Two more Hawaiian packing houses now use a tactic developed by ARS and the University of Hawaii to ensure that crop-destroying fruit flies won't hitchhike to the U.S. inside papaya shipments. The two packing houses are Hawaii Fruit Growers, a cooperative on the island of Molokai, and Dole Food Company Hawaii on the island of Oahu. Sunrise Packers, Kauai, has used the technology since 1993. The approach requires loading papayas into a steel chamber, then heating the fruit to 117 o F over a period of at least 4 hours. Then, the fruit is cooled for about an hour. ARS experiments with more than a quarter-million fresh papaya and more than one million fruit flies proved that the technique kills Mediterranean and oriental fruit flies and melon flies that might hide inside the sweet, juicy papayas. The process helps prevent the spread of these insects to mainland U.S. orchards, fields and backyard gardens. ARS registered the technology with the U.S. Patent and Trademark Office in 1990. The University of Hawaii is seeking a patent for hot-forced air equipment.
Tropical Fruit, Vegetable and Ornamental Crops Research Laboratory, Hilo, HI
John W. Armstrong, (808) 959-9138, jwa@aloha.net

Budget-conscious consumers may someday be able to enjoy tender, tasty and affordable abalone. For that, they can thank the papaya--and food scientists. Favored blue abalones (Haliotis fulgens) today sell for about $50 a can on the West Coast. They have a savory reputation and a tender, yet firm, texture. In a cooperative project, ARS and University of Georgia scientists used a food- grade enzyme to tenderize the blue's tough cousin, H. cracherodii, black abalone. The tougher black abalone currently sells for only about $10 a can and is marketed mainly in Mexico. The scientists knew that papain, an enzyme derived from papaya, would break down collagen in abalone tissue. But they needed to determine how much papain was needed to tenderize black abalones without damaging flavor. With a texture analyzer--a sort of mechanical "chewer"--they calculated the relative difficulty of chewing both types of abalone. They also used a trained taste panel to confirm and refine their texture and flavor findings.
Richard B. Russell Research Center, Athens, GA
Brenda Lyon, (706) 546-3584, bglyon@athens.net
University of Georgia, Department of Food Science and Technology
Yao-wen Huang, (706) 542-1092, yhuang@uga.cc.uga.edu

A new commercial test uses custom-tailored molecules developed by ARS scientists to detect E. coli 0157:H7 and other disease-causing strains of this bacterium in meat and other food products. The molecules are monoclonal antibodies. Highly specific and sensitive, the improved antibodies make the test capable of readily detecting a single bacterium in a food sample as small as 1 gram, incubated overnight. Until now, quick commercial tests used less specific antibodies that detected all E. coli 0157 serotypes--nonpathogenic, as well as pathogenic--plus a subgroup of other bacteria. Specificity can be critical in testing meat and other food products. Incorrect reports that pathogens are present can alarm consumers and have significant financial impacts on companies.
U.S. Meat Animal Research Center, Clay Center, NE
William W. Laegreid, (402) 762-4177

Scientists have begun a nationwide bacteria hunt to learn where chicken pathogens, such as Salmonella and Campylobacter, might get their start on farms. This could lead to improved methods for stopping pathogens before they can reach consumers. Five top poultry producers have invited ARS scientists to comb their farms in this project, the largest of its kind in the U.S. The year-long study will sample poultry farms in Arkansas, California Georgia, Mississippi and the Delmarva peninsula of Delaware, Maryland and Virginia. Researchers will focus on 10 broiler production farms. They will use genetic tests to identify bacteria they collect at about 25 sites on each farm. Collection sites will include feed bins, insects, hatcheries, farm pets --even farmers' bootsoles. The information will help researchers identify farm areas where additional control may be needed to prevent poultry from being contaminated by pathogens.
Richard B. Russell Research Center, Athens, GA
Norman Stern, (706) 546-3516, nstern@ars.usda.gov

For the first time, a computer model attempts to simulate every step in poultry production to check for potential microbial contamination. ARS scientists developed S-RAMP (Salmonella Risk Assessment Modeling Program) to gauge each poultry-processing stage for three factors: contamination (the presence of disease-causing microorganisms), reduction (the effectiveness of control measures against the microorganisms) and growth (the rate at which microorganisms take hold and grow.) The program predicts numbers of Salmonella organisms that might be present on the meat. This class of software has become crucial to meat producers in the wake of USDA's Hazard Analysis and Critical Control Points program. The HACCP regulation, which took effect in 1996, requires all poultry processors to identify potential contamination sites and take steps to reduce risk.
Microbial Food Safety Research Unit, Princess Anne, MD
Thomas Oscar, (410) 651-6062, toscar@umes- bird.umd.edu

A new laboratory growth medium simplifies food safety research by making bacteria, such as Salmonella, boost their output of proteins and carbohydrates associated with illness from poultry contamination. Growing pathogenic bacterium on this medium causes nearly a 10-fold increase in production of the harmful proteins, making their detection easier. The medium even works on strains that normally don't make these proteins. This means the medium could expose a potentially dangerous side of bacteria previously considered harmless. ARS researchers are seeking new ways to use the medium. For example, scientists interested in developing new vaccines might use the medium to "mine" potentially valuable but hard-to-find proteins from bacterial cells. The medium may also have uses in improving existing vaccines, especially those using killed bacteria. A drug company lab could use the medium to aid evaluations of a protein's quality before harvesting it from a candidate bacterium. This would help ensure consistency from one drug batch to the next.
Southeast Poultry Research Laboratory, Athens, GA
J. G. Petter, (706) 546-3446, jgpetter@uga.cc.uga.edu

Last Updated: February 18, 1998
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