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5 Ways Science Is Trying to Keep Your Food Safe
In the wake of the deadly salmonella outbreak, a look at technologies being developed in the lab to protect us against future eruptions
By Andrew Moseman
<!--/end headline--> During the most recent outbreak of salmonella poisoning, which was connected to peanut butter and other peanut products, the food-borne bacteria has sickened nearly 700 people and may have contributed to the death of nine, the U.S. Food and Drug Administration reports. That came on the heels of an outbreak last summer, finally traced back to jalapeño peppers imported from Mexico, that was responsible for more than 1,400 infections, the U.S. Centers for Disease Control reports.
And when deadly pathogens enter the food supply, the financial costs can add up, too. The peanut butter salmonella outbreak caused the recall of thousands of peanut-related products, and Georgia Peanut Commission executive director Don Koehler says the total loss could be more than $1 billion.
So what are researchers doing to protect our food?
Scientists across the U.S. are using genetics, vacuum pressure, plasma, and other measures to try to prevent the disruptions and tragedies caused by an outbreak. Their research is far from complete but could someday make you feel a lot better about that chicken you're eating
CLICK TO ENLARGE + Purdue Agricultural Communication photo/Tom Campbell
<!--/end picture--> 1. Dr. Keener's Ionizing Ozone MachineScientists fingered spinach as the villain in the September to October 2006 outbreak of Escherichia coli, which sickened 205 and killed three. Now Purdue University's Kevin Keener might have a way to rid microbial infections from the leafy green: plasma.
Keener's device uses high-voltage coils to create a room-temperature plasma field inside a food bag, which ionizes the air inside and creates ozone. Exposure to the gas kills microbes after a few minutes, and it dissipates within 24 hours, Keener says. His lab model cost about $1,500 to build, though he says an industrial-size version could fall more in the $15,000 range.
He says the treatment doesn't leave the food smelling funny, and the slight increase in temperature doesn't cook it. Rather, the hitch thus far is discoloration—ozone also kills chlorophyll—so if there's a cut that allows the gas inside the plant it can partially bleach it.
Carl Batt
<!--/end picture--> 2. Microfluid Chip for Pathogen-TesterOne of the biggest food safety challenges of the modern economy, Cornell University's Carl Batt says, is that our food gets shipped around so much. For the past decade, his lab has been working to downsize pathogen-detecting technology into something just as mobile as our food supply.
Batt's machine extracts a liquified sample of the food and uses a microfluid analysis chip to do a DNA-based scan for the pathogen in question (right now, it's salmonella). The current machine is the size of a suitcase, he says, but the device keeps shrinking as the nanotechnology to move the fluids advances. In the photo, student Sushmitha Krishnan holds the chip for an even smaller model. "People want this tricorder, Star Trek kind of stuff," he says.
So will a tricorder soon be scanning your food for salmonella? Don't count on it. Batt says few of the second-generation, briefcase-size machines are even out there yet. Despite occasional food scares, he says, the market for pathogen-hunting hasn't caught up to the technology yet—Batt says the tester probably costs between $30,000 and $50,000 right now
Doug Powell
<!--/end picture--> 3. Blogging... And Spying on YouInspired in part by the recent move of Butterball's call-in Turkey Talk-Line to the Web and health blogs like WebMD, Kansas State University food scientist Doug Powell decided new media was the way to keep people informed about how to keep up on food safety. So he started Barfblog. This compendium of the disgusting stays up-to-date on food scares and bloggers' own stories when they didn't do so well keeping their own food disease-free.
Powell also wanted to see whether people are learning to follow food safety instructions, so he gathered 40 test subjects—half adults, half adolescents—in a model kitchen with food that's been implicated in disease outbreaks, like chicken thighs. Participants did okay—73 percent washed their hands before cooking, but very few checked their chicken with a internal thermometer when they were done.
Anyway, Powell's not alone as media advocate for food safety. If you need a little silly in your day, check out University of California, Davis, professor Carl Winter's food safety song parodies, like "Who Left the Food Out?" and "50 Ways to Eat Your Oysters."
Jerry Heitschmidt, USDA Agricultural Research Service
<!--/end picture--> 4. Finding Cracked EggsCracks in eggs aren't simply an inconvenience for shoppers, they're also a open door for pathogens to enter. Human inspectors do a decent job at crack detection, catching about 86 percent, according to the U.S. Department of Agriculture. But some cracks are too tiny to be seen, and expand later during shipping and sitting in the store. To solve the egg problem, scientists at the USDA's Agricultural Research Service turned to a vacuum.
Putting a batch of eggs into a vacuum creates negative pressure—the insides of the egg want to get out. If the shell is intact, no problem. But if it contains microcracks, the pressure ruptures them further and makes them more visible to inspectors. In the testing system, each egg gets its own LED light, according to project agricultural engineer Kurt Lawrence, and the researchers use a monochrome camera to take before-and-after photos to notice cracks that expand in the vacuum.
Lawrence says the team has yet to develop a commercial model, but tests of the system showed it was 99.4 percent effective at finding cracks.
Susan Lamont
<!--/end picture--> 5. More Resistant Chickens, Fewer OutbreaksRather than rooting out salmonella from chickens entering the food supply, Susan Lamont of Iowa State University is trying to figure out how to make chickens themselves more resistant to the pathogen. For the last eight years her lab has tried to uncover the genetic reasons why some chickens have more resistance to pathogens than others do.
For example, scientists had known for years that some chickens have greater salmonella-resistance, Lamont says. Genetic studies picked up steam five years ago, when the chicken became the first farm species to have its genome sequenced. Since then, Lamont's been breeding chickens with promising biological markers—groups of genes that seem to correlate with salmonella resistance—to produce generations of more resistant chickens. "We can see what is changing over time," she says.
Poultry companies are doing the same thing, she says, but because the results aren't patented, they're loath to let loose any trade secrets that would likely push research along even faster.
Microfluidic Detectors—Botulinum bacteria produce the most poisonous toxin known. They and similar agents, such as tetanus, could be detected during food processing by microfluidic chips—self-contained diagnostic labs the size of a finger. The University of Wisconsin–Madison is crafting such a chip, lined with antibodies held in place by magnetic beads, that could detect botulism during milk production. The chip could sample milk before or after it was piped into tanker trucks that leave the dairy and before or after it was pasteurized at a production plant. Other chips could detect other toxins at various fluid-processing plants, such as those that produce apple juice, soup or baby formula.
Active packaging—E. coli, salmonella and other pathogens could be detected by small windows in packaging, such as the cellophane around meat or the plastic jar around peanut butter. The “intelligent” window would contain antibodies that bind to enzymes or metabolites produced by the microorganism, and if that occurred the patch would turn color. The challenge is to craft the windows from materials and reactants that can safely contact food. Similar biosensors could react if the contents reached a certain pH level or were exposed to high temperature, indicating spoilage. And they could sense if packaging was tampered with, for example, by reacting to the pressure imposed by a syringe or to oxygen seeping in through a puncture hole.
RFID Tags—Pallets or cases of a few select foods now sport radio-frequency identification (RFID) tags that, when read by a scanner, indicate which farm or processing plant the batch came from. Future tokens that are smaller, smarter and cheaper could adorn individual packages and log every facility they had passed through and when. The University of Florida is devising tags that could be read through fluid (traditional designs cannot) and thus could be embedded inside the wall of sour cream or yogurt containers. The university is also developing active tags that could record the temperatures a package had been exposed to.
Edible Tags—Manufacturers often combine crops from many growers, such as spinach leaves, into a retail package, so tags affixed to bags might not help investigators track contamination back to a specific source. ARmark Authentication Technologies can print microscopic markers that indicate site of origin directly onto a spinach leaf, apple or pellet of dog food using a spray made from edible materials such as cellulose, vegetable oil or proteins. Also, the tiny size would be hard for terrorists to fake, making it harder for them to sneak toxin-laced counterfeit foods past inspectors and into the supply. As an alternative, DataLase can spray citrus fruits or meats with an edible film in a half-inch-diameter patch that is then exposed to a laser beam that writes identification codes within the film.
http://www.sciam.com/article.cfm?id=5-ways-to-keep-food-safe
In the wake of the deadly salmonella outbreak, a look at technologies being developed in the lab to protect us against future eruptions
By Andrew Moseman
<!--/end headline--> During the most recent outbreak of salmonella poisoning, which was connected to peanut butter and other peanut products, the food-borne bacteria has sickened nearly 700 people and may have contributed to the death of nine, the U.S. Food and Drug Administration reports. That came on the heels of an outbreak last summer, finally traced back to jalapeño peppers imported from Mexico, that was responsible for more than 1,400 infections, the U.S. Centers for Disease Control reports.
And when deadly pathogens enter the food supply, the financial costs can add up, too. The peanut butter salmonella outbreak caused the recall of thousands of peanut-related products, and Georgia Peanut Commission executive director Don Koehler says the total loss could be more than $1 billion.
So what are researchers doing to protect our food?
Scientists across the U.S. are using genetics, vacuum pressure, plasma, and other measures to try to prevent the disruptions and tragedies caused by an outbreak. Their research is far from complete but could someday make you feel a lot better about that chicken you're eating
<!--/end picture--> 1. Dr. Keener's Ionizing Ozone MachineScientists fingered spinach as the villain in the September to October 2006 outbreak of Escherichia coli, which sickened 205 and killed three. Now Purdue University's Kevin Keener might have a way to rid microbial infections from the leafy green: plasma.
Keener's device uses high-voltage coils to create a room-temperature plasma field inside a food bag, which ionizes the air inside and creates ozone. Exposure to the gas kills microbes after a few minutes, and it dissipates within 24 hours, Keener says. His lab model cost about $1,500 to build, though he says an industrial-size version could fall more in the $15,000 range.
He says the treatment doesn't leave the food smelling funny, and the slight increase in temperature doesn't cook it. Rather, the hitch thus far is discoloration—ozone also kills chlorophyll—so if there's a cut that allows the gas inside the plant it can partially bleach it.
Carl Batt
<!--/end picture--> 2. Microfluid Chip for Pathogen-TesterOne of the biggest food safety challenges of the modern economy, Cornell University's Carl Batt says, is that our food gets shipped around so much. For the past decade, his lab has been working to downsize pathogen-detecting technology into something just as mobile as our food supply.
Batt's machine extracts a liquified sample of the food and uses a microfluid analysis chip to do a DNA-based scan for the pathogen in question (right now, it's salmonella). The current machine is the size of a suitcase, he says, but the device keeps shrinking as the nanotechnology to move the fluids advances. In the photo, student Sushmitha Krishnan holds the chip for an even smaller model. "People want this tricorder, Star Trek kind of stuff," he says.
So will a tricorder soon be scanning your food for salmonella? Don't count on it. Batt says few of the second-generation, briefcase-size machines are even out there yet. Despite occasional food scares, he says, the market for pathogen-hunting hasn't caught up to the technology yet—Batt says the tester probably costs between $30,000 and $50,000 right now
Doug Powell
<!--/end picture--> 3. Blogging... And Spying on YouInspired in part by the recent move of Butterball's call-in Turkey Talk-Line to the Web and health blogs like WebMD, Kansas State University food scientist Doug Powell decided new media was the way to keep people informed about how to keep up on food safety. So he started Barfblog. This compendium of the disgusting stays up-to-date on food scares and bloggers' own stories when they didn't do so well keeping their own food disease-free.
Powell also wanted to see whether people are learning to follow food safety instructions, so he gathered 40 test subjects—half adults, half adolescents—in a model kitchen with food that's been implicated in disease outbreaks, like chicken thighs. Participants did okay—73 percent washed their hands before cooking, but very few checked their chicken with a internal thermometer when they were done.
Anyway, Powell's not alone as media advocate for food safety. If you need a little silly in your day, check out University of California, Davis, professor Carl Winter's food safety song parodies, like "Who Left the Food Out?" and "50 Ways to Eat Your Oysters."
Jerry Heitschmidt, USDA Agricultural Research Service
<!--/end picture--> 4. Finding Cracked EggsCracks in eggs aren't simply an inconvenience for shoppers, they're also a open door for pathogens to enter. Human inspectors do a decent job at crack detection, catching about 86 percent, according to the U.S. Department of Agriculture. But some cracks are too tiny to be seen, and expand later during shipping and sitting in the store. To solve the egg problem, scientists at the USDA's Agricultural Research Service turned to a vacuum.
Putting a batch of eggs into a vacuum creates negative pressure—the insides of the egg want to get out. If the shell is intact, no problem. But if it contains microcracks, the pressure ruptures them further and makes them more visible to inspectors. In the testing system, each egg gets its own LED light, according to project agricultural engineer Kurt Lawrence, and the researchers use a monochrome camera to take before-and-after photos to notice cracks that expand in the vacuum.
Lawrence says the team has yet to develop a commercial model, but tests of the system showed it was 99.4 percent effective at finding cracks.
Susan Lamont
<!--/end picture--> 5. More Resistant Chickens, Fewer OutbreaksRather than rooting out salmonella from chickens entering the food supply, Susan Lamont of Iowa State University is trying to figure out how to make chickens themselves more resistant to the pathogen. For the last eight years her lab has tried to uncover the genetic reasons why some chickens have more resistance to pathogens than others do.
For example, scientists had known for years that some chickens have greater salmonella-resistance, Lamont says. Genetic studies picked up steam five years ago, when the chicken became the first farm species to have its genome sequenced. Since then, Lamont's been breeding chickens with promising biological markers—groups of genes that seem to correlate with salmonella resistance—to produce generations of more resistant chickens. "We can see what is changing over time," she says.
Poultry companies are doing the same thing, she says, but because the results aren't patented, they're loath to let loose any trade secrets that would likely push research along even faster.
Microfluidic Detectors—Botulinum bacteria produce the most poisonous toxin known. They and similar agents, such as tetanus, could be detected during food processing by microfluidic chips—self-contained diagnostic labs the size of a finger. The University of Wisconsin–Madison is crafting such a chip, lined with antibodies held in place by magnetic beads, that could detect botulism during milk production. The chip could sample milk before or after it was piped into tanker trucks that leave the dairy and before or after it was pasteurized at a production plant. Other chips could detect other toxins at various fluid-processing plants, such as those that produce apple juice, soup or baby formula.
Active packaging—E. coli, salmonella and other pathogens could be detected by small windows in packaging, such as the cellophane around meat or the plastic jar around peanut butter. The “intelligent” window would contain antibodies that bind to enzymes or metabolites produced by the microorganism, and if that occurred the patch would turn color. The challenge is to craft the windows from materials and reactants that can safely contact food. Similar biosensors could react if the contents reached a certain pH level or were exposed to high temperature, indicating spoilage. And they could sense if packaging was tampered with, for example, by reacting to the pressure imposed by a syringe or to oxygen seeping in through a puncture hole.
RFID Tags—Pallets or cases of a few select foods now sport radio-frequency identification (RFID) tags that, when read by a scanner, indicate which farm or processing plant the batch came from. Future tokens that are smaller, smarter and cheaper could adorn individual packages and log every facility they had passed through and when. The University of Florida is devising tags that could be read through fluid (traditional designs cannot) and thus could be embedded inside the wall of sour cream or yogurt containers. The university is also developing active tags that could record the temperatures a package had been exposed to.
Edible Tags—Manufacturers often combine crops from many growers, such as spinach leaves, into a retail package, so tags affixed to bags might not help investigators track contamination back to a specific source. ARmark Authentication Technologies can print microscopic markers that indicate site of origin directly onto a spinach leaf, apple or pellet of dog food using a spray made from edible materials such as cellulose, vegetable oil or proteins. Also, the tiny size would be hard for terrorists to fake, making it harder for them to sneak toxin-laced counterfeit foods past inspectors and into the supply. As an alternative, DataLase can spray citrus fruits or meats with an edible film in a half-inch-diameter patch that is then exposed to a laser beam that writes identification codes within the film.
http://www.sciam.com/article.cfm?id=5-ways-to-keep-food-safe