Increasing the Safety and Shelf Life of Agricultural Commodities

NON-TECHNICAL SUMMARY: Maintaining the expected quality and safety of food and agricultural products could be challenged by chemical and biological contamination. Of particular concern is the threat of food poisoning. To protect the safety of the food supply and to assure continued high quality of agricultural commodities, it is essential to have methods available for predicting the potential contamination of foods and other agricultural commodities. <P>
APPROACH: Develop a model prototype biosensor capable of analyzing for select food poisioning organisms, ie. enterotoxin-producing staphylococci in pure culture. Subsequent goals will be to authenticate the use of the biosensor and develop methods for use of the biosensor for detection of organisms within or on the surface of food and other agricultural commodities, water, air, and food processing equipment.
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PROGRESS: 2002/07 TO 2004/06<BR>
A bioelectronic detector system was developed consisting of a capture and amplification system and analysis with transistor/detectors, digitizing electronics and a microprocessor. A biochemical system was designed to capture target protein, DNA or other biomolecules from microorganisms enabling the one step purification and concentration of the target molecule. Subsequently, signal molecules are generated as a result of the interaction between a biochemically designed signal probe and the target molecule that serves to amplify the signal. The signal generation component can be applied to several organisms or biomolecules. The specificity for each target organism or toxin is based on the development of specific recognition components that bind specifically with the target molecule. The signal molecules are then captured on the surface of the electronic detector through specifically designed biomolecules that are bound to the transistor gate. This system changes electronically when it captures its specific target molecule and the electronic circuitry is capable of recognizing the presence of the signal biomolecules bound on the detection surface. A microelectronic test chip has been specifically designed and manufactured for this purpose. Affinity binding materials and organic conductor and insulator molecules have been evaluated and selected for evaluation via attachment as self-assembled monolayers on a gold surface. Work continues on this project and information can be found in IDA00302-SG and IDA00404-SG. A patent on the detector system was applied for in August, 2004.
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IMPACT: 2002/07 TO 2004/06<BR>

The early, fast and accurate detection of biological pathogens is an important element for ensuring the safety and shelf life of agricultural commodities. Staphylococcal food poisoning is the most common type of food-borne illness in the US and in a typical year, affects 1.5 million Americans, causing $1.2 billion in economic losses. Current technologies for the detection of microbial pathogens are slow in producing a positive diagnosis, can be costly if PCR techniques are employed and require the use of skilled professionals. The technology advanced in this work will produce near real time detection results. Currently many food products must be held in storage an additional time to allow accurate testing for pathogens. With the proposed electronic detection, this time delay can be greatly reduced assuring greater freshness and safety to the consumer and lower cost to the producer. The detector could also be used to follow potential food poisoning outbreaks. Through the use of a microprocessor on-board the detector, information could be directly sent and collected via the internet to the USDA or other federal and state agencies. Such knowledge in a near real time fashion would be extremely valuable in response to emergency situations.