
Sustagrain barley is effective for lowering postprandial blood glu-       blood pressure, abdominal obesity, high blood cholesterol, and high
cose response in a variety of product applications, including hot         blood fasting glucose and insulin. During this phase preceding type
cereals, pilafs, breads, bars, and beverages. Sustagrain barley, eaten    II diabetes, cellular damage occurs, resulting in type II diabetes.
as part of breakfast, extended between-meal fasting and improved          Type II diabetes (or adult onset diabetes), once rarely found in
glucose tolerance at the lunch meal. Consumption of a high-fiber,         young people, is becoming increasingly common in school chil-
low glycemic-index diet that includes foods such as Sustagrain bar-       dren. Barley may help prevent insulin resistance and resulting type
ley, may reduce the risk for developing type II diabetes.                 II diabetes and delay the onset of diabetes in individuals who are
   Eating a diet rich in whole-grain foods also is important for di-      already insulin resistant. Because elevated blood glucose is asso-
gestive health and may improve weight management. The average             ciated with diabetes, there is often a negative association between
American fiber intake is approximately half of the 25-g daily value       cereal foods, a source of glucose, by consumers. Barley and oats are
recommended for a 2,000 calorie diet. Sustagrain barley is higher         two of the best food sources of soluble dietary fiber. Most fruits,
in fiber compared with other common cereal grains: a 30-g serving         vegetables, and other cereal grains contain predominantly insoluble
provides 9 g of dietary fiber. Sustagrain barley was significantly        dietary fibers. The research presented here shows that some soluble
less absorbed compared with a standard barley variety, as indi-           fibers can overcome the adverse metabolic effects of diets high in
cated by breath hydrogen and carbon dioxide outputs measured af-          saturated fat.
ter consumption of 13C-enriched barley pilaf from each variety. Con-         Our research using Syrian hamsters suggests that saturated fats
sumption of whole-grain foods that are comparatively higher in            may be a direct cause of insulin resistance and elevated blood glu-
fiber and less well absorbed may provide additional benefits for          cose and symptoms such as high blood pressure, elevated choles-
digestive health and weight management.                                   terol, and other characteristics of metabolic syndrome. However,

                                                                                                             CEREAL FOODS WORLD / 275
the harmful effects of saturated fats can be overcome in the pres-         ter- and fat-soluble antioxidants, which help suppress free radicals
ence of soluble fibers, including beta-glucan from barley. Male Syr-       and prevent cell damage.
ian hamsters have been used extensively to study lipid metabolism             In addition to measuring insulin resistance, blood parameters, and
because they have many similarities with humans.                           abdominal fat weight, we also examined the cell structure of the
   In this study hamsters were fed a diet similar in fat calories to       liver, skeletal muscle, pancreas, adipose tissue, and heart muscle
the average American diet. The fat component of the diet was either        by transmission electron microscopy (TEM). All tissues from HF
5 or 20% fat (low [LF] or high [HF] fat). The percentage of fat            fed animals had fat vacuoles that were not present in the animals
energy in the HF diet was calculated to be 37.3%, compared with            fed either the LF diet or soluble fiber from barley, HPMC, and
the 33–37% mean fat intake of males 19–50 years of age (1984–              psyllium. In some tissues, damage to nuclear membranes was ob-
1995) in the United States (1). The fat composition was the same:          served. Insulin normally stored as granules in the beta cells of the
75% butterfat and 25% corn oil. The predominant fatty acids were           pancreas were depleted in the HF, insoluble cellulose fed animals.
oleic (25%), palmitic (22%), linoleic (17%), and stearic (10%). The        Animals fed HF and soluble fiber diets had some restoration of
remainder of the LF and HF diets contained 20% casein and 7.7%             insulin storage. Adipose cell size was larger in HF, insoluble cel-
dietary fiber. The hamsters were fed for four weeks, and a stan-           lulose fed animals.
dard method of determining whole-body insulin resistance, the eu-             To expand our understanding of metabolic differences, a micro-
glycemic insulinemic clamp, was used to determine insulin resistance.      array analysis of liver tissues from animals fed the LF, HF, or
As part of this test, a constant flow of insulin is administered to        HFHPMC diet was conducted. A microarray chip containing ap-
the animal through a catheter. The insulin administration causes           proximately 8,000 genes was used to identify differences in gene
glucose uptake by the muscle and other peripheral tissues. The level       expression. The results were consistent with the hypothesis that sat-
of glucose is monitored through a second catheter. If the blood            urated fat is directly involved in insulin resistance and elevated blood
glucose concentration drops below the original level before insulin        glucose. The key enzyme for converting saturated to unsaturated
administration, more glucose is administered. The rate of glucose          fat was expressed at a higher level in animals fed the saturated fat
administration is a measure of insulin resistance. Higher uptake by        diet containing insoluble cellulose compared with animals fed the
the peripheral tissues and greater glucose administration is a sign        HF diet containing HPMC or soluble cellulose. Enzymes in the fat
of good insulin sensitivity. Conversely, decreased uptake is a sign        oxidation pathway were also elevated in the animals fed a HF diet
of insulin resistance.                                                     and insoluble cellulose.
   The euglycemic insulinemic clamp data are shown in the follow-             In conclusion, we found that saturated fat, not carbohydrates, in
ing table.                                                                 the diets of test animals caused insulin resistance. Insulin resistance
                                                                           even in diets containing high levels of saturated fats could be re-
                      Low Fat      High Fat          HFBa   HFHPMCb
                                                                           versed by substituting soluble fibers for insoluble fibers. In ani-
Glucose ratec                                                              mals that were insulin resistant, the liver, and possibly other tissues,
  (µmol/kg/min)       106 ± 8.5    55 ± 6.4      85 ± 5.8   109 ± 3.5      resorted to metabolizing more fat for energy. Fat oxidation is thought
Abdominal fat pad                                                          to result in permanent damage to tissues, ultimately resulting in
  (mg)              2,133 ± 164 2,990 ± 379 2,570 ± 228 1,750 ± 221
Plasma insulin
                                                                           diabetes. In addition to reducing insulin resistance and perhaps pre-
  (pmol/L)            76.3 ± 10   121.4 ± 22   111.0 ± 14    47.9 ± 4      venting or delaying diabetes, barley also contains antioxidants that
a
                                                                           may help to retard cell damage caused by free radicals.
  High-fat diet with barley.
b High-fat diet with hydroxypropylmethylcellulose.
c Glucose clamp.                                                           Acknowledgments
                                                                             This research was funded by the U.S. Department of Agriculture.
   The hamsters fed high-fat, high saturated-fat diets containing bar-
ley or the semisynthetic soluble cellulose hydroxypropylmethylcel-         References
lulose (HPMC) had significantly higher glucose administration rates        1. Kennedy, E. T., Bowman, S. A., and Powell, R. Dietary-fat intake in the
than hamsters fed the high-fat diet. The dietary fiber in the LF and          US population. J. Am. Coll. Nutr. 18:207, 1999.
                                                                           2. Rivellese, A. A., and Lilli, S. Quality of dietary fatty acids, insulin sen-
HF fed animals was insoluble microcrystalline cellulose. A form
                                                                              sitivity and type 2 diabetes. Biomed. Pharmacother. 57:84, 2003.
of high-viscosity HPMC, a modified cellulose, was used in the study.
Animals on the HF diet had a significantly lower glucose admini-
stration rate than those on the LF diet. In a subsequent study, ham-                   SENSORY PROPERTIES OF BARLEY
sters fed 20% corn oil alone did not develop signs of insulin resis-
tance, such as fat infiltration of tissues. Abdominal adiposity, another   Consumption of Whole Grains Containing Beta-Glucan Altered
symptom of metabolic syndrome in humans, was also lower in ani-            Short-Term Satiety and Glycemic Response in Overweight Wom-
mals fed soluble fibers, although overall body weight gain was not         en. Hyunsook Kim, Kay M. Behall, and Joan M. Conway, Diet &
different in this four-week time period. Plasma insulin was lower          Human Performance Laboratory, Beltsville Human Nutrition Re-
in the HFHPMC fed animals, although not in the HFB fed animals.            search Center, ARS, USDA, Beltsville, MD.
Barley, the source of soluble beta-glucan, was fed as a flour. Because        Regulation of satiety after soluble-fiber intake has been proposed
beta-glucans reside in the cell wall and must diffuse out during pas-      as a strategy to reduce weight gain. Beta-glucan, a predominant wa-
sage through the digestive system, lower activity is expected.             ter-soluble fiber found in oats and barley, has a significant choles-
   The data show that carbohydrates have little or no effect on in-        terol-lowering effect and improves acute glycemic response. How-
creasing insulin resistance. All the HF diets contained the same           ever, the role of beta-glucan in the regulation of satiety and weight
amount and type of carbohydrate. In fact, the LF diet, our reference       management is not clear. To determine the effect of a meal with and
for good glucose disposal and high insulin sensitivity, by necessity       without beta-glucan (BG) on satiety and glucose response, four iso-
had a higher amount of carbohydrate to make up the difference be-          caloric test meals were fed to overweight subjects (10 women;
tween the LF (5% fat) and HF (20% fat) diets. The adverse effects          nine men; BMI = 30.1 ± 0.8; age = 53.9 ± 2.2 years). Using a ran-
of saturated fats on insulin sensitivity has been reviewed recently        domized crossover design, the treatments included glucose (75 g),
by Rivellese and Lilli (2). Some of the effects include down regu-         wheat (0 g of BG [0BG]), wheat-barley mixture (1 g of BG [1BG]),
lation of the glucose transport protein, GLUT4, and subsequent de-         and barley (2 g of BG [2BG]) served as cooked cereal. Macronu-
crease of glucose transport into muscle and impairment of glyco-           trient and water intake were controlled across all cereal treatments.
gen synthesis. The absence or lower availability of glucose causes         Subjects were fed control diets (15% protein, 50% carbohydrate,
cells to use fat for energy. The metabolism of fat is thought to gen-      and 35% fat) for one day prior to the test meals. Previously vali-
erate more free radicals and result in cellular damage. In addition        dated visual analog scales (VAS) were used to determine perceived
to restoring insulin sensitivity, barley is a good source of both wa-      hunger, fullness, satisfaction, nausea, thirst, and drowsiness. VAS is

276 / SEPTEMBER-OCTOBER 2005, VOL. 50, NO. 5
composed of a horizontal line (100 mm) anchored by words or                bran extracts to further increase the nutritional benefits of the tor-
phrases at positions corresponding to their geometric mean magni-          tillas resulted in positive textural attributes depending on which
tude estimates. The energy and water intake of a standardized lunch        barley genotype was used for the base flour. Selected genotypes
were measured at 2 hr after consumption of test meals. Blood glu-          with specific starch properties, milling characteristics, and colors
cose and VAS ratings were measured periodically from fasting un-           were identified for the production of high-fiber tortillas with op-
til 2 hrs after consumption of test meals. In women, peak glucose          timized quality, as measured by both sensory and instrumental
responses and area under the curve (AUC) were significantly re-            techniques.
duced after consumption of a meal with 2BG compared with 0BG                   Genotype differences were also observed for response to heat and
and 1BG meals. Mean VAS ratings for “hunger” and “how much I               moisture treatments in the development of novel whole-grain bar-
can eat” were significantly reduced at 15 and 30 min after consump-        ley products. These specialized infrared heat treatments influenced
tion of 1BG and 2BG meals compared with 0BG meals. However,                RVA viscosity, beta-glucan acid extract viscosity, water absorp-
in men, the acute effects of beta-glucan on glucose and VAS ratings        tion, and product texture to varying degrees depending on geno-
of satiety were weak. Short-term energy and water intake were not          type. This variation in response to heat treatment suggests applica-
affected by beta-glucan intake in either women or men. The data            tions in very different products. For most genotypes, infrared heat
indicate that acute reduction of the glycemic response and hunger          processing did not alter beta-glucan content but did result in in-
ratings in overweight women requires consumption of at least 2             creased beta-glucan viscosity.
and 1 g of beta-glucan per meal, respectively. However, in over-               In the third food system studied, content, viscosity, and water
weight men greater amounts of beta-glucan per meal may be re-              extractability of beta-glucan in various barley fractions and geno-
quired to achieve substantial glucose and satiety rating effects.          types had implications for development of barley beverages. Geno-
This study further suggests the beneficial effects of beta-glucan on       type, milling fraction, and heat treatment all affected beta-glucan
glucose metabolism and, possibly, satiety control. Studies in a lar-       extractability and viscosity. Cultivars with improved beta-glucan ex-
ger population are required to verify the effect of beta-glucan            tractability and viscosity might offer greater opportunities for devel-
based on gender.                                                           oping food products with improved health benefits.

Utilization of Diverse Barley Properties To Maximize Food Prod-                       BARLEY HEALTH CLAIM PETITION
uct Quality. N. Ames (1), C. Rhymer (1), D. Ryland (1), B. Ross-
nagel (2), M. Therrien (3), and S. Dua (1). (1) Agriculture & Agri-        Barley Beta-Glucan Soluble Fiber and Barley Products Contain-
Food Canada, Cereal Research Centre, Winnipeg, MB, Canada; (2)             ing Beta-Glucan Soluble Fiber and Coronary Heart Disease: A
University of Saskatchewan, Saskatoon, SK, Canada; (3) Agricul-            Petition for an Unqualified Health Claim: Petition Overview and
ture & Agri-Food Canada, Brandon, MB, Canada.                              Status. Francis Webster, Francis Webster & Associates, Branson, MO.
   Given the potential health benefits and unique variability asso-           In 1997 the FDA authorized the first food ingredient health claim
ciated with specific barley genotypes, barley products have the abil-      (21 CFR 101.81) associating the consumption of diets low in satu-
ity to provide consumers with a variety of high-fiber, low glyce-          rated fat and cholesterol that included soluble fiber (beta-glucan)
mic-index foods. The challenge lies in the successful application          from oats with a reduced risk of coronary heart disease (CHD).
of the unique functional properties of different genotypes when            Because barley is also a rich source of beta-glucan soluble fiber,
developing barley end products. This research evaluated the utili-         the National Barley Foods Council (NBFC) initiated the develop-
zation of barley genotypes with diverse characteristics in three           ment of a petition requesting that 21 CFR 101.81 be amended to
types of food systems. The barley genotypes studied varied in func-        include barley as a source of beta-glucan soluble fiber associated
tional and nutritional characteristics, such as beta-glucan content        with reduced risk of CHD. The subsequent document, “Petition for
and viscosity, starch composition and content, protein, and total die-     Unqualified Health Claim: Barley β-Glucan Soluble Fiber and Bar-
tary fiber. Initial experimentation revealed that milled and blended       ley Products Containing β-Glucan Soluble Fiber and Coronary Heart
barley flour was well suited to the type of dough and baked-product        Disease,” was accepted by the FDA on November 11, 2004 (Docket
system used with tortillas. However, genotype significantly affected       No. 2004P-0512). The petition presents a detailed review of barley
the texture, appearance, and processing quality of fresh and frozen        and oat β-glucan physical and chemical attributes and the results
tortillas made from 100% barley flour and water. Principal com-            of clinical trials investigating the efficacy of barley β-glucan soluble
ponent analysis involving chemical and physical attributes of ap-          fiber in reducing cholesterol. The reviews clearly demonstrate that
proximately 25 Canadian barley genotypes (cultivars and breeding           barley and oat β-glucan soluble fibers are essentially equivalent on a
lines) indicated a relationship between beta-glucan content and in-        physical, chemical, and functional (cholesterol lowering) basis. Thus,
creased tortilla rollability, reduced chewiness, and reduced hardness.     the NBFC proposed that 21 CFR 101.81 (2)(i)(G)(1) be amended to
Total starch and amylose contents were correlated with greater             read: “(1) 3 g or more per day of β-glucan soluble fiber from whole
chewiness and increased hardness. Nutritional and textural stabil-         oats or barley. Eligible products to include but not be limited to
ity throughout processing were also studied. Freezing had little ef-       pearl, flakes, grits, meal, flour, β-glucan enriched meal or flour
fect on tortilla texture or beta-glucan, but color was affected to vary-   fractions and bran manufactured using standard milling techniques
ing degrees depending on genotype. Addition of concentrated barley         and providing at least 4% (dwb) β-glucan soluble fiber.”




                                                                                                               CEREAL FOODS WORLD / 277

								
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