Create heart-healthy foods by modifying carbohydrate content.

USDA-ARS scientists are attempting to generate new biologically active carbohydrate compositions from cereals. They intend to create new products with unique properties for the nutraceutical and functional food markets. They plan to develop carbohydrate materials with elevated beta-glucan content that will offer nutritional benefits related to cardiovascular and diabetic diseases.

Some background: Mixed linkage, beta-glucan soluble fiber is found in oat, barley and in small quantities in other cereal grains. It reduces plasma cholesterol levels in humans and may have other healthful properties. High-plasma cholesterol is a risk factor for cardiovascular disease. We can claim health benefits for whole oat products containing beta-glucans related to cardiovascular disease.

Beta-glucans also reduce the postprandial rise of glucose and insulin, suggesting it has a role in diabetes management. However, the physiological properties of cereal beta-glucans depend on their bioavailability and molecular characteristics. ARS studies show that endogenous enzymes and mechanical processes reduce the polymer size of the glucans, but cooking increases their bioavailability. Animal studies indicate that the limited polymer size degradation, which occurs when foods containing glucans are processed, does not affect plasma cholesterol-lowering properties.

The ARS scientists plan to develop innovative processing techniques and will evaluate cereals for levels of beta-glucan. The major objective here is to increase the levels of this bioactive component in different products. The researchers will apply hydrocolloidal aggregative formations to selectively separate bioactive components. Their work also will involve conducting basic research studies to determine the influence of compositions on process variables. They are interested in determining the impact of specific ingredient combinations on starches. They want to develop carbohydrate materials that have increased resistance to enzymatic hydrolysis in the gastrointestinal system.

FYI: ARS scientists have found that people whose diets are highest in carbohydrates actually eat fewer calories per day and are less likely to be obese than people who eat diets with higher levels of fat and protein. This is based on a data analysis of carbohydrate intakes from the USDA's Continuing Survey of Food Intakes by Individuals for the years 1994 through 1996. The analysis showed that those whose diets were highest in carbohydrates not only consumed 200 to 300 fewer calories daily, but they also had diets that were higher in nutrients. The study's results are contrary to some fad diets that emphasize decreasing carbohydrate intake while increasing protein and fat.

Further information. George Inglett, USDA-ARS National Center for Agricultural Utilization Research, Room 2306, 1815 N. University St., Peoria, IL 61604; phone: [phone]; fax: [phone]; email: [e-mail].