« February 2007 Table of Contents
Processing & Services: Extending shelf life
Processors try to increase safety, shelf life with dips, sprays and ozonated water
By Lauren Kramer
February 01, 2007
Shelf life is a pivotal concern for all companies handling a
perishable commodity like seafood. Processors constantly
grapple with handling and shipping seafood products as fast and
as safely as possible so that their customers have a quality
product to sell. They know that the shelf-life clock begins
ticking as soon as seafood leaves the water, and every step
along the supply chain can affect a product's safety, taste and
Some processors preserve seafood's shelf life by doing their
best to manage the product's time and temperature and avoid
using secondary treatments at all costs. Others embrace an
array of new products that have debuted over the past five
years, among them sprays, dips and ozonated water generators.
These products promise to increase sanitation on the processing
line, thus extending product shelf life, while decreasing the
presence of Listeria and other pathogens that can often plague
Frank Costanzo, plant manager at Service Smoked Fish in
Brooklyn, N.Y., believes that, for the most part, chemicals are
an unwelcome addition to seafood products. "Nobody wants to
read a long list of chemicals on the ingredient listing of
their food in general," says Costanzo. "Most of us don't want
to say 'my compliments to the chemist.'"
The one exception Costanzo makes is for Keeper, an
antimicrobial rinse designed specifically for the seafood
industry and manufactured by Bio-Cide International of Norman,
"If there's a silver bullet for Listeria, this is it,"
declares Costanzo. Service Smoked Fish produces a full line of
hot- and cold-smoked seafood and distributes it to bagel shops,
delis, restaurants and caterers, and has been using Keeper for
two years. "When you're using this stuff, you do not get
positives for Listeria. Keeper has a long-term kill and then it
evaporates, turning into water vapor and table salt. It's the
only product I know of with Food and Drug Administration
approval that can be applied directly to a ready-to-eat product
with no rinsing required."
Keeper is based on acidified sodium chlorite, which
generates chlorine dioxide, an antimicrobial with the efficacy
to kill pathogens. At this point, it becomes table salt and
presents no hazard to the seafood product it touches.
Raw seafood can be sprayed with Keeper, or dipped into a
solution containing the product. Alternatively, Keeper can be
used in water to create the ice that seafood is processed or
stored on. It retails for $24 to $32 per gallon, and each
gallon creates 400 gallons of rinse.
"On average, Keeper extends the life of frozen seafood by 30
days, increasing its shelf life by 10 to 20 percent," says
Scott Owen, director of technical affairs at Bio-Cide. "Fresh
seafood doesn't have a long shelf life, so adding even a day
will make a big difference, but specifically how much of a
shelf life extension you get depends on the product."
Another product promising to extend shelf life is Pacific
Blue Seafood Spray, which claims to reduce seafood spoilage by
up to 30 percent. Manufactured by Tasker Capital Corp. in
Danbury, Conn., this antibacterial treatment uses Tasker's
patented pHarlo technology and has been on the market since May
"The major ingredients are ammonia sulphate, sulphuric acid
and copper sulphate," says Richard Falcone, president and CEO
of Tasker. "Its ingredients are all recognized as safe by the
FDA. Moreover, depending on what stage the seafood is at when
you introduce Pacific Blue, it can double the shelf life."
Pacific Blue comes in two forms: a seafood wash that
retailers use to spray or dip seafood into, and a concentrate
for seafood processors to add to water lines or ice
machines. Twelve bottles containing three gallons of Pacific
Blue retail for $100 and a typical grocery store fish counter
would require one to two bottles a day, according to
An independent toxicology study at Mississippi State
University found that Pacific Blue had no negative effects on
seafood, and that it also worked well as a cleaning and
disinfecting agent for surfaces. "We've found Pacific Blue to
be effective both as an antimicrobial that can double the shelf
life of seafood, and as an agent to help decrease seafood
odors," says Juan Silva, professor of food processing and
safety at MSU.
For some seafood processors, the expense of dips and sprays
renders their use prohibitive. "The only thing we wash our
fillets with is natural salt brine, and we've had reasonably
good success with it," says Roy Zaffiro, spokesman for Channel
Fish Processing in Boston. "We've tried other products, but we
felt that there wasn't enough value for what we were paying for
Many processors have extended product shelf life and
significantly decreased instances of Listeria and other
bacteria by using ozone.
AMFIL Technologies in London, Ontario, supplies ozone-based
mPact™, a cleaning antimicrobial system for food and beverage
processors that uses ozonated low- and high-pressure cold water
for food processing lines and processing equipment.
One of its clients, a leading Canadian fish processor, paid
$30,000 for its mPact™ unit. But it also reported that by using
mPact™ it was able to reduce Listeria counts in its whitefish
caviar by 98 percent compared to the previous year's microbial
sampling data, and an increase in shelf life of two days on
Ronnie Wrenn, president of Fresher than Fresh, a Gastonia,
N.C., seafood products distributor, has used ozonated water in
its processing line for the past two years, and noticed a huge
difference in overall bacteria count since its
"Ozone is an electrically charged oxygen gas with a half life
of 20 seconds," says Wrenn. "Bacteria need oxygen to multiply,
and when aerobic bacteria comes into contact with ozone, it's
"We have had no complaints about our product not holding up
for the 10 days we guarantee it for since we started using this
system," he says.
The biggest difference we've seen is in headed and gutted
fish, which are the hardest to keep clean because they still
have the body cavity attached. The ozone bath knocks down the
bacteria count in the body, giving us the same shelf life for
headed and gutted fish as for the fillet products we pack. It's
a difference like night and day."
Ray Swenton, president of Bristol Seafood in Portland,
Maine, has had a similar experience since he switched from
chlorine to ozonated water six years ago. "All our ice, fresh
water and washing water is treated with ozone, and since we
started using it, our bacteria has been reduced by almost 75
percent on all surfaces and water drainage areas," he says.
"Both the shelf life of our seafood, and our sanitation in
general, has been dramatically improved."
An ozone generator costs between $15,000 and $35,000
depending on the water flow and size of the processing plant,
according to Peter Rubenstein at Pressure Techniques, which
generators manufactured by Clearwater Technology in
California. Installation, which involves
changing the water
piping in the plant to ensure it is non-corrosive, can add an
additional $2,000 to $10,000, while annual maintenance averages
Once it's all done, however, the results are well worth it,
according to Swenton. "All you're really doing is paying for
electricity, because it runs off electricity and water
pressure," he explained. "You don't have to worry about
chemicals or hazard analysis, because there's nothing hazardous
about it, nor is there a residual smell, taste or odor. It's
simple, easy to use and it's 99.9 percent effective."
What's more, it increases the shelf life of seafood by up to
four days on a bacteria-free product, says Jerry Knecht,
president of North Atlantic, also in Portland. "We run a 99
percent bacteria-free plant and product, and we've had neither
Listeria nor any pathogens since we've started using ozone
two-and-a-half years ago," he says.
Knecht had previously tried a few other methods to extend
shelf life, including chlorine and NutraPure. "The problem with
chlorine was you never knew when it was used up. The ozone
costs less, and it's constantly effective," he said.
The processor also tried NutraPure, a technology developed
by Gloucester, Mass.-based Proteus Industries. NutraPure is
created by extracting protein from fish trimmings. Excess water
is removed from the trimmings and the protein is then injected
back into seafood, resulting in a shelf life increase of two to
three days longer than untreated seafood, according to Stephen
Kelleher, Proteus president.
North Atlantic tested it from 2005 to 2006. "We found that
the industry was not ready for that application and would not
pay for it, regardless of the benefits,"
One company that takes the worry of microbial counts out of
processors' hands is Global Food Technologies, with its iPura
"Clean Step Process." The Los Altos, Calif., company's patented
processing machine uses mechanical properties such as pressure,
vacuum and temperature together with an environmentally safe,
organic antimicrobial to reduce bacteria on seafood
"We provide the equipment, clean room, antimicrobial
solutions, technology and personnel," says Robert Clark,
director of marketing at GFT. "The seafood enters a vessel that
changes PH, temperature and most importantly, pressure. Several
minutes later, the seafood is packaged and then shipped, with a
microbial count thousands of times lower than existing
processes - all natural. The taste, color, texture and
nutritional value are not affected and less pathogens at
shipping means a dramatically extended shelf life."
Chilean salmon and Vietnamese shrimp are the first two iPura
products that will appear on grocery store shelves
internationally in the second quarter of 2007.
As the seafood shelf-life clock ticks on, it's prudent to
stay abreast of new products that promise enhanced sanitation
and freshness preservation. While no product can promise a
completely bacteria-free environment, a few come as close as 98
and 99 percent - which means the bacteria battle has a clear
Contributing Editor Lauren Kramer lives in British