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Meat Safety: It All Works Out in the Wash

When it comes to the safety of the U.S. beef supply, everything works out in the wash--the hide wash, that is.

Scientists with the Agricultural Research Service (ARS) developed a hide-washing tool that has significantly improved the safety of U.S. beef while saving the beef industry millions of dollars each year. An estimated 50 percent of U.S. feedlot-raised beef cattle undergo the washing treatment, which has reduced the national incidence of pathogenic Escherichia coli in ground beef samples by about 43 percent.

The tool was developed by ARS scientists at the Roman L. Hruska U.S. Meat Animal Research Center (USMARC) in Clay Center, Neb. The research team included microbiologists Terry Arthur and Joseph Bosilevac, food technologists Steven Shackelford and Tommy Wheeler, and center director Mohammad Koohmaraie, formerly with ARS.

The U.S Centers for Disease Control and Prevention estimate that E. coli O157:H7 causes nearly 73,000 illnesses every year in the United States. Following a 1993 outbreak, the USMARC scientists launched a massive investigation into the pathogen. Their work was the first to show that the principle source of E. coli O157:H7 in ground beef is fecal contamination on cowhides.

Before, most intervention efforts had focused on eliminating the pathogenic bacteria from feces. The new findings led to a paradigm shift and the development of improved, hide-targeted intervention techniques to reduce and eliminate pathogenic E. coli O157:H7 and other dangerous microorganisms.

The hide-washing system works by using a high-pressure-water wash that removes excess organic matter from the cattle's hides, which are then sprayed with an antibacterial compound.

The scientists also have demonstrated that several chemical compounds can be effectively used for pathogen removal.

Read more about the research in the July 2008 issue of Agricultural Research magazine.

ARS is a scientific research agency of the U.S. Department of Agriculture.

New Research Presented on Peanut Components

Fat free peanut flour, whole peanuts and peanut oil all may have cardio-protective properties, results from a new animal study suggest. Agricultural Research Service (ARS) scientists are presenting the findings at this week's Institute of Food Technologists 2008 Annual Meeting in New Orleans, La.

For the study, male hamsters were randomly divided into four groups. Each group of nearly 20 hamsters was fed one of four different diets, all of which were high-fat and high-cholesterol.

Each diet consisted of nearly equal percentages of fats, carbohydrates and proteins. For three of the four test diets, equivalent amounts of food component were substituted with fat-free peanut flour, peanut oil or peanuts without skins. The fourth diet contained no peanut product and served as the control group.

After the hamsters had been on the test diets for six months, the researchers tested their blood lipid chemistry. Compared to hamsters in the no-peanut control group, those in each of the three peanut groups were found to have significantly lower total cholesterol and LDL "bad" cholesterol. Also positive, HDL "good" cholesterol levels held steady.

Other blood chemistry research has been published that links reduced heart disease risk factors in humans with consuming peanut butter and peanut oil, but this is the first animal study to exhibit such an effect from consuming the fat-free portion of peanuts. While it is still unknown if the effect would translate to humans, the unit’s confirmatory and additional research studies with peanut components are ongoing.

The study was conducted by Tim Sanders, who heads the ARS Market Quality and Handling Research Unit, in Raleigh, N.C., and Amanda Stephens, a food science and nutrition graduate student at North Carolina State University (NC State), in Raleigh.

Stephens is participating in a cooperative program with ARS in which students gain course credit through laboratory training and experience. The ARS study was conducted in NC State facilities under an Institutional Animal Care and Use Committee approved protocol.

ARS is a scientific research agency of the U.S. Department of Agriculture.

Supporting Small Farm Success with Shiitakes

Shiitake (Lentinula edodes) mushrooms are good for you--and shiitake byproducts can be good for other crops.

These mushrooms contain high-molecular-weight polysaccharides (HMWP), which some studies suggest may improve human immune function. Other research indicates that the shiitake compound eritadenine may help lower cholesterol levels.

Agricultural Research Service (ARS) agronomist David Brauer has been studying shiitake production at the agency's Dale Bumpers Small Farm Research Center, Booneville, Ark. Working in collaboration with producers at the Shiitake Mushroom Center in Shirley, Ark., Brauer evaluated whether shiitakes grown on logs have higher levels of HMWP than shiitakes grown on commercial substrates.

The group inoculated logs with spores from three different shiitake varieties and compared the yield with shiitake yields grown on commercial substrates. They found that the log-grown shiitakes had HMWP levels as much as 70 percent higher than the substrate-grown shiitakes. The team also observed that shiitakes grown on red and white oak logs had higher levels of HMWP than shiitakes grown on sweet gum logs.

Logs used in shiitake production generally provide good yields for around two to three years. Larger shiitake farms may have 3,000 or more logs on the premises, and retire around 1,000 of them every year.

Not to let those used logs go to waste, Brauer’s team chipped a selection of spent logs, added urea and green grass cuttings to the chips and then composted the mixture. They found that the nitrogen levels in the resulting compost were comparable to nitrogen levels in other purchased soil amendment materials.

The researchers used the log compost to amend soil in a greenhouse spinach production system and found that the seedlings exhibited greater growth rates than seedlings cultivated in soil that had not been amended. Using recycled log compost provides another way for shiitake mushroom growers to increase their profits.

In 2004-2005, producers harvested approximately 9 million pounds of shiitake mushrooms, which sold for an average price of $3.21 per pound. Brauer’s findings lend a range of support to farmers interested in starting--or boosting profits from--log-grown shiitake production.

ARS is a scientific research agency of the U.S. Department of Agriculture.

Tangy, Junior-size Fruit Bars from ARS Process

Flavorful, chewy bars made from apples, pears and other fresh fruit now come in a size perfect for kids--or for adults who want a healthy, smaller-than-usual snack.

Agricultural Research Service (ARS) scientists developed the process for making the all-fruit bars, which weigh in at just under an ounce (25 grams) and provide the equivalent of about one serving of fruit.

The slim, go-anywhere packaging keeps the bars soft and fresh, and allows them to fit easily into a child's lunchbox. The bars are a handy size to be taken along as a lightweight snack for a hike, bike ride, or camping or backpacking trip. With a two-year shelf life, the bars also are handy for keeping with other foods stored for emergency use in the car or at home.

The junior-sized treats are the newest addition to the line of all-natural fruit bars made by Gorge Delights, Inc., of North Bonneville, Wash. The company holds a license from ARS for the technology used to create the bars from purees and concentrates, without the need for fillers, preservatives or other artificial ingredients.

ARS food technologist and research leader Tara H. McHugh and former ARS agricultural engineer Charles C. Huxsoll, now retired, developed and patented the process. They did the work in their laboratories at the agency's Western Regional Research Center in Albany, Calif.

Gorge Delights introduced the smaller-size bars earlier this year and is marketing them--to vending machine suppliers--in six flavors: apple, apple-cherry, apple-raspberry, pear, pear-cranberry and pear-strawberry.

The company's standard-size fruit bars, each 1.4 ounces (40 grams), are available in those flavors, plus apple-blueberry and pear-blueberry, at retail outlets and on the World Wide Web at www.GorgeDelights.com. All of the bars are gluten-free and kosher-certified.

ARS is a scientific research agency of the U.S. Department of Agriculture.

Glomalin is Key to Locking up Soil Carbon

A soil constituent known as glomalin provides a secure vault for the world's soil carbon. That’s according to Kristine Nichols, a microbiologist at the Agricultural Research Service (ARS) Northern Great Plains Research Laboratory in Mandan, N.D.

Glomalin is a sticky substance secreted by threadlike fungal structures called hyphae that funnel nutrients and water to plant roots. Glomalin acts like little globs of chewing gum on strings or strands of plant roots and the fungal hyphae. Into this sticky “string bag” fall the sand, silt and clay particles that make up soil, along with plant debris and other carbon-containing organic matter. The sand, silt and clay stick to the glomalin, starting aggregate formation, a major step in soil creation.

On the surface of soil aggregates, glomalin forms a lattice-like waxy coating to keep water from flowing rapidly into the aggregate and washing away everything, including the carbon. As the builder of the formation “bag” for soil, glomalin is vital globally to soil building, productivity and sustainability, as well as to carbon storage.

Nichols uses glomalin measurements to gauge which farming or rangeland practices work best for storing carbon. Since glomalin levels can reflect how much carbon each practice is storing, they could be used in conjunction with carbon credit trading programs.

In studies on cropland, Nichols has found that both tilling and leaving land idle—as is common in arid regions—lower glomalin levels by destroying living hyphal fungal networks. The networks need live roots and do better in undisturbed soil.

When glomalin binds with iron or other heavy metals, it can keep carbon from decomposing for up to 100 years. Even without heavy metals, glomalin stores carbon in the inner recesses of soil particles where only slow-acting microbes live. This carbon in organic matter is also saved, like a slow-release fertilizer, for later use by plants and hyphae.

Nichols began her career with ARS working with soil scientist Sara Wright, who first discovered and named glomalin in 1996. Wright has since retired.

Nichols will present these research results this afternoon at a public field day in Brookings, S.D.

ARS is a scientific research agency of the U.S. Department of Agriculture.