Radio Script
2004

Graduate student Jiraporn Chantarachoti uses a commercially available electronic nose to test the freshness of canned Alaska salmon. University of Alaska Fairbanks scientists are working with funding from Alaska Sea Grant to test two models of electronic noses, in hopes of improving Alaska seafood quality. (Courtesy Alexandra Oliveira)

Electronic Nose Sniffs Bad Seafood
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INTRO: The best way to tell how fresh the seafood is that you're about to buy from your local fishmonger, is to give it a sniff. If it smells, well, fishy, then it's not fresh. It's low-tech, but it works. Now researchers say there may be a better way.

STORY: When it comes to ferreting out spoiled fish, the nose knows. Our olfactory sense has for years been the instrument of choice for consumers and even seafood inspectors. But after a few hours' smelling fish, even the best nose can come up a bit short. Our sniffers are, after all, only human.

But technology may soon come to the rescue. In the near future the electronic nose—a technological marvel that will never catch a cold, become stuffy or sneeze—may replace the human nose. Alex Oliveira is a researcher at the University of Alaska Fairbanks Fishery Industrial Technology Center in Kodiak, Alaska.

OLIVEIRA: "We are trying to apply a technology that is fairly new. Several industries use a variety of electronic noses for specific purposes, such as control of raw material coming in to processing plants. The electronic nose would be a quick, easy way to indicate: Is it within limits of acceptance or is it out of the limits of acceptance?"

Oliveira and colleagues Chuck Crapo and Brian Himelbloom, together with graduate student Jiraporn Chantarachoti, are this summer testing two types of commercially available electronic noses to see if they might be used to boost seafood quality in Alaska's processing plants. The research is among nine new projects being funded by the Alaska Sea Grant College Program over the next two years, to better understand and use Alaska's marine resources.

Perhaps the best-known electronic nose is the breathalyzer, a device used by police to determine if someone has drunk too much alcohol. Oliveira says the electronic noses she's testing work in a similar fashion—they detect volatiles, or gases, given off by decomposing fish long before the spoilage would be apparent to our merely mortal human nose.

OLIVEIRA: "The first one is called the Cyranose, and it's composed of 32 sensors. These sensors interact with the volatiles of the sample. And it results in a pattern of recognition that might aid in quality control, as for example product spoilage. The patterns of the volatiles change, and with that you can do quality control."

While the Cyranose is able to detect the gases associated with spoilage, a second type of electronic nose, called a zNose, is able to also determine the exact cause of the spoilage. Initially, Oliveira says, the sensors will be used to measure the amount of ethyl alcohol found in canned salmon coming out of Alaska's processing lines.

OLIVEIRA: "There is some controversy as to why ethanol is present in canned salmon. Ethanol is most likely from bacteria spoilage. But what they don't know is if the bacteria spoilage causes a compound to form that after retorting (cooking) generates ethanol, or if the bacteria generate ethanol as a byproduct of its metabolism."

Eventually, Oliveira hopes electronic noses will be used throughout the seafood industry to ensure only the freshest seafood reaches consumers. But there's a lot of work ahead before that can happen. She says research is needed to decide just what constitutes a fresh fish, at least as far as an electronic nose is concerned. And freshness may also differ among species of salmon. For this, she says, many fish would have to be tested and standards developed.

OLIVEIRA: "The ultimate goal would be to get a profile by species of salmon. Pink salmon would have specific profiles of spoilage—odors that would show up from fresh, to less than fresh, to spoiled. It might be different for fattier fish like king salmon. You train the electronic nose to do this evaluation and then it becomes a quality control tool."

Oliveira says electronic noses should help processors improve the quality of their salmon and other seafood products.

OLIVEIRA: "It improves their ability to discriminate between a bad and a good product in real time. This would be very valuable to processors because a lot of times they are buying fish from a number of boats on the fly as the fish are coming into the plant. And then the other point is to try to avoid sending out product that is unfit."

Eventually, Oliveira hopes electronic noses will become small enough and portable enough to be used in supermarkets and restaurants, and maybe even your own home.

This is Arctic Science Journeys Radio, a production of the Alaska Sea Grant Program at the University of Alaska Fairbanks School of Fisheries and Ocean Sciences. I'm Doug Schneider.

Thanks to the following individual for help preparing this script:

Dr. Alexandra Oliveira
Fishery Industrial Technology Center
118 Trident Way
Kodiak, AK 99615-7401
Phone: (907) 486-1530
ffamo@uaf.edu

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Related Web sites

Alaska Sea Grant College Program

Alaska Sea Grant Project Directory 2004-2006

Alaska Sea Grant Project: Quality Inspection of Alaska Salmon Using Two Portable Odor Detection Devices

Fishery Industrial Technology Center

National Sea Grant News and Events: Electronic Nose to Check Salmon Quality in New Alaska Research Project

Principal Investigator Profiles

Dr. Alexandra Oliveira

Dr. Charles Crapo

Dr. Brian Himelbloom

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