Barley News & Updates

Are you or a loved one suffering from heart disease or diabetes? The answer is likely yes, since Americans are increasingly at risk for premature death from both cardiovascular disease and diabetes due to our increasing weight, elevated cholesterol, high blood pressure, and abnormal blood sugars.

You can, however, take heart help is at hand. BARLEY is now recognized as an important part of a delicious, hearthealthy lifestyle. Isn’t it wonderful that something so cheap, natural, tasty, and satisfying is also so good for you?

Barley good for you? Yes, barley. Food barley. Beer barley is another matter. Suffice it to say that the path to better health is not paved with beer bottles. While good beer may have therapeutic and medicinal properties, as widely asserted in Czech Republic, that is a story told elsewhere. In fact, barley for beer and barley for food differ in one very significant factor: beta-glucan.

Barley for beer must be low in beta-glucan and barley for food must be high in betaglucan.  Beta-glucan is the primary building block of cell walls in the grains of both barley and oats. Wheat and rye have cell walls too, but they don’t contain beta-glucan.

In fact, a diet high in refined grains, sugars, and excessive saturated fats, puts you at high risk for heart disease and diabetes. What makes beta-glucan so special (for food) is that it is a source of soluble dietary fiber. Fiber is so vital for good health that the Institute of Medicine recommends at least 25 grams per day for everyone over the age of four.

Barley is a rich source of both types of fiber both soluble and insoluble. However, researchers have identified beta-glucan as the primary component in barley that is responsible for lowering cholesterol. Based on scientific evidence, the Food and Drug Administration (FDA) finalized a rule in 2006 allowing barley foods to carry a health claim specific to soluble fiber and coronary heart disease. Qualifying products may use the following claim:

Soluble fiber from foods such as [name of food], as part of a diet low in

saturated fat and cholesterol, may reduce the risk of heart disease. A serving of

[name of food] supplies [x] grams of the soluble fiber necessary per day to have

this effect.

For history and science buffs, here’s a brief history of barley foods and beer, and an explanation of why beta-glucan is the brewer’s bane and dieter’s delight. About 10,000 years ago, when the Middle East was a less fractious place, some hungry and observant human took a sideways look at the grain on a spiny-looking ancestral barley plant and thought hmm ... that looks good enough to eat. One thing led to another, plants were domesticated and civilization flourished.

Most folks found they preferred to eat food made from wheat, rather than barley. On the other hand, barley grain served as the perfect substrate for tasty feel-good beverages. The primary food distinction between wheat and barley is that in a dough made from wheat flour will rise whereas a dough made from barley flour will not. The end result is that wheat flour is great for making light yeast breads and barley flour is great for making doorstops. However, malted barley has the perfect balance of protein and starch to feed alcohol-producing yeasts and thus to make beer.

For 9,000 years, the food and beverage uses of barley went hand-in-hand. On the whole, barley foods were for the poor. One of the tastier tidbits of barley food history is that the Roman gladiators were called the hordearii (barley men) because they subsisted on barley bread. One can surmise however, that the gladiators had no more interest in eating barley bread than in fighting lions. They just weren’t offered much of a choice. Scottish peasants, whom we may associate more with oats than barley, also had few choices. They apparently subsisted morning, noon, and night on barley porridge, with a side of

boiled greens on a good day. In Tibet, barley was, and continues to be, an essential part of the daily diet. Toasted barley flour, along with green tea and rancid yak butter, is used to make a food called tsampa. Special barley foods continue to be popular in some regions and may have unique health-promoting properties. For example, dakos is a traditional barley rusk on the island of Crete. Local bakeries use flour milled from whole (hulled) barley. In some cases, even the awns are ground with the grain. This whole grain barley food, awns and all, is thought to be one of the reasons for the low rate of colon cancer in the Cretan region.

In the rest of Europe, barley foods, with their negative associations of subsistence, bondage, and poverty, were gradually, gratefully, and generally replaced by wheat-based foods. Around 200 years ago, plant breeders began selecting barley and wheat in earnest, leading to the very distinct wheat and barley varieties of today. Worldwide (and in Oregon) most barley today is used for animal feed, but there is little added value.

Currently, the greatest value lies in malting barley. Malting barleys varieties are selected for low beta-glucan in order to give the yeast easier access to starch and protein inside each cell. A few breeders, anticipating a market for human food barley, selected for the opposite character high beta-glucan, in order to capitalize on the nutritional qualities of barley grain and the new food claim allowed by FDA. Two traits associated with this first generation of food barley varieties are hulless grain and waxy starch.

Almost all feed and malt barley varieties have adhering hulls. Food barley grain that has an adhering hull is pearled to remove the hull. While pearling leads to a loss of bran and its nutritional components, the total beta-glucan content is not affected since there is more beta-glucan in the endosperm than in the bran. A variant form of a gene called nud (which stands for grain nudity) causes the hull not to adhere and the grain threshes clean, just like wheat. One of the most descriptive barley variety names is the hulless (nud) cultivar Godiva’.

The jury is still out on whether the hulless (a.k.a. naked) trait is desirable. Hulless varieties may have germination and/or seedling vigor issues that can lead to lower yields, particularly under stressful field conditions. On the chromosome as Nud, there is a gene called GBSS1, which encodes an enzyme called granule bound starch synthase. GBSS1 is involved in synthesis of the amylose fraction of barley starch. When GBSS1 is functional, barley starch consists of ~ 25% amylose and 75% amylopectin. When GBBS1 is not functional (due to a naturally occurring mutation involving loss of ~ 400 base pairs of DNA), less amylose is produced, leading to a ratio of ~ 5% amylose and 95% amylopectin. The higher amylopectin content causes the starch to be waxy, and waxy

starch varieties usually have a higher beta-glucan content.

Waxy starch also has a number of other interesting properties for baking and other food use. Breeders have selected for waxy starch in order to increase beta-glucan content and add novelty and value to food varieties. Many of these waxy varieties are also hulless.  Two familiar examples in the US are Merlin’ and Waxbar’. There are also hulled waxy barleys an example is Salute’. It is also possible to get high beta-glucan with a nonwaxy starch and to have waxy starch with lower beta-glucan. In other words, all possible combos of hull adherence, starch type, and beta-glucan content are currently available.

One trait that all food barley varieties adapted to the Pacific Northwest of the US have in common is spring habit. This means they do not have sufficient cold tolerance for fallsowing in Oregon, Idaho, or Washington. There are compelling reasons including water use efficiency and high yield for growing winter barley rather than spring barley in this region.

An obvious goal is the development of winter food barley varieties. Such varieties will need to be cold tolerant, high in beta-glucan, and high yielding in both the dryland and irrigated environments of the Pacific Northwest. Creating a whole new breeding program based on crossing spring x winter varieties and selecting, based on trait expression alone, for cold tolerance, yield, and high beta-glucan is a tall order.

With support from the Oregon Grains Commission and Idaho Barley Commission, we have applied the latest in molecular breeding technology to the very focused development of winter food barley. The technique is called marker-assisted selection (MAS). MAS uses markers (differences in DNA sequence between varieties) to increase the efficiency of selection for target traits. In this application, plants with the correct DNA markers in

genes associated with low temperature tolerance and high beta-glucan are selected at the seedling stage in the greenhouse. Plants with the wrong markers are discarded. Thus, only plants with a high probability of being cold tolerant and having high beta-glucan advance to field testing.

The cold tolerance-related genes we targeted are two genes that determine vernalization response (Vrn-H1 and Vrn-H2). Vernalization sensitivity means that a variety will not flower until it has experienced a sufficient period of low temperature. There is excellent evidence that vernalization sensitivity is not required for cold tolerance. However, there is good evidence that vernalization sensitivity can give a boost to cold tolerance - like adding a turbocharger to a low horsepower engine.

In order to get high beta-glucan, we used a marker for the non-functional (waxy) form of GBSS1. In order to maximize the likelihood of achieving high yield and adaptation to fall-sown conditions in the Pacific Northwest, we used two winter varieties (Strider’ and Luca’) as parents. Strider is a hulled six-row feed variety released by Oregon State University and Luca is a Hungarian hulled two-row feed variety. Strider and Luca are the donors of the target vernalization gene, while Merlin and Waxbar are the spring donors of

the waxy gene.

In order to maximize the probability of recovering winter waxy types, we used breeding methods called backcrossing and double crossing, along with MAS. Crossing Luca by Waxbar and then crossing back to Luca is an example of a backcross and is abbreviated as L/W//L. A double cross involving three parents (Luca, Merlin, and Waxbar) is abbreviated as L/W//L/M. In all, we made two backcross populations involving Luca, Waxbar, and Merlin; a double cross population involving Luca, Merlin, and Waxbar; and a backcross population involving Strider and Merlin. Molecular markers were used at each generation, leading to the first field assessment at Hyslop Farm (Corvallis, Oregon)

in 2007/2008 (see Timeline).

We will measure beta-glucan content of these lines after harvest in 2008 and advance lines selected for high beta-glucan content and agronomic performance to field tests at as many locations in Oregon and Idaho as seed allows in 2008/2009. We have also crossed these potential winter waxy food barleys to the most cold tolerant varieties from Germany and Nebraska in preparation for future cycles of MAS. The intent is to create a product stream of high beta-glucan winter food barley varieties, waxy and non-waxy, hulled and hulless, 2-row and 6-row.

Americans will be looking to barley for health improvements. Thanks to Oregon and Idaho barley assessment dollars and the USDA-CSREES STEEP program, winter food barley varieties are on the horizon.

For more information on food barley and links to a host of barley food resources and recipes, see the Barley Foods section of www.barleyworld.org  

Timeline for development of winter waxy food barley germplasm using marker assisted selection (MAS).