Pure Tech, Inc.Pure Tech Online

Home ] Up ] AquaCulture ] FAQ - ClO2 ] Federal Regs. ] C. Fishing ] S. Processing ] Tests ] Products ]



Seafood Business-8/00



Processors tend to shy away from chemicals, even those that can enhance product quality and extend shelf life

By Sue Robinson


Paul Taylor, owner of Evergreen Food Ingredients, has seen first-hand the resistance to change in seafood marketing.

Taylor helped introduce a product called Fish-Plusâ to the seafood industry in 1981. This was a patented combination of phosphate, citric acid, and sorbate – all common food ingredients generally recognized as safe by the Food and Drug Administration – that would extend the shelf life of a fillet from the usual four to five days to 10 to 14 days, maintaining quality throughout the period.

“The product never caught on, not because it didn’t work, but because a few influential marketers didn’t want to have to declare the added ingredients on their product labels,” Taylor says. Fish-Plusâ is no longer being marketed.

Taylor is not alone in his experience. The biggest obstacle for the makers of additives and preservatives is how their wares are perceived by an industry that has always been leery of using chemicals on its products.

For years, preserving seafood meant salt, smoke and ice, and for many processors, it still does. When they are asked what additives they use, invariably the response is either, “We don’t use any,” or “Our seafood is 100 percent natural”.

But two developments are causing a shift in attitude: the federally regulated HACCP program, which set standards for fish handling and fish safety, and the increasing demand for value-added products. The seafood industry is slowly realizing that “preservatives” is not necessarily a dirty word.

While manufacturers of preservatives and additives are offering up a host of dips, rinses, feed supplements and ice soaks, a trend toward natural extracts is allowing processors to extend shelf life or retain moisture while playing true to their “100-percent natural” claim.

But one of the biggest challenges for the manufacturers of these products is communicating that information to potential clients.

Preservatives got a bad wrap when seafood processors tried using chemicals that were not yet regulated. For example, sulfites, now restricted by the FDA, helped keep shrimp shells from turning black but could be fatal to asthmatics allergic to the chemical.

“There are a significant number of people out there trying to come up with some new things for seafood, and we are a lot more sophisticated than we were 10 years ago,” says Dan Herman, director of regulatory affairs at the National Fisheries Institute.

He adds, “Part of the catch is that people really want to market a majority of their fish as naturally as possible without any additives or processing.”

Be that as it may, Taylor says, “The seafood industry would be better off if the marketers did a bit of education and showed the consumer that the application of safe ingredients could improve eating quality, reducing spoilage losses and even reduce the cost of seafood distribution.”

Seafood additives perform a wide variety of functions. They can be natural or synthetic, but all must be approved by the FDA.

There are four basic uses for food additives: fortification (e.g. vitamins), cohesion (to stabilize texture), extension of shelf life, and preservation of natural flavor and color. Additives in the last two categories are called preservatives.

Some fairly new products are gaining attention, including chlorine dioxide, new phosphate blends, more effective feed supplements and natural substances that act as antioxidants to slow spoilage.


Chlorine dioxide

            For years seafood processors put chlorine in their water systems as the sole method of sanitizing fish and equipment. But five to 10 years ago, processors discovered a different compound – chlorine dioxide. This compound not only sanitizes equipment more effectively, but it can be used as a dip or a rinse for seafood, either in the ice aboard a boat or at the processing level.

            The “preservative” notation need not exist in this case because the product is not added into the fish.

            While chlorine produces a chemical reaction that causes carcinogens such as dioxins and trihalomethanes, chlorine dioxide is reduced to chlorite, which is found in sea salt.

            When used on fish, chlorine dioxide serves as an anti-microbial agent, targeting salmonella, Listeria, E. coli, campylobacteria and Entobacteriaceae.  When used in ice, it extends the shelf life of iced fish by five to seven days. Processors like chlorine dioxide because it has a 99.9 percent kill rate and will not lose its effectiveness. 

            “For years, processors were using other compounds [for sanitation] and had to change product solutions every three to four days, because the bacteria get used to them. It became very costly,” says John Burgos, president of Pure Tech of Hyannis, Mass. His company markets two chlorine dioxide products for seafood – Supreme Blend and the Keeper.

            The equipment and chemical mix for chlorine dioxide cost anywhere from  $2,500 to $3,500, depending on the size of the machine and whether it will be used as an equipment sanitizer or as a seafood rinse.



            Processors have often used phosphates, primarily sodium phosphates, to retain moisture in seafood. These agents are also sometimes used to help bind muscle protein, especially in minced products, improving texture and eating quality.

            “ We need to use something to retain the color and texture of the product, or people won’t buy it,” says Richard Sante, president of crab importer Miami Crab Co. in Florida, which cans and pasteurizes blue crab. Miami Crab uses sodium acid pyrophosphate to preserve texture and keep the product from drying out.

            Now, some manufacturers offer specialized blends of various phosphates with other ingredients (such as carrageenan and soy protein, which are both used to maintain fish texture). Blends allow processors to utilize the properties of several chemicals at once.

            The phosphates are sold as dry powders or granules and may be added dry or dissolved in water for use as a dip, depending on the application.

            Other ingredients have been found to promote seafood’s shelf life. One is sodium lactate, which extends shelf life slightly and is effective against Listeria.

            “It depends on what the customer wants. Whatever they need can be mixed up or supplied for almost any specialized purpose they have,” says Evergreen’s Taylor.


Feed supplements

            Manufacturers of feed for farmed fish can mix up whatever additive is need to enhance the quality and appearance of the end product. Synthetic vitamins, antioxidants and pigmentation are all added as aquaculture feed supplements and do not have to be listed on the product.

            Consumers tend to think of farmed salmon as pure and natural. But many people do not realize that without a feed additive, farmed salmon would not develop their characteristic rich, orange flesh coloration, since their diet lacks natural pigmentation.

            Processors can choose the exact shade of flesh color they want in their fish flesh and use the appropriate feed additive to achieve it.

            “People want to harp on the fact that we use it, and refer to it as Red Dye No. 3,” says Tom Royal, president of Atlantic Salmon of Maine. “In fact, it is an exact chemical replica of the red pigmentation found in the wild.”

            Roche Vitamins of New Jersey has spent years perfecting synthetic pigmentation, called carotenoids – in particular, astaxanthin, which can also act as an antioxidant for disease immunity.

            Feed supplements have been perfected to increase productivity as well. For example, 1.1 pounds of feed is converted to 1 pound of flesh, according to Royal. Ten years ago, that ratio looked more like 1.3 to 1.

            The only drawback is that the feed additive is expensive - $200 per ton of feed.


“Natural” additives

            Some processors are hoping to bring down cost by developing “natural” pigmentation. NFI’s Herman says that researches at various universities are trying to come up with an herbal extract to use in manufactured pigment for feed. Currently, no such product exists to enhance the color of fish flesh.

            However, Kalsecâ has developed a natural answer to synthetic antioxidants, which extend shelf life by inhibiting oxidative rancidity – a primary cause of off odors and flavors in seafood. The company’s Duralox Oxidation Management Blends are based on Herbaloxâ Seasoning, which is Kalsec’s patented preparation of rosemary extract.

            Duraloxâ blends are liquids designed to be completely soluble in dipping, glazing and pumping solutions. They are a mixture of rosemary extract and other natural ingredients like citric acid, ascorbic acid or tocopherol.

            “They function by protecting fish oils from oxidation and can produce two or three-fold improvements in shelf life,” says Gary Hainrihar, vice president of sales and marketing for Kalsec.

            “They work synergistically to extend shelf life while permitting a consumer-friendly label statement.”

            This trend allows chemical-wary seafood sellers to apply beneficial additives to a product they can still tout as natural. Without some sort of preservative, such as an antioxidant or an enzyme inhibitor to maintain muscle tone, fresh seafood spoils in a matter of days.

            Yet, despite the advantages additives offer, processors are resistant to using them, say the manufacturers of these products.

            Dennis Reid, food and beverage manager at Ohio-based Ashland Fine Ingredients, admits, “There are a lot of negative perceptions out there.” His company sells an extensive line of food additives for use in dips, rinses and injections.

            Reid says it is sometimes difficult to convince seafood processors that their product can benefit from phosphates, which retain moisture; preservatives, which prolong shelf life; and antioxidants, which prevent rancidity.

            “What they don’t understand is that for extended shelf life and acceptable quality, these ingredients are a necessary evil,” he says.

            Processors may yet be forced to rethink additives. In world with fewer fish and more competitors, there’s greater demand for value-added products – items that must please a wary customer who is increasingly distanced from the product’s origin.

            “I have to say that right now the seafood industry does not use to its potential [the additives] out there on the market, but until now they did not have to,” says Reid, citing the minimally processed and frozen products traditionally found in the marketplace.

            “The more convenience and variety that the consumers look for, the further processed the industry goes. With [processing] comes a need for more functional food additives – whether they like it or not.”


Sue Robinson is a freelance writer in Vermont. She can be e-mailed at srobinson@divcom.com

Printed with permission from Seafood Business Magazine


Home ] Up ] Contact Us ] Site Map ] About Us ] Terms of Use ]


Copyright© 2001 Pure Tech, Inc.