Page Banner

United States Department of Agriculture

Agricultural Research Service

Food and Nutrition Research Briefs, July 2014

Table place setting with apple. Title: Food and Nutrition Research Briefs. Link to FNRB home page

July 2014


FNRB Index | Search | Comments


 

Contents

Effect of Mom's Obesity on Baby's Bone Health Explored

Making White Layer Cakes with More Fiber, Less Fat

Tactic for Pasteurizing Raw Eggs Kills Salmonella, Doesn't Harm Egg Quality

Heat and Pressure Treatment May Affect Allergenic Proteins in Peanuts

Botulism-causing Toxins Detected Promptly by ARS-developed Test Strip

Pampering Anjou Pears: ARS Studies Explore Storage Ideas

Dietary Products: Some are Under-researched, Over-marketed

Flavor Secrets of Hass Avocados Probed

Specialty Greens Pack a Nutritional Punch

Puree-processing Technology Expands into New Markets

Sesame Seed Oil Extract May Improve Soy Oil for Frying  

Effect of Mom's Obesity on Baby's Bone Health Explored

In an early investigation, it was found that bone development of the unborn young of mother lab rats (dams) fed high-fat rations to induce obesity was significantly impaired, in contrast to the bones of the fetal young of dams that were given lower-fat rations. Analysis of fetal bone cells suggests that changes in the functioning of the gene HoxA10 may help explain this difference in early bone formation. This investigation is apparently the first to suggest that obesity, induced by the high-fat regimen, may turn off or "downregulate" this gene, thus suppressing robust bone development. HoxA10 was downregulated as a result of high levels of DNA methylation, a biochemical process also referred to as gene methylation.

Details

For details, contact Jin-Ran Chen, (501) 364-2707, Skeletal Development Laboratory, ARS Arkansas Children's Nutrition Center, Little Rock, Ark.

Photo: Researcher Jin-Ran Chen uses a next-generation DNA sequencer to investigate changes in gene methylation. Link to photo information
Researcher Jin-Ran Chen uses a next-generation DNA sequencer to investigate changes in gene methylation.

Back to Contents


Photo: A carton of eggs. Link to photo information
Agricultural Research Service and Princeton University scientists used radio frequency heating to develop a better way to pasteurize eggs.

Tactic for Pasteurizing Raw Eggs Kills Salmonella, Doesn't Harm Egg Quality

Agricultural Research Service (ARS)-led research has produced a faster way to pasteurize raw, in-shell eggs without ruining their taste, texture, color or other important qualities. The pasteurization process, currently in the prototype stage, killed 99.999 percent of the Salmonella injected into raw in-shell eggs in tests. When commercialized, the new 20-minute pasteurization procedure would provide an alternative to the hour-long hot-water-immersion process, which is apparently the only one already used commercially in the United States to pasteurize fresh shell eggs. The new procedure begins with positioning each raw egg between two electrodes that send radio waves back and forth through it. The egg is slowly rotated and sprayed with water to offset some of the heat created by the radio waves. Unlike conventional heating, the radio-frequency (RF) heating warms the egg from the inside out, enabling the dense, heat-tolerant yolk at the center of the egg to receive more heat than the delicate, heat-sensitive egg white. A comparatively brief hot-water bath comes next. The warmth of the bath helps the yolk retain heat to complete the pasteurization. The bath also pasteurizes the egg white without overprocessing it. Using RF heating to kill pathogens in eggs apparently is novel.

Details

For details, contact David J. Geveke, (215) 233-6507, Food Safety and Intervention Technologies Unit, ARS Eastern Regional Research Center, Wyndmoor, Penn.

Back to Contents


Botulism-causing Toxins Detected Promptly by ARS-developed Test Strip

A handy test strip has been developed by Agricultural Research Service (ARS) scientists that may give food safety and homeland security officials a powerful tool to use to identify botulism-causing toxins. As the basis of a field-ready test kit, the strip can provide results in less than 20 minutes, providing rapid, preliminary screening in an outbreak of foodborne botulism in which the culprit food has not yet been pinpointed or during other emergencies. Only a small amount of prepared sample is needed for this kit, which is likely the first that can concurrently detect and differentiate between the A- or B-type (serotype) botulinum toxins. Together, these types are responsible for more than 80 percent of all cases of foodborne botulism in the United States.

Details

For details, contact Robert Hnasko, (510) 559-5878, Produce Safety and Microbiology Research Unit, ARS Western Regional Research Center, Albany, Calif.

Photo: A lateral flow device containing a test strip that can identify botulinum toxin in less than 20 minutes. Link to photo information
An ARS-developed test strip can be used in a field-ready kit to detect botulism-causing toxins in less than 20 minutes.

Back to Contents


Photo: Chemist Pei Chen prepares extracts from dietary supplements to study differences in phytochemicals. Link to photo information
Chemist Pei Chen prepares extracts from dietary supplements to study differences in phytochemicals.

Dietary Products: Some are Under-researched, Over-marketed

Agricultural Research Service (ARS) scientists have studied African mango (AM) supplements and found that none of the labels on the ones they tested provided accurate information for consumers. All of the labels of African mango dietary supplement products sold in the United States list African mango seed extract as the major ingredient. The team obtained AM seeds imported directly from Africa that came with a voucher verifying authenticity and were further authenticated by U.S. Pharmacopeia, three AM seed extracts, and five different AM dietary supplements to analyze. During testing, they identified a group of major components in the verified AM seeds: ellagic acid; mono-, di-, and tri-O-methyl-ellagic acids; and their related glycosides. These components were used as authentication markers when testing the contents of AM extracts and related AM dietary supplements for quality control. Among the five AM dietary supplements tested, only one contained trace amounts of AM seed. The other four supplements and the three AM seed extract samples did not contain any detectable amount of authentic AM seed.

Details

For details, contact Pei Chen, (301) 504-8144, ext. 238, Food Composition and Methods Development Laboratory, ARS Beltsville Human Nutrition Research Center, Beltsville, Md.

Back to Contents


Specialty Greens Pack a Nutritional Punch

A team of Agricultural Research Service (ARS) scientists has analyzed the key nutrients in 25 different varieties of vegetable microgreens. The team showed that different microgreens contained widely differing amounts of vitamins and carotenoids. Total vitamin C content ranged from 20 to 147 milligrams (mg) per 100 grams of cotyledon fresh weight, depending on which plant species was being tested. The amounts of the carotenoids beta-carotene, lutein/zeaxanthin, and violaxanthin ranged from about 0.6 mg to 12.1 mg per 100 grams of fresh weight. For comparison, an average apple weighs 100 to 150 grams. In general, microgreens contained considerably higher levels of vitamins and carotenoids—about five times greater—than their mature plant counterparts. Among the 25 microgreens tested, red cabbage, cilantro, garnet amaranth, and green daikon radish had the highest concentrations of vitamin C, carotenoids, vitamin K and vitamin E, respectively. Growing, harvesting, and handling conditions may have a considerable effect on nutrient content.

Details

For details, contact Yaguang Luo, (301) 504-6186, Food Quality Laboratory, ARS Henry A. Wallace Beltsville Agricultural Research Center, Beltsville, Md.

Photo: Red cabbage microgreens. Link to photo information
ARS scientists analyzed key nutrients in 25 different varieties of microgreens and found that red cabbage microgreens (shown here) had the highest concentrations of vitamin C.

Back to Contents


Photo: French fries in a deep-fryer. Link to photo information
Adding sesamol—an extract from sesame seed oil—could help protect the soybean oil's polyunsaturated fats from oxidation.

Sesame Seed Oil Extract May Improve Soy Oil for Frying

Agricultural Research Service (ARS) scientists are investigating interesting natural antioxidant compounds that might effectively and affordably protect soybean oil from oxidation during frying. In preliminary experiments, they found that sesamol, extracted from sesame seed oil, provided better antioxidant protection for soy oil than nine other natural antioxidants that the team tested. Importantly, the team's tests with french fries showed that sesamol, when added to soy oil at the rate of 6,600 parts per million, provided better protection than TBHQ, a synthetic antioxidant, added at the allowable maximum of 200 parts per million. They caution that even though sesamol is a natural, edible compound, more research is needed to ensure that using it at levels that provide antioxidant protection for the soybean oil would meet federal GRAS (Generally Recognized As Safe) standards.

Details

For details, contact Hongsik Hwang, (309) 681-6584, Functional Foods Research Unit, ARS National Center for Agricultural Utilization Research, Peoria, Ill.

Back to Contents


Making White Layer Cakes with More Fiber, Less Fat

White layer cakes can be made with more fiber or less fat without significantly undermining many of the qualities of this favorite treat, according to Agricultural Research Service (ARS) scientists. These improvements can be made to cakes that are prepared at commercial bakeries or to boxed mixes sold for home bakers. Purified, finely ground corn bran can be used as a substitute for up to 20 percent of the flour called for in the American Association of Cereal Chemists' "gold standard" test recipe for white cake, and not significantly impact qualities such as color or springiness (the unfrosted top surface of a good cake will spring back when gently touched). The 25 volunteer taste-tasters who sampled cake made with that amount of the fiber rated it as "acceptable." In taste-tester terminology, that counts as a vote of confidence. One slice of an 8-inch, 6-slice, two-layer white cake made with 20 percent corn bran fiber would provide about 5 grams of fiber, compared to about 1 gram from a conventional white layer cake.

Details

For details, contact Mukti Singh, (309) 681-6357, Functional Foods Research Unit, ARS National Center for Agricultural Utilization Research, Peoria, Ill.

Photo: A slice of cake on a plate. Link to photo information
ARS scientists have found a way to increase the fiber content of white layer cake and cake mix—without significantly impairing quality—by replacing some of the flour with finely ground corn bran.

Back to Contents


Photo: A pile of shelled peanuts. Link to photo information
Treating peanuts with moist heat and pressure, a process called autoclaving, significantly reduced the allergenicity of the peanuts' proteins.

Heat and Pressure Treatment May Affect Allergenic Proteins in Peanuts

Agricultural Research Service (ARS) scientists and their colleagues found that when they applied heat and pressure to roasted peanuts, there was a significantly reduced allergic reaction from the proteins in these peanuts. Previously, it had been found that while people generally eat peanuts that have been roasted or boiled, the extracts that are commonly used to diagnose peanut allergies are from raw peanuts. Also, it had been shown that side reactions induced by roasting, such as browning the peanuts, increased the amount of antibody that recognizes and binds to major allergenic proteins (allergens), when compared to the amount that binds to allergens from raw peanuts. The process the researchers used to apply heat and pressure is called autoclaving. It involves a higher moisture environment—similar to steaming or boiling—than roasting. As a result, autoclaving does not initiate the browning effect that comes with roasting.

Details

For details, contact Soheila Maleki, (504) 286-4590, ARS Food Processing and Sensory Quality Research Unit, New Orleans, La.

Back to Contents


Pampering Anjou Pears: ARS Studies Explore Storage Ideas

Research suggests that tactics that work well for keeping fresh apples free of plant diseases or other disorders while in controlled-atmosphere storage may not necessarily be applicable to Anjou pears. Chlorophyll fluorescence monitoring, which is used successfully to detect problems in stored apples, was tested as a candidate "early warning system" for stored pears. That's because an increase in the fluorescence levels in the chlorophyll in a stored apple's peel apparently correlates well with an increase in problems linked to low oxygen levels. When apple chlorophyll levels go up during storage, storehouse managers know to raise the oxygen level slightly to prevent damage to the fruit. But the monitoring system didn't work well in detecting either black speck or pithy brown core in Anjou pears that were stored experimentally in extremely low oxygen conditions. Black speck and pithy brown core occurred despite the fact that there were no detectable changes in the affected pears' chlorophyll fluorescence levels. For that reason, packers are being advised, at least for now, to use caution before relying on chlorophyll fluorescence for monitoring stored Anjou pears in very low oxygen conditions.

Details

For details, contact James P. Mattheis, (509) 664-2280, ARS Physiology and Pathology of Tree Fruits Research Laboratory, Wenatchee, Wash.

Photo: Anjou pears growing on a tree. Link to photo information
Anjou pears don't ripen on the tree. Instead, commercially grown Anjous are ripened and stored indoors.

Back to Contents


Photo: A halved avocado on a plate. Link to photo information
ARS researchers are identifying key avocado compounds that contribute to ideal flavor and may serve as "markers" that breeders could use to select new avocado varieties.

Flavor Secrets of Hass Avocados Probed

The kinds and concentrations of aroma compounds that are essential to the classic Hass avocado flavor are being determined by Agricultural Research Service (ARS) scientists. These key compounds might one day serve as "markers" that breeders could use in pinpointing the most promising new kinds of avocados. Growers and packers of the future also might be able to use the markers to determine the best times to harvest the fruit, or to develop new tactics that better protect these compounds or their precursors during storage and ripening. These studies are apparently the first to report the levels of aroma compounds during Hass avocado maturation and ripening. Three chemicals prevalent in the early growth of the fruit (hexanal; (E)-2-hexenal; and 2,4-hexadienal) were probably responsible for a grassy flavor, and the "likeability" of the fruit, from the taste testers' point of view, increased as the levels of these compounds decreased in the maturing fruit. This work differs from most prior avocado flavor studies, which primarily focused on the flavor contribution of the fruit's natural oil.

Details

For details, contact David Obenland, (559) 596-2801, ARS San Joaquin Valley Agricultural Sciences Center, Parlier, Calif.

Back to Contents


Photo: Sweetpotato purees being made with continuous-flow microwave technology. Link to photo information
A new puree-making process provides purees for use in a variety of finished food products such as cookies, pies, soups and frozen foods.

Puree-processing Technology Expands into New Markets

A puree-making process has gone international with patents issued in the United States and now also in China, New Zealand and Australia. The award-winning process was jointly patented by collaborators with the Agricultural Research Service (ARS), North Carolina State University in Raleigh, and Industrial Microwave Systems, LLC, in Morrisville, North Carolina. The microwave processing method and a shelf-stable packaging system provide purees used by manufacturers as well as commercial buyers and other customers. The purees are used in a variety of finished food products such as cookies, pies, ice cream, baby foods, soups, beverages and frozen foods. Originally licensed for making and packaging nutritious sweetpotato puree, the unique process is now being used to make pumpkin, butternut squash, broccoli, carrot and spinach purees. When naturally sweet vegetable purees are used in baked goods as a "replacer," for example, manufacturers can cut back on sugars, fats and oils, which are more expensive and less nutritious. A variety of foodservice operators, restaurants and bakeries also use the purees. Purple-fleshed sweetpotatoes have also been converted into shelf-stable purees for food applications with retained levels of anthocyanins comparable to those in grapes, plums, sweet cherries, eggplant and red radishes.

Details

For details, contact Van-Den Truong, (919) 513-7781, ARS Food Science Research Unit, Raleigh, N.C.

Back to Contents


 

Last Modified: 7/25/2014
Footer Content Back to Top of Page