Tuesday, October 26, 2010

A Model for Smoked Salmon Safety

Scientists with the U.S. Department of Agriculture (USDA) have developed a mathematical model providing optimal combinations of temperature, salt and smoke compounds to reduce microbial contamination of smoked salmon.

Typically sold in vacuum packages that have a refrigerator shelf life of about three to eight weeks, smoked salmon can be susceptible to pathogenic microbes such as Listeria monocytogenes can live at refrigerator temperatures.

In their studies, researchers added salt and smoke compounds to cooked salmon, then inoculated the fish with Listeria monocytogenes. Next, the scientists exposed the salmon to a range of temperatures, from 104 degrees Fahrenheit to 131 degrees F to simulate commercial smokehouse processing.

Regarded as mid-range, these temps are higher than those used for cold-smoking, the most popular commercial salmon-smoking process, but are lower than those of the lesser-used commercial hot-smoking procedure.

The researchers determined that every 9 degree F increase in temperature resulted in a 10-fold increase in rates of inactivation of Listeria. They used this and other data from the study to create the mathematical model.

Source: Agricultural Research Service

Sunday, October 3, 2010

100% Fruit Juice Improves Children's Diet

Consumption of 100 percent fruit juice is closely linked to improved nutrient intake and overall diet quality in children and teens, according to researchers at the Louisiana State University Agricultural Center and Baylor College of Medicine

The researchers used data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) to compare the diets of juice drinkers to non-consumers.

According to the findings, children 2-5 years of age who consumed fruit juice had significantly higher intakes of vitamin C, potassium, and magnesium and significantly lower intakes of added sugars compared to non-fruit juice consumers.

In addition, higher intake of fruit juice was directly correlated with increased consumption of whole fruits and whole grains.

Children 6-12 years of age showed a similar positive association between intake of 100 percent juice and higher intakes of the key nutrients, as well as dietary fiber. Overall diet quality, as assessed by the Healthy Eating Index (a measure that evaluates conformance to federal dietary guidance) was higher in all fruit juice consumers assessed.

The researchers reported that a significantly higher percentage of non-fruit juice consumers 2-18 years of age failed to meet the recommended levels for several key nutrients, including vitamins A and C and folate, compared to those who drank 100 percent juice. Comparatively, a greater percentage of those in the fruit juice group exceeded Adequate Intake levels for calcium versus non-consumers.

"One hundred percent fruit juice plays an important role in the diets of children and teens, supplying important nutrients during a key period of growth and development," notes lead researcher Dr. Carol O'Neil. "Drinking 100 percent juice should be encouraged as part of an overall balanced diet."

Source: Juice Products Association

Friday, October 1, 2010

Goodbye Nut Allergies

Johns Hopkins scientists have discovered a way to turn off the immune system's allergic reaction to certain food proteins in mice, a discovery that could have implications for the millions of people who suffer severe reactions to foods, such as peanuts and milk.

The findings, published online in the journal Nature Medicine, provide hope that the body could be trained to tolerate food allergies that lead to roughly 300,000 emergency room visits and 100 to 200 deaths each year.

The research team, led by Shau-Ku Huang, Ph.D.,discovered that one kind of immune cell in the gastrointestinal tract called lamina propria dendriti cells (LPDC) -- considered the first line of defense for a body's immune system -- expresses a special receptor, SIGNR1, which appears on the cells' surface and binds to specific sugars.

By targeting this receptor using sugar-modified protein, researchers were able to keep food proteins that would have induced a severe, even deadly, allergic reaction from causing any serious harm.

"There is no cure for food allergies, and the primary treatment is avoidance of the offending protein," Zhou says. "This could teach our bodies to create a new immune response and we would no longer be allergic to the protein."

The researchers hope to confirm whether this promising process in mice can also occur in people.