Fuji apples retain flavor and crispness for up to nine months after harvest, thanks to ARS fruit storage methods now used by the apple industry. Previously, Fuji apples were only available to consumers during the fall harvest. No one knew how to keep them fresh for a lengthy market period. However, over six growing seasons, ARS scientists determined how Fuji responds to what's called controlled atmosphere (CA) conditions. CA is a common industry technique used to extend storage life for other varieties of apples by modifying the concentration of the main gasses naturally present in air--oxygen, nitrogen, and carbon dioxide. Scientists analyzed the Fuji for changes in color, firmness, starch, sugar and acid content. Results: the best CA treatment for Fuji apples holds storage temperature at 34 degrees F. and maintains oxygen at one to 1.5 percent and carbon dioxide at one percent or less (Fujis are sensitive to this gas). Fuji apple production is rapidly expanding in Washington state. In 1992, growers there produced about 805,000 boxes of Fujis. By 1995, production had jumped to nearly 3.5 million boxes.
Tree Fruit Research Laboratory, Wenatchee, WA
James P. Mattheis, (509) 664-2280

Some people may suffer chronic joint diseases, such as reactive arthritis, after being infected with bacterial food poisoning. ARS research has shown infections from four common foodborne pathogens--Campylobacter,Salmonella, Shigella, or Yersinia--can lead to reactive arthritis. A tell-tale sign: In reactive arthritis, the foodborne organisms can't be found in joints, but antigenic components of the infecting bacteria are there. People who have the gene for producing the human leucocyte antigen HLA-B27 are more susceptible to arthritis. While only about 2 percent of people who get food poisoning develop arthritis, about 20 percent of those exposed who carry the HLA-B27 gene get it. This gene is found in about 10 percent of healthy Caucasians, one percent of Japanese, and up to four percent of North American blacks, but is absent from African and Australian blacks. Foods that carry the four common bacteria include raw and undercooked meat, poultry, eggs, shellfish and other seafood, unpasteurized milk, fruit, and vegetables. Untreated drinking water and household pets are also sources.
Microbial Food Safety Research Unit, Eastern Regional Research Center, Wyndmoor, PA
James L. Smith, fax (215) 233-6568, jsmith@arserrc.gov

Harmless yeasts may help thwart toxin-making fungi from infecting pistachios, walnuts and other tree nuts, according to ARS scientists. And, to safeguard people and animals, USDA monitors and sharply limits aflatoxin levels in feed and food products. The principal toxin-making fungi are Aspergillus flavus and A. parasiticus. They can infect peanuts, grains such as corn, cottonseed, and tree nuts like walnuts and pistachios. Damaged or broken grain kernels or nuts are the most susceptible to fungal attack. In ARS tests, several strains of Candida sp. yeast reduced the number of A. flavus spores on artificially infected pistachios by at least 50 percent. The yeasts out-compete the fungi for nutrients, and produce chemicals that inhibit fungal growth. Yeasts are good candidates for biological control, becuse they are easy to grow and can live a long time on dry surfaces such as nutshells without harming the nut itself. Next, scientists will conduct larger tests on several types of nuts. They're also experimenting with best methods for applying the yeasts to nuts.
Plant Protection Research Unit, Albany, CA
Sui-Sheng Hua, (510) 559-5905

Hot summer days can mean better bread for consumers. Researchers discovered that hard red wheat exposed to the right number of 90-degree-plus days makes a better loaf of bread. Armed with this information, commercial millers and bakers might shop for wheat grown in areas with just the right amount of sun-baked weather. But it is possible to get too much of a good thing: Too many high-heat days can cause a breakdown of the gluten protein structure in the wheat kernel, resulting in poor-quality flour and lower-quality bread. Gluten protein imparts to wheat its unique ability to function in leavened bakery products.
Wheat, Sorghum and Forage Research, Lincoln, NE
Bob Graybosch, (402) 472-1563

Consumers, confectioners and fruit growers could benefit from novel fruit products developed by ARS scientists. In experiments, researchers made molded, restructured fruit pieces containing up to 30 percent apricot or peach puree. Another method, twin-screw extrusion, produced licorice-like ropes containing up to 100 percent fruit. Many commercial snacks containing fruit include much more sugar than these pieces and use less than five percent juice or puree. The higher fruit content of the ARS products could make them a healthier addition to confections and baked goods. Restructured fruit products could also expand the market for soft fruits that can be pureed during the growing season and used by manufacturers year-round. New combinations of starch and gelatin allow the puree to be custom-manufactured into a wide range of products.
Process Chemistry and Engineering Research, Albany, CA
Tara McHugh, (510) 559-5864

Whole-wheat bread made from hard white wheat may become more appealing to American consumers. That's because researchers are working to breed white wheat that contains less amylose starch. Reducing amylose boosts palatability of bread and may extend its shelf life. Hard white wheat also could give American wheat growers a better shot at the burgeoning Oriental noodle market here and abroad. Asians prefer white wheat's lighter color and chewier mouth feel. Researchers are looking for ways to grow hard white wheat varieties with just the right qualities to make Oriental noodles and some types of low-cholesterol whole wheat breads.
Wheat, Sorghum and Forage Research, Lincoln, NE
Jim Peterson, (402) 472-5191

Maintaining and improving the quality of fresh-cut produce is a major challenge in the fast-growing market for fresh fruits and vegetables. A chlorine solution now used by industry to control microorganism growth isn't always effective. In a joint study with Japanese scientists, ARS researchers reduced microorganism growth on cut carrots without altering firmness by dipping the carrots in a calcium chloride solution. The calcium chloride treatment also worked well on zucchini squash, which is highly perishable and very sensitive to cold temperatures. The ARS study also showed fresh-cut produce should be handled and stored at or near 32 degrees F if the product is not sensitive to chilling injury. Many processors prepare, ship and store fresh-cuts at 4l degrees or even 50 degrees F. Sales of fresh-cut produce in the United States are projected to increase from $5.8 billion in 1994 to $19 billion in 1999.
Horticultural Crops Quality Laboratory, Beltsville, MD
Alley E. Watada, (301) 504-6128

Last Updated: January 28, 1997
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