Indian American develops food sensor

If Americans can eat spinach and other food and vegetables again without fearing that Escherichia coli will strike them down, the credit should go to an Indian-American scientist at Drexel University.

Raj Mutharasan, a professor of chemical engineering, has developed a simple hand-held sensor that can quickly detect in food and vegetables the presence of E coli, the bacteria, which can cause serious illness. "It is as easy as using a thermometer that can be used by just about anybody," Mutharasan told rediff India Abroad.

E coli, as it is commonly known, is a leading cause of food-borne illness. Mutharasan quoted a 1999 estimate that said that, on average, E coli infected 73,000 people in the US and killed 61 of them every year.

E coli infection can result in bloody diarrhea, and, occasionally, kidney failure. Though most illness has been associated with eating undercooked, contaminated ground beef, people have also become ill from eating contaminated bean sprouts or fresh leafy vegetables such as lettuce and spinach.

Mutharasan said one advantage with his team's new technology is that, unlike available technology, the sensor quickly detects the presence of the bacteria.

If its presence could be gauged fairly quickly with an inexpensive unit, it was more likely that tests would be done, thereby helping reduce the risk of outbreaks, he said. Currently, a sample is sent to a laboratory, which responds in about a week.

"Whenever things take long, you tend not to do it very often," he said. If measurements could be taken in half an hour companies may do it once every shift, he said arguing that rapid detection would benefit both manufacturers and consumers.

Mutharasan's hand-held E coli sensor is an offshoot of the work he began some four years ago, detecting pathogens like anthrax, thanks to interest expressed by the Department of Homeland Security. "The technology that is used is the same," he said.

He is the Frank A Fletcher Professor of Chemical and Biological Engineering at Drexel University from where he earned his PhD in chemical engineering in 1973. He did his BS, also in chemical engineering, at the Indian Institute of Technology, Madras, in 1969.

The Department of Agriculture has given Mutharasan $527,150 over three years to research toxin and pathogen detection in meat, poultry and liquids like milk and apple juice. Besides, the Environment Protection Agency and the Department of Homeland Security fund him as well.

Mutharasan's technology depends on a vibrating glass beam coated with a substance that binds to E coli cells on its surface. With enough cells sticking to the glass beam, the frequency of its vibration changes, thus providing a measure of the number of E coli in the sample "It [the device] can also look for infections in urine, saliva or blood – or even [detect] prostrate cancer," he said.

Mutharasan completed work on the project about a year ago, but once the details were published in Biosensors and Bioelectronics, a scientific journal, it quickly found its way into the newspapers.

One of the greatest plus points of this technology, he said, is that someday it could enter ordinary homes so that people could screen their food.

"This idea is currently being commercialized by a company which has licensed the technology…. Hopefully, sometime next year it will be available and then things will be a lot easier for people everywhere," he said.