Tomatoes chock full of beta-carotene may soon be available to consumers, thanks to the recent ARS release of three new tomato breeding lines. The new lines contain about 10 to 25 times more beta-carotene than typical tomatoes. ARS researchers developed the new lines—97L63, 97L66 and 97L97—for processing into paste, juices and sauces. Soon, ARS will also release high beta-carotene cherry tomatoes and beefsteak-type tomatoes as specialty varieties for the fresh market. The new tomatoes are good nutritional news for consumers, because the human body converts beta-carotene into vitamin A, an essential nutrient that aids in clear vision, bone growth, tooth development and reproduction. Beta-carotene content averages 57.6, 55.1 and 55.5 micrograms per gram of fresh weight for 97L63, 97L66 and 97L97, respectively. Typical tomatoes contain only about 2 to 5 micrograms per gram. Lines 97L63 and 97L66 are adapted for California and the Eastern and Midwestern U.S. These fruits are firm and crack resistant. Tomatoes that split before harvesting are susceptible to fruit rot, which can cause large crop losses. Breeding line 97L97 is adapted for Eastern and Midwestern states. The United States is number two in fresh and processed tomato production worldwide, with Florida and California the top-producing states.
Vegetable Laboratory, Beltsville, MD
John Stommel, (301) 504-5583, jstommel@asrr.arsusda.gov

Blueberries score highest among 50 fruits and vegetables in their ability to defuse damaging oxygen free radicals in a test tube assay. Early studies with rats suggest this antioxidant power translates to protection of cells and tissues. Now the researchers have found a three-fold difference in blueberries' antioxidant ability, depending on species and maturity at harvest. Using the ORAC assay for total antioxidant capacity, they analyzed commercial blueberry varieties and less common species from the United States and Canada. They also analyzed the closely related bilberry from Germany. Overall, the bilberry scored highest in antioxidant capacity. Lowbush blueberries from Nova Scotia and some other U.S. cultivars were quite close to the bilberry in antioxidant capacity, depending upon stage of maturity. Mature berries from two commercial rabbiteye cultivars—Brightwell and Tifblue—scored one and one-half to more than twice as high as berries picked 7 weeks earlier from the same bush. That's due to the increase in antioxidant pigments, or anthocyanins, as the berries mature. Ripe berries not only taste better; they may be more healthful. Region, however, did not affect the antioxidant score, based on analyses of berries from the northern highbush variety, Jersey, grown in Oregon, Michigan and New Jersey.
USDA Human Nutrition Research Center on Aging at Tufts, Boston, MA
Ronald L. Prior/Guohua Cao, (617) 556-3310, prior_us@hnrc.tufts.edu/cao_am@hnrc.tufts.edu.

A new USDA database to be launched on the World Wide Web in 1999 will help scientists pinpoint which estrogen-like compounds in soy foods are responsible for the lower risk of cancer in women—especially breast cancer. And it will enable nutritionists and physicians to recommend the foods with the highest levels of specific estrogen-like compounds, which have also been reported to improve cardiovascular health and reduce bone loss after menopause. Compiled by ARS scientists, the database will give values for the major isoflavones in 140 soy foods and ingredients. Soy isoflavones, such as daidzein, genistein and glycitein, mimic the hormone estrogen. They also have antioxidant capability and may perform other functions that enhance health. The new soy isoflavone database will be on the same web site as the USDA Food Composition Database at http://www.nal.usda.gov/fnic/foodcomp/. While isoflavone values won't be given for individual brand names, commercial products were analyzed to arrive at average values for each type of food or food additive. ARS researchers evaluated and compiled some 30 scientific reports of the isoflavone content of foods. They also relied heavily on analyses done in the laboratory of a collaborator at Iowa State University in Ames to fill in missing or sparse values.
Beltsville Human Nutrition Research Center, Beltsville, MD
Gary Beecher, (301) 504-8356, beecher@bhnrc.usda.gov.

Oatrim reduced oxidation of fatty acids in a recent study that turned up more potential benefits of this ARS-patented fat replacer made from soluble oat fiber. A daily intake of about 1/2 cup of the powdery substance added to various foods reduced an indicator of fat oxidation by 80 percent. This means Oatrim helps protect cell membranes and many other components fabricated largely from fatty acids. And, judging from an increase in the volunteers' breath hydrogen, some of the oat extract was fermented by bacteria in the volunteers' colons, producing short-chain fatty acids. These are thought to protect against cancer and reduce the risk of heart disease. The same researchers earlier reported that a daily diet containing Oatrim reduced body weight and blood lipids, and improved glucose tolerance in men and women participating in the studies. It also reduced systolic blood pressure in the men. The fat substitute is in some baked goods and cheeses as Oatrim or hydrolyzed oat flour. It is also in East Coast markets as an additive for skim milk under the brand name Oatri-Slim. The researchers attribute Oatrim's antioxidant function to something other than its beta glucans—the soluble fibers known to lower cholesterol. That's because fat oxidation dropped about equally whether the volunteers consumed Oatrim with 1 or 10 percent beta glucans.
Beltsville Human Nutrition Research Center, Beltsville, MD
Judith Hallfrisch/Kay Behall, (301) 504-9014, hallfrisch@bhnrc.arsusda.gov/behall@bhnrc.arsusda.gov.

Higher blood levels of a hormone called leptin is one possible reason why African-American teenage girls tend to be heavier and taller and to mature faster than their peers in other ethnic groups, a pediatric researcher has found. Manufactured only in fat tissue, leptin circulates in the blood, where scientists know that it acts as a biochemical curb on appetite. Its counterpart, neuropeptide-Y, is known to trigger hunger. If an individual has higher blood levels of leptin, it may mean the body requires more leptin to "hear" its biochemical message. Other medical research has suggested higher leptin levels may also speed sexual maturity and make the body better at conserving energy. This naturally higher energy efficiency could explain why African-American girls grow faster than their peers from other ethnic groups. But that same metabolic efficiency could backfire in adulthood, contributing to obesity and increased health risk. The ARS-funded research adds to the evidence that all girls can benefit from establishing healthy dietary and physical activity in childhood. The study was published in the October 1998 issue of the Journal of Clinical Endocrinology and Metabolism. The data helps fill in needed information on human metabolism in the African-American population.
Children's Nutrition Research Center at Baylor College of Medicine, Houston, TX
William W. Wong, (719) 798-7168, wwong@bcm.tmc.edu.

Prolina, a high-protein soybean from ARS, appears to have the right amino acid mix to make soy infant formula more like mother's milk. The new bean has an unusually high concentration of cystine, an amino acid that occurs naturally in human breast milk. Prolina has several times more cystine than regular soybean varieties. Scientists have speculated that cystine is important to brain and eye development, because the body uses this amino acid to make taurine, a compound highly concentrated in those organs. As a bonus, Prolina is rich in 11S and 7S proteins that belong to a special class of proteins with enhanced processing properties. This means it's easier to process these beans into a gel form for a fat-free whipped cream made from soy—or to blend them into a liquid emulsion like infant formula. ARS scientists originally bred Prolina as a feed for livestock.
Soybean and Nitrogen Fixation Laboratory, Raleigh, NC
Prachuab Kwanyuen, (919) 515-2734, prachuab_kwanyuen@ncsu.edu